A Critical Review of Developers’ Decision Criteria for Brownfield Regeneration: Development of the BRIC Index

Abstract

The complexity of processes and constraints associated with redevelopment of brownfield lands calls for provision of relevant, adequate, sufficient, up-to-date, and easily accessible information on brownfield lands to enable developers make an informed decision when navigating the hurdles of brownfield redevelopment. Furthermore, the various obstacles and barriers that developers encounter during decision making for brownfield redevelopment has continued to contribute to the limited uptake of brownfield lands in England by developers for redevelopment and regeneration. This study was conducted to explore the factors that developers consider when redeveloping brownfield lands and to present a decision criterion that will support brownfield site selection and subsequent regeneration. A mixed methodology using qualitative and quantitative approaches was adopted to investigate the factors, criteria, and information that developers consider when making decisions for brownfield redevelopment. Data collection was carried out using a literature review and interviews with brownfield experts. Using a purposeful sampling approach, a total of 11 brownfield stakeholders, which cut across key experts involved in brownfield redevelopment within the Black Country region of England, was interviewed. Each expert interviewed holds a stakeholder critical role in regulatory organisations and construction industry organisations, including local authorities, geo-environmental organisations, land remediators and consultants, housing developers, etc. A comparative analysis of evidence obtained from developer interview responses, the literature review, and the brownfield register showed that 57% of factors, criteria, and information such as cost/capital expenses, funding, contamination level, infrastructure, water risk, neighbours, connectivity (digital, energy networks/grid), and access and transport, which developers require for decision making relating to redevelopment of brownfield sites, are not available on a standard local authority’s brownfield land register. To address the identified information gaps, this study developed “The BRIC Index”, a decision-making tool that incorporates a GIS-based system to facilitate screening of brownfield sites based on specified criteria and to help identify risks, contamination, and remediation costs of brownfield development. The effectiveness of the BRIC Index was validated through successful usage for site selection by various SMEs in the Black Country.

1. Introduction

Brownfield sites are lands that have previously been built on and now sit derelict, contaminated, vacant, or partially occupied due to a number of factors including risk of pollution, cleaning cost, and so on. In the UK, brownfields sites are sometimes referred to as industrial land because many of them were previously developed during the industrial revolution, which occurred in the 18th and 19th centuries. A large number of brownfield sites has accumulated on the UK landmass due to the high intensity of industrial activities, such as textile manufacturing [1], and industrial infrastructure developments including large-scale industry, mechanized manufacturing, and large factories that took place on the British landscape during the industrial revolution. To this end, the UK has over 400,000 hectares of contaminated landscape [2], and more brownfield sites have continued to be discovered across local authorities in England on a yearly basis. For example, as of November 2021, the total supply of brownfield lands across the regions in England stands at 21,566 brownfield sites covering 26,256 hectares of lands with a capacity for development of 1.16 million new homes [3]; however, by November 2022, the total stock of brownfield lands across regions in England increased to 23,002 brownfield sites covering 27,342 hectares with a capacity for a minimum of 1,232,592 housing units [4].

Regeneration of brownfield sites can bring about many benefits including economic prosperity vis-a-vis infrastructural development, the circular economy relating to reuse and recycling, product development, job creation, the tackling of scarcity of available development lands through increased land development and reduced pressure on greenfield land, sustainable development in terms of regenerating and increasing housing supply in neglected communities, and the conservation of greenfields, woodlands, and habitats for protection of the environment ([2,5,6,7,8,9]).

Various case studies of brownfield redevelopment in the UK have proven that remediation of brownfield sites helps to create economic prosperity through opportunities for infrastructural development. When the contamination on land is cleaned up, the land can be made fit for specific purposes and be brought back into use for new developments. A typical and popular example is the remediation and transformation of a 350-hectare area of East London into the London 2012 Olympic Park. In terms of infrastructural development benefits, the London Olympic Park hosted a highly successful Olympic and Paralympic games attended by over 800,000 people in 2012 ([2,10]), became a legacy and the largest urban park in Europe with 100 hectares of open land and 45 hectares of new habitat, and it is currently housing about 2800 new residents in its Athletes Village. In terms of adopting circular economy principles, 80% of materials excavated from the London 2012 Olympic Park during the remediation phase was reused on the same site as engineering fill during the redevelopment phase. Furthermore, 250 litres of free products (including hydrocarbons) were removed from the chemical contaminants cleaned from the London Olympic Park, while 23,500 m² of contaminated groundwater was pumped and treated for reuse ([2,6]).

However, owing to the complex nature of the processes involved in brownfield redevelopment plus the various associated obstacles and barriers as outlined in CPRE (2014) [11] and CPRE (2021) [3], the uptake of brownfield lands in England by developers for redevelopment and regeneration has been limited. According to CPRE (2014) [11], some of the barriers and obstacles contributing to the limited uptake of brownfield lands for redevelopment in England include land ownership obstacles, physical obstacles relating to site preparation costs, the shifting of remediation cost and clean-up liability to developers, the non-sequential approach to land allocation in the National and Local Planning Policy, and insufficient efforts to allocate small scale brownfield sites with high housing capacity. Other recently identified obstacles to brownfield redevelopment in England include limitations associated with local authorities’ published brownfield land registers comprising complicated accessibility, non-transparent and less-frequently updated information on brownfield lands, inconsistent and inaccurate data, obsolete/altered templates, and the exclusion of small brownfield sites from brownfield registers. Out of the total of 26,256 hectares of brownfield lands in England, only 5172.74 hectares (20%) were built out (redeveloped) between 2016 and 2021 [3], which is a shortfall compared to the initial target of 90%. Similarly, in the West Midlands region of England, only, 313.11 (9%) hectares out of a total of 3479 hectares of brownfield lands have been built out as of 2021. In the Black Country Metropolitan District Council areas of the West Midlands, 69% of the total 18,368 brownfield housing capacity have been granted planning permission as of 2021, although there is limited information on when these planning permitted sites will be redeveloped. The Black Country district councils with the highest number of housing units with planning permission for redevelopment on brownfield land is Sandwell (9569 units), followed by Walsall (1381 units), Wolverhampton (973 units), and Dudley (749 units) [12].

It is well documented that the Black Country, which is a region within the West Midlands region of England, UK, has a record of industrial heritage that dates back to the 18th century [13], and this explains why the region houses many brownfield sites that have remained untapped to date. As part of efforts to address the persistent low uptake of brownfield lands for redevelopment in the West Midlands and the Black Country region of England, this study explores the factors that developers consider when redeveloping brownfield lands and presents a decision criterion that will support brownfield site selection and subsequent regeneration. The criteria-based brownfield indexing database, namely, the BRIC Index, is also introduced. The BRIC Index is newly developed software that developers can employ to search, scan, and identify brownfield lands that can be considered for redevelopment and regeneration within the Black Country, West Midlands Region of England.

2. Literature Review

Many studies [5,14,15,16,17,18,19] have explored the subject of brownfield selection criteria. To address the challenges of the brownfield information gap, the literatures selected for review in this study consist of two categories; category one covers existing studies that proposed systematic solutions for encouraging evidence-informed land selection methods, and category two are those that outline brownfield selection factors.

2.1. Systematic Solutions for Brownfield Land Selection Methods

In terms of systematic solutions for brownfield land selection methods, researchers have explored various methods, including the Smart Growth Network model, Thomas GIS model, the Probit model, the spatial discrete model supported by GIS data, the indexing method, cost-benefit, multivariate analysis, etc. For example, Kurtovic (2014) [14] investigated approaches for the identification of brownfield sites and concluded that the optimum approaches are the Smart Growth Network model, which entails the selection of developable brownfield sites based on economic feasibility and social and environmental benefits, and the Thomas GIS model, which incorporates geographic spatial and socio-economic data for the selection of brownfield sites based on the ranking of certain criteria at the local and state level. Other methods identified by the study include the indexing method, cost-benefit, and multivariate analysis.

Over the years, GIS has been used as a system for the management, manipulation, representation, and analysis of geospatial data to facilitate and reduce costs in the site selection process [20]. The goal of a site selection exercise is to find the optimum location that satisfies several predefined criteria [21]. The process of site selection typically involves two main phases: screening (identifying a limited number of candidate sites from a broad geographical area given a range of selection factors), and evaluation (in-depth examination of alternatives to determine the most suitable site) [22]. A multitude of sometimes-contradictory factors is involved in both phases. In such a situation, several tools are available to determine the optimum site. These tools include Expert Systems (ESs) for well-defined and structured problems and Decision Support Systems (DSSs) for ill-structured problems or their combination [21,22,23]. To this end, combining a GIS with Multiple Criteria Decision Making (MCDM) techniques can facilitate site selection in cases where the problem is ill-structured or semi-structured, that is, in situations where decision-makers do not have complete and reliable information regarding specifications, alternatives, and outcomes. This explains the suitability of the decision-making tool that incorporates a GIS-based system to facilitate screening of brownfield sites based on specified criteria.

2.2. Brownfield Selection Factors

To address brownfield information challenges, existing studies have identified several brownfield selection factors including site size, neighbourhood land use, funding and incentives, the nature of contaminants, clean-up liabilities, waste treatment and waste disposal liabilities, the prosperity of the municipality or region, the proximity of brownfield land to existing settlement systems, the proximity of brownfield land to transportation infrastructure, previous land uses of brownfields, the threat of environmental liability, etc. Alberni (2007) [15] analysed the determinants of brownfield remediation in Colorado, USA, with the aid of a Probit model on 432 brownfield sites and concluded that the determinants of brownfield redevelopment are site size and neighbourhood land use. The provision of economic incentives is reported in the literature as another factor that contributes to successful redevelopment of brownfield sites [24]. Similarly, Dixon et al. (2006) [16] investigated the criteria that aids brownfield redevelopment decisions using structured interviews of 11 developers and mailed surveys of 987 commercial developers and residential developers in United Kingdom; they found that funding and incentives made available by the government were the main factors encouraging brownfield redevelopment. Further, developers are often discouraged from regenerating brownfield sites when there is limited information on site conditions, the nature of contaminants on the land, the clean-up liabilities, and the ambiguities relating to specifics on how to comply with treating waste disposal. Osman et al. (2015) [17] reported, based on a literature review, that the factors that influence the reuse of brownfields include the prosperity of the municipality or region, the proximity to existing settlement systems, the proximity to transportation infrastructure, previous land use of brownfields, and most importantly the threat of environmental liability. Using a spatial discrete model supported by GIS data, Longo and Campbell (2017) [5] analysed England’s national land use database, which contains a register of over 21,000 brownfield sites, and found that neighbourhood infrastructure, location, size, and ownership are some of the factors that aid reuse decisions of brownfield sites. A study conducted in the USA by Lange and McNeil (2004) [18] reported that proximity of brownfield sites to infrastructure such as airports, city centres, and railway attracts redevelopment. Novosák et al. (2013) [19] pointed out that in Ostrava in the Czech Republic, the decision to regenerate brownfield site is mainly affected by two major criteria: site contamination and previous land use. The factors identified from the above-mentioned literatures show that amongst others, some of the most common factors/criteria that developers look for when considering redevelopment of brownfield land include remediation cost, funding, contamination level, site size, future land use, land ownership, etc. Each of these factors are explained in detail in Section 2.2.1, Section 2.2.2, Section 2.2.3, Section 2.2.4, Section 2.2.5 and Section 2.2.6 below.

2.2.1. Remediation Cost

Multiple studies [11,16,24,25,26,27] have shown that the cost and capital expenses associated with redevelopment of a brownfield site are some of the criteria that influence a housing developer’s decision to redevelop a brownfield site. In redeveloping a brownfield site, developers could incur various “abnormal costs” (i.e., costs that are not likely to occur in the case of developing a greenfield site). Some of the abnormal costs associated with the redevelopment of brownfields includes costs for demolition, removal of contaminants, land taxes, the importing of clean soil, planning issues, ground conditions, conservation, etc. [11]. Case studies of previously remediated and redeveloped brownfield sites have shown that brownfield lands are associated with high redevelopment costs, and the actual commercial viability of brownfield redevelopment is often assessed based on the costs associated with remediating and decontaminating the site. For example, a remediation cost estimate guide published by the Home and Community Agency (HCA) in 2015 shows that depending on the previous use and the proposed future use, the cost of remediating a brownfield could range from GBP 50,000 to over GBP 1 million per hectare [28]. The Local Authority Building Maintenance also reported that the cost of remediating a brownfield could range from GBP 25 K to GBP 100 k per acre, in addition to the separate cost of pilling and grouting [29]. Other factors that influence the remediation costs of brownfield sites include the proposed end use, water risk, number and duration of previous uses, site size, site location, site history, geology, level and depth of contamination, and remediation strategy/contractors [28]. Furthermore, the potential hidden risks associated with brownfield lands often present uncertainties in estimating the costs of brownfield remediation. As such, at the stage of contract exchange for brownfield redevelopment, developers are usually keen not only to know the potential cost/capital expenses that may be incurred in remediating a typical brownfield but also to deduct all the abnormal development costs from the asking price of the brownfield site [11]. Hence, the availability of a database that will facilitate the transparency on the potential costs of remediating brownfield lands is important to enable developers to make informed decisions around redeveloping brownfield land.

2.2.2. Funding

The majority of housing developers in England are private sector volume house builders whose business survival depends on the financial viability of the housing development schemes in which they engage [30]. Studies [16,24,31,32] have shown that the availability of funding, such as financial incentives and grants for cleaning up and for redeveloping brownfield site, is one of the factors that have been encouraging developers in England to consider redevelopment of brownfield lands for housing projects. Findings reported based on a survey and structured interviews of 987 developers in England showed that the availability of financial incentives and funding is the most favoured criteria for brownfield redevelopment [16]. Ecker and Keeler (2012) [31] also reported that most brownfield sites are remediated with the aid of funding and incentives from government, and that the level of such funding depends on factors including ownership, clean-up liability, level of contamination, and the viability of the site for redevelopment regarding whether the profits obtainable/returns on redevelopment will outweigh the potential risks of the site. Further evidence reported by Geideman et al. (2004) [32] in a study that analysed development trends in real estate and environmental databases of over 700 brownfield sites in Cook County, Illinois, USA, showed that 20% of those sites benefited from infusion of funding from government, and this facilitated less-expensive remediation and easy redevelopment of the concerned sites. According to RICS (2012) [33], financial viability in property development is the “ability of a development project to meet its costs including the cost of planning obligations, whilst ensuring an appropriate site value for the landowner and a market risk adjusted return to the developer in delivering the project”. The high preference given to funding is since the high development costs and financial risks associated with brownfield redevelopment may impact developers’ target investment budgets. To this end, developers may choose not to build on a brownfield site if the associated land expenses and the potential level of contamination present large financial risks for the developer.

2.2.3. Contamination Level

The level and type of contamination of brownfield sites varies and largely depends on the previous industrial activity that took place on the site (or that the site was used for) during the industrial revolution. As a result of historical operational usage or current usage of lands or properties for industrial or non-industrial activities in which chemicals were used, produced, reclaimed, stored, and disposed, contaminations present on brownfields sites may originate from general contaminant groups including halogenated VOCs, non-halogenated VOCs, halogenated SVOCs, non-halogenated SVOCs, fuels, metals and metalloids, and explosives [34]. Regardless of the scale and type of contaminant, every contaminated brownfield land presents the housing developer with concerns relating to environmental compliance, financial risk, expensive engineering and clean-up, liability issues, neighbourhood opposition, etc. As such, awareness of the contamination level is one of the most important criteria that developers consider when making decision to regenerate brownfield sites. Furthermore, brownfield redevelopment is regarded as a real estate investment that often necessitate the need for developers to obtain funds/loans from banks and other financial providers. In cases like this, developers tend to avoid sites with a certain type and level of contamination because lenders’ perceptions of investment risk and decisions to provide loans or otherwise are usually influenced by the presence of contaminated soil and groundwater on a brownfield site [24]. For example, whilst land remediators may be interested in highly contaminated sites with previous histories of landfills or quarries, Schwarz et al. (2009) [35] reported that heavily contaminated brownfield lands are less attractive to developers for residential housing compared to lightly contaminated lands. Unfortunately, the national land use database and published local authority brownfield land registers are devoid of information on the presence and type of contamination on brownfield land [5].

2.2.4. Site Size

Brownfield sites vary in size, which is a critical factor considered in site selection for remediation, as developers are interested in either small or large sites depending on their investment plans. From the point of view of local authority plans, the standard average housing capacity recommended for redeveloped brownfield land is 40 dwelling per hectare with flexibility for higher or lower housing capacity depending on the location of the brownfield site [36]. At central towns and city locations near to public transport hubs, higher densities of housing units are encouraged, while in suburbs and rural areas, housing densities may be lower per hectare. This explains the reasons for varied interest of developers in the size and capacity of brownfield sites. Evidence from Longo and Campbell (2017) [5] showed that large sites with histories of industrial uses and located in the poorest and deprived areas are considered difficult to redevelop by developers. Although the brownfield land register regulation 2017 stated that brownfield land having a minimum size of 0.25 hectares or the capability of accommodating at least five dwellings can feature on the part 1 of the local authority’s brownfield land register, evidence from recent studies has shown that many small sites are being excluded from published local authority’s brownfield land registers. According to CPRE (2021) [3], “The amount of brownfield land identified on brownfield land registers is likely not exhaustive. Previous research suggested that many sites are being left off registers, particularly those that are smaller”. The study cited a typical case study of 40 brownfield sites (covering 72 hectares of brownfield land with the capacity to provide over 1000 homes) that were missing from brownfield land registers of the Lancashire local authority in 2019 until the sites were discovered through the pilot implementation of the Brownfield Land Register Toolkit developed by CPRE.

2.2.5. Future Land Use

In the context of brownfield redevelopment, the term “future land use” refers to the type of development that a brownfield site can be used for after remediation. The types of development permitted on a parcel of brownfield land are usually indicated in the local authority brownfield register. A remediated brownfield site could be used for residential, employment spaces, parks, etc. “Future land use” is a key criterion that drives the choice of brownfield site for redevelopment; stakeholders involved in remediation and redevelopment of brownfields are usually keen to have knowledge of the kind of planning permission that is available for the future land use of a brownfield site prior to acquisition. Furthermore, the sensitivity of the future use of brownfield land (please refer to

Table 1. Sensitivity of end use of brownfield site and potential remediation cost [28].

Type of Future Use	Health and Safety Sensitivity	Potential Remediation Cost Depending on the Site’s Previous Use Category
Commercial with soft landscaping (e.g., business parks)	Low sensitivity	GBP 50 K to 665 K
Public open space; residential without private gardens; universities and colleges	Moderate sensitivity	GBP 50 k to 740 K
Residential with private gardens; nursery and primary schools with pitches and playground; farming allotments	High sensitivity	GBP 75 K to 845 K

) determines the intensity of remediation that must be carried out on the land, which means that remediation cost may vary based on the type of end use [28]. As such, future land use is one of the key factors that developers consider when making decisions to redevelop brownfield land. As shown in Table 1, future use of brownfields for residential purposes falls in the category of medium to highly sensitive end use, and the higher the sensitivity, the higher the remediation cost.

2.2.6. Land Ownership

Brownfield lands are owned privately, owned by the local council, or have unknown ownership status. Research studies have shown that of the 17,982 individual brownfield sites published in 300 brownfield site registers of local authorities in the UK, 12% are publicly owned, 61.5% are privately owned, and 22.4% have unknown ownership status [37]. Developers are often keen to know the ownership status of brownfield land before making decisions on redevelopment because, based on the principle of “polluter pays”, the legal owner of brownfield land is a key stakeholder when it comes to allocating liability for clean-up/remediation should contamination be detected during the environmental assessment stage. Green (2018) [24] pointed out that lack of clear and correct information about the ownership of brownfield land may complicate the process of allocating site cleanup liability, although as part of efforts to encourage redevelopment of brownfield sites there are some funding programs and incentives in place for brownfield remediation. Sometimes the liability for cleaning up a brownfield site lies with the party responsible for the contamination, and the new owners, in this case the developers, are free from liability [32]. However, there are various concerns regarding clean-up liability that often make developers hesitate to participate in brownfield redevelopment. Based on a legal perspective published by [38,39], the liability for remediating/cleaning up a site may shift to the developer if the contamination becomes discovered only after the purchase has been completed, or if it was discovered during the process of development. Further, the liability for remediating contamination may also shift to the owners of the newly built properties if the developer has ceased to trade/exit after the new home is purchased. It should be noted that despite the benefits associated with publicly owned brownfield lands compared to privately own brownfields, a study by Long and Campbell (2017) [5], which used a choice model supported by GIS data to analyse the national land use database (a register containing over 21,000 English brownfields), showed that in England, the potential for redeveloping privately own brownfield land is 8.5% higher than for publicly owned brownfield lands.

The overall consensus from the literature is that depending on an individual developer’s needs, the various criteria that aid decisions for regenerating brownfield sites could serve as the drivers encouraging the uptake of brownfield lands for redevelopment or could serve as tension, dissuading developers from redeveloping brownfield sites. However, the theme that is most common among the studies reviewed is that knowledge of factors including remediation cost, contamination level, site size, funding, and land ownership, amongst others, is important to encourage the increased uptake of brownfield lands for redevelopment. For example, brownfield remediation costs which can be up to GBP 100 K per acre, represent a key component of the potential budget for redevelopment. The contamination level of brownfields often presents concerns relating to environmental compliance, financial risk, expensive engineering clean up, liability issues, and neighbourhood opposition, and brownfield site size determines the housing unity capacity of the site and indirectly dictates potential returns on redevelopment. Future land use determines the sensitivity of the end use of brownfield sites and potential remediation costs, while land ownership dictates the clean-up liability and availability of funding and incentives, which have the potential to facilitate less expensive clean-up costs and often enable developers to make informed decisions on brownfield redevelopments. The next section will discuss the adopted methodology for this study.

3. Methodology

This study adopted a mixed methodology employing qualitative and quantitative research methods including a review of the state-of-the-art literature and interviews with experts and stakeholders to investigate the factors that developers look for when considering brownfield regeneration.

The literature review for this study was conducted using the narrative review approach in accordance with the stepwise procedure reported by Demir et al. (2019) [40]. Various databases were searched for studies on the subject of “criteria/factors that aid developers” decisions on brownfield regeneration and redevelopment: Key search terms included brownfield lands characteristics; brownfield regeneration process; brownfield redevelopment criteria; brownfield register; predictors and determinant of brownfield redevelopment; developers’ culture; brownfield regulations; brownfield remediation; etc. All literatures generated from the searches were thoroughly examined, and the most relevant articles (published between 2004 and 2022), on the subject of interest were selected for review and in-text citations and reference list provided to acknowledge sources and years of publication.

Thematic analysis and deductive coding of the interview data were conducted using NVivo 12 Pro. Leveraging the findings obtained from the literature review and the interviews data, phyton programming in conjunction with data from relevant databases was used to develop the criteria-based brownfield indexing software, namely, the BRIC Index. For the literature review, relevant information was obtained from various databases, sources, peer reviewed journal papers, and conference proceedings on brownfield regeneration and redevelopment. The literature sources used for the review included literatures and reports published on the subject between 2011 and 2022. A total of 11 stakeholders involved in brownfield redevelopment, planning, and remediation in England was interviewed to find out what factors they look for when considering redevelopment of brownfield land.

Brownfield stakeholders are those who may be directly or indirectly affected by brownfield development decisions. Hence, the scope of people eligible to be regarded as a stakeholder is wide and based on experience and involvement; these stakeholders often hold insightful perspective on matters relating to brownfield uptake and development. Hou (2016) [41,42] as well as Hou et al. (2014) [43,44] reported that the five types of stakeholders in influencing the adoption [43] of sustainable brownfield remediation are primary stakeholders, institutional field actors, intra-organization stakeholders, local community interests, and other working parties. The stakeholders regarded as primary stakeholders cover site owners and managers, regulators, and primary consultants, and institutional field actor stakeholders are competitors, professional organisations, and academia. Hence, our purposeful sampling of stakeholders cut across the various categories of brownfield stakeholders reported in the literature.

A total of 11 brownfield stakeholders that cut across key experts involved in brownfield redevelopment within the Black Country region of England was interviewed. Each participant interviewed holds a critical role in regulatory organisations and construction industry organisations, including local authorities, geo-environmental organisations, land remediators and consultants, housing developers, etc.

Table 2. Detailed characteristics of interviewed participants.

Participants	Organisation/Area of Employment	Participant’s Stakeholder Role
R1	Land remediation	Land remediator (director)
R2	Local government official—coal mining data	Commercial products manager
R3	Ground survey company	Geo-environmental scientist
R4	Local authority (council)—planner	Lead planning manager
R5	Geo-environment consultant	Consultant
R6	Land remediator	Senior contaminated land specialist
R7	Environmental or geo-environmental engineer	Contractor
R8	Brownfield bio-remediation contractor	Director
R9	Economic place-based intelligence (planning)	Researcher/analyst
R10	Economic and urban regeneration	Economic and urban regeneration specialist
R11	Project manager and geologist	Manager of geo-environmental team; project manager; senior engineer and designer on projects

shows the demographic characteristics of the participants interviewed. The number of participants interviewed from different organisation is presented in Figure 1. As shown in Figure 1, 3 participants work in land remediation organisations, 1 participant works as a local government official, 2 participants work in geo-environmental organisations, 2 participants work as planners, 1 participant works as a consultant, 1 participant works as an economic and urban regeneration specialist, and 1 participant works as a project manager and geologist.

4. Results and Discussion

The first part of this section details the findings from the interviewed participants about the factors that developers look for when considering brownfield redevelopment. The later part of this section provides a brief description of the BRIC Index, which was developed incorporating the factors identified based on the findings obtained from the interviewees and the literature review.

4.1. Stakeholders Responses on Factors That Developers Look for when Considering Brownfield Redevelopment

Table 3. Stakeholder responses on factors and criteria that developers look for when considering brownfield regeneration.

Factors Developers Look for When Considering Brownfield Redevelopment	Frequency	Interviewed Stakeholders Who Indicated the Factors
Previous land use	8	R1, R2, R6, R5, R7, R8, R10, R11
Price/capital expenditure	5	R1, R6, R5, R7, R8
Future land use	5	R7, R8, R10, R11, R5
Planning permission/planning status	9	R7, R8, R9, R10, R11, R3, R1, R4, R5
Access and connectivity/access/site accessibility	8	R7, R8, R9, R10, R11, R1, R3, R4
Size and density	3	R1, R4, R10
Water risk/flood risk	5	R7, R8, R10, R11, R3, R5
Natural ground conditions	3	R3, R6, R5
Infrastructural development	8	R7, R8, R9, R10, R11, R1, R3, R4
Environmental permits	3	R1, R6, R5
Geographic location	5	R1, R3, R6, R4, R8
Neighbours/receptors	7	R1, R3, R6, R5, R7, R8, R10, R11
Market attractiveness	4	R4, R8, R10, R11
Contamination level	1	R8
Land ownership/availability	1	R4
Current site status and site layout	1	R4

presents 16 factors identified by the interviewed participants as the criteria for redeveloping brownfield sites; clearly, some of these factors identified including site size, contamination level, capital expenditure/cost, land ownership, and future land use agree with the range of factors identified from the reviewed literatures. As such, Section 4.1.1, Section 4.1.2, Section 4.1.3, Section 4.1.4, Section 4.1.5, Section 4.1.6, Section 4.1.7, Section 4.1.8, Section 4.1.9, Section 4.1.10 and Section 4.1.11 discuss further criteria identified by interviewed participants that are different from those already discussed in the literature review section.

4.1.1. Previous Land Use

Previous land use refers to the type of development that had taken place on a brownfield site since first acquired. The knowledge of previous land use often helps to categorize brownfield lands based on their historic development since the 1880s. As presented in Table 3, many participants (R1, R2, R6, R5, R7, R8, R10, R11) agreed that previous land use is a key factor in selecting brownfield sites for development. At land remediation organisations such as the one in which the participant (R1) is currently practicing as a land remediator, brownfield sites to be remediated are usually categorised into (a) industrial park, (b) general manufacturing, (c) high-tech manufacturing, and (d) warehouse or distribution, based on the type of industry previously built on the site. Participant R6, a senior contaminated land specialist believes that “landfill sites” are another important category that should be added into previous land use classification because landfill sites are riskier if they were assigned before 1974 when a waste regulation act was introduced to address landfill contamination.

Based on the opinion that previous land uses can have impacts on groundwater contamination and on neighbouring sites and/or communities, participant (R2), whose organisation holds coal mining data and provides licensing towards cold mining in Britain, suggested and stated that “a thorough analysis should be added towards previous land use by considering data such as coal mining, bombs from WWII and additional information gained from various sources such as British Geological Survey (BGS) about land, What’s in Your Backyard, archives etc. This will help in getting information about the site and add values towards preliminary investigation”.

Participant (R5), a geo-environment consultant, advised that historic data showing the previous use of a brownfield needs to depend on historic data that can be obtained from archives or digital historic mapping such as Digi Map; radon gas emission areas mapping, which will have potential vapour issues; groundwater data from utility maps; and air quality analysis from environmental agency data. According to (R5) “previous land use information needs to verify whether the site was pond or ground. If it was pond, was it filled with sand or anything else”.

4.1.2. Price/Capital Expenditure

Price/capital expenditure is the cost allocated to land remediation and building demolition or refurbishment of existing buildings on a brownfield site. This also includes costs of land or its availability for lease. The cost of redeveloping a brownfield may be either low or high. Some participants (R1, R6, R5, R7, R8) revealed that the price, costs, and capital expenditures of redeveloping a brownfield site are important criteria in site selection, and that funding likelihood could encourage the choices made. According to participant (R1), “the target of Land remediation organisation is to buy lowest capex-to-land use ratio. This helps towards their business model by acquiring highly contaminated site with cheap cost and sell it with minimum contaminations at certain profit margin” (R1).

To ensure detailed cost estimation, Participant (R6) said that “there is need for more detailed information than the abstract cost estimation for site remediation. Factors that need to be considered in brownfield redevelopment costing are: (a) site value; (b) site size; (c) current problem to the site; (d) grid-to-grid site estimation of cost; (e) waste disposal charging; (f) soil remediation technique cost; (e) groundwater remediation technique cost”. Furthermore, participant (R5) added that brownfield redevelopment costs need to be linked with ground conditions, as values will be different, and that contamination filtration testing can be added to the cost (R5).

4.1.3. Planning Permission/Planning Status

As shown in Table 3, many participants agreed that the planning status of a brownfield site is a key determinant in selecting a site for redevelopment. In terms of planning status, brownfield sites on the local authority brownfield register may be divided into three categories, including (a) sites that have no planning permissions, (b) sites that have outlined permissions, and (c) sites that have full planning permission. Participant (R4) revealed that at the local authority, “the planning status of brownfield site (and its classification on the basis of most preferred (‘5’) to least preferred (‘1’)) may include (a) detailed planning permission (classified as ‘5’), (b) outline planning permission (classified as ‘4’), (c) published development brief (are classified as ‘3’), (d) allocated/protected in local plan (classified as ‘2’), (e) allocation in deposit draft local plan, or reserve site (classified as ‘1’). If a brownfield site has detail planning status, then waiting time will be reduced” (R4). Similarly, participant (R5) pointed out that it is good practice to undertake an analysis of the previous planning held for a brownfield site in order to find out any existing conditions of planning, restrictions on drains, etc. (R5).

4.1.4. Access and Connectivity/Access/Site Accessibility

The accessibility of a brownfield site pertains to the existence of connectivity to the site from the local town centre and motorways, and ease in accessing the site. Major considerations for accessibility include road access to the site and site distance from the local town centre, canals, and motorways. According to participant (R1), the existence of road access to a brownfield site is a major benefit, as heavy vehicles need to gain access to the site, and secondly, nearness of the motorway is another major benefit (R1). Participant (R4) revealed that local authorities mainly focus on future development, and the main focus is in bringing housing or commercial development to areas where roads and cyclist or pedestrian infrastructure is already developed. According to participant (R4), in terms of public transport access, brownfield sites can be ranked as follows:

• Close to a station, peak time bus route and cycle route; on a pedestrian route (are weighted “5”),
• Close to a station or peak time bus route, close to cycle route, on a pedestrian route (are weighted “4”),
• Close to either a station or peak time bus route or cycle route or a pedestrian route (are weighted “3”),
• Not near a station, peak time bus route or cycle route or a pedestrian route (are weighted “2”),
• Not a pedestrian route, not near a station, peak time bus route or cycle route (are weighted “1”).

Participant (R3) added that canals are not needed for access to brownfield sites because major transportation used currently through road site access for HGVs is critical. The same participant (R3) warned that traffic can be halted while remediation is ongoing.

4.1.5. Water Risk/Flood Risk

If the potentially contaminated site is in an area where there are sensitive water receptors on, adjacent to, or under the land, then it may be necessary to perform additional remediation. As shown in

Table 4. Categories of brownfield sites’ water and flood risks.

Low

High

Aquifer protected by a significant thickness of cohesive strata that will not be breached during construction or where appropriate control can mitigate the breach. Unproductive strata, perched water in made ground, or secondary aquifer in low sensitivity environment. No surface water or no linked surface water within 250 m of the site. Canalised river or canal or dock not directly linked to groundwater.

Source protection zones 1 and 2 on site associated with a sensitive water abstraction either on or close to the site. The aquifer is not protected by a significant thickness of cohesive soil. Shallow principal aquifer not protected and having certain types of local abstraction closer than 250 m. Sensitive surface water on or close to the site and linked by shallow aquifer. Shallow (unprotected) secondary aquifer on site. Preferential pathways that could result in the rapid migration of contamination, either lateral or to depth (for instance to deeper aquifer).

, brownfield sites can have either low water risks or high water risks. Interviewed participants from organisations including a ground survey company, a geo-environment contractor/consultant, a brownfield bio-remediation contractor, and an economic and urban regeneration specialist expressed concerns for water risk/flood risk at brownfield sites and agreed that it is a key criterion for their choice of brownfield site for development. Participant (R3) emphasized that water risk from floods or canals can be an issue, and participant (R5) advised that water analysis is required to quantify any risk to the site for future development. Relevant information can be obtained from the Environment Agency: “What’s in Your Backyard?” (maps and data) website.

4.1.6. Infrastructural Development

Since most brownfield sites are located near or within built-up areas, infrastructures such as main power lines, communication networks, and drainage may be present at or near the site premises. The existence of infrastructures like this may be beneficial to the site for further development. Participant (R1) explained that infrastructure already installed at brownfield sites is advantageous and could include main power lines, drainage, and communications network. However, participant (R3) warned that existing “infrastructural development at brownfield could be a constraint instead of benefits, this is because, if the site is a power station, then it has huge number of cables which in itself is a major issue to sort” (R3). According to participant (R4), sites that are closer to local services are better. On a rating scale of 5 to 1 (the higher the better), brownfield sites (a) close to a town centre with five or more ranges of services are rated 5, (b) close to a local centre with four different ranges of services are rated 4, (c) close to three different ranges of basic services are rated 3, (d) close to one or two services are rated 2, and (e) those with no services in close proximity are rated 1.

4.1.7. Geographic Location

Depending on the distance from an urban centre, brownfield sites may be classified into rural/peri-urban, suburban, and inner city/urban. A brownfield site will be regarded as rural/peri-urban if it is located more than 5 miles from an urban centre. Sub-urban brownfield sites are those located within 2 to 4 miles from an urban centre, and inner city/urban brownfield sites are those located within two miles from the urban centre. The location of a brownfield site and the characteristics of the location (including rural, urban, commercial, residential, industrial, traffic, access, proximity to waste market, residential) are of utmost importance to developers when making decisions for redevelopment, although the concerns and interests of stakeholders on characteristics associated with a brownfield location vary depending on their area of employment and stakeholder role in brownfield redevelopment. For example, participant R1 explained that his organisation is often highly interested in remediating brownfield sites that are located in urban and industrial area with good access to the waste market. R1 further stated that “High contamination is obtained from heavy industrial sites, so, the ideal for our organisation is to get site which is in industrial location and additional benefit will be achieved if the site has good access to waste market”.

Other site location concerns expressed by participants included traffic and site history. Participant R3 said that “traffic can be halted while remediation is ongoing”, and participant R6 indicated that “historic landscape may lead towards conservation areas”.

Furthermore, the strategic location of a brownfield site is one of the factors used in prioritising sites at local authorities. Participant R4 indicated that “The various strategic location of brownfield site (and their ratings on the scale of the higher the better) may include (a) motorway corridor (rated as 5), (b) other strategic roads (rated as 4), (c) sub-regional centres (rated as 3), (d) other towns (rated as 2), (e) all other sites (rated as 1). Strategic location development is always the first priority because detailed analysis is already carried out for its development” (R4).

At local authorities, brownfield sites are ranked based on the character of the area of location. According to participant R4, “brownfield sites located in (a) well established commercial area (ranks as 5), (b) established commercial area, with residential area or rural area nearby (ranks as 4), (c) mixed commercial and residential area (ranks as 3), (d) mainly residential or rural area with few commercial uses (ranks as 2), (e) mainly residential or rural area with no existing commercial uses (ranks as 1). As such, at local authorities, brownfield sites located in commercial areas is superior to those located in residential area”.

Furthermore, sites having prominent views have high demand, on a scale from 1 to 5, where a higher number is better: (a) a gateway site to a prominent estate, visible from a major road network (ranked 5), (b) a visible site on a main road or prominent estate (ranked 4), (c) on a main road or prominent estate tucked away from view (ranked 3), (d) visible, on a minor road or estate (ranked 2), and (e) on a minor road or estate, tucked away from view (ranked 1) (R4).

4.1.8. Neighbours/Receptors

The features and developments around a brownfield site are a key consideration in site selection for redevelopment because the approach adopted for remediating the site will impact the neighbourhood. Many interview participants (R1, R3, R6, R5, R7, R8, R10, R11) stated that neighbourhood is a key criterion in their decision to redevelop a brownfield site. According to many interview participants, the sensitivity of a neighbourhood of a brownfield site is based on its location; remote and industrial area are regarded as low sensitive neighbourhoods, moderately sensitive neighbourhoods are commercial and retail areas, while highly sensitive neighbourhoods cover housing and residential areas.

Some of the impacts that remediation could cause for the neighbourhood of a brownfield site include air pollution, noise pollution, the spread of contamination through air (fumes) or groundwater, etc. Participant (R1) said that “air pollution and noise impact the neighbourhood, and this can cause issue towards limitation or stoppage of work”. On a similar note, participant R3 added that “Noise has direct impact on neighbourhood” (R3). In terms of adjacent site impact, participant R6 expressed the view that off-site contamination can impact the selected site because the spread of contaminants usually impacts the neighbourhood via different pathways such as air (fumes) or groundwater (R6). On a different note, participant R5 said that objections of neighbours to the development need to be added to the criteria for redeveloping a brownfield site, and road cross works analysis and requirements are important (R5).

4.1.9. Environmental Permit

The acquisition of an environmental permit is a mandatory requirement prior to progressing the regeneration of a brownfield site. The permit usually sets out the limit for permissible/non-permissible pollution from the site and what must be done to prevent and control them in accordance with Environmental Permit Regulation 2016. The time and cost of remediating a brownfields site can be reduced if the site already has existing permits; otherwise, an environmental permit must be acquired from the local authority. Some of the information that may be of interest to developers with regards to environmental permits includes the history of permits for waste removal from the site and the existing permit and waste management. Participant (R1) explained that a history of waste permits makes it easier to work on a brownfield site; hence, the existence of an environmental permit becomes ideal in site selection (R1). Citing an example, participant (R6) said that “In terms of exploded bomb data, high risk bomb maps need to be considered, as that is crucial to safety”. Both participants (R5) and (R6) warned that due diligence should be observed to ensure appropriate steps to avoid legal actions that may originate from risk to neighbours if a brownfield site is redeveloped or remediated. According to participant (R1), “developers should analyse in detail what type of permits the site already has for remediation along with their resource. Do the sites have pathways and sideways permits? Landmark for permits needs to be checked as well. This is required for safety issues. It can be obtained from various sources”.

4.1.10. Current Site Status and Site Layout

The status of brownfield land could be empty, partially built, or fully built at the time of consideration for redevelopment. The status of a brownfield site often allows land developers to choose the best site, which depends largely on the previous land use history of the site. Participant (R4), a local authority lead planning manager, explained that in terms of site layout, a brownfield site can present as a (a) clear plot, no obstructions (rated as “5”, being the most preferred), (b) regular-shaped plot, obstructed (rated as “4”), (c) regular-shaped plot, fragmented (rated as “3”), (d) irregular-shaped plot, obstructed (rated as “2”), and (e) irregular-shaped plot, fragmented (rated as “1”, being the least preferred), on a scale of the higher the better. According to R4 “Sites with regular shape are easy to develop, and land developers are interested in such sites. The land values of such sites are higher as well”.

A review of the interview findings, as discussed in preceding sections, revealed several factors that developers of brownfield sites consider important that are not covered extensively in the literature. Having understood these developer requirements, the succeeding section critically reviews the effectiveness of brownfield land registers maintained by local authorities in meeting those requirements.

4.1.11. Natural Ground Conditions

Brownfield sites may present constraints relating to natural ground conditions such as the topography/geology of the site, presence of canals, groundwater sensitivity, etc. In terms of ecology, landscape and ecology are important to consider (R3). In terms of groundwater sensitivity, participant R6 explained that contaminations may impact groundwater, which may lead to contamination spread. Participant R6 recommended that groundwater aqueous status may be checked via the environmental agency (R6). According to participant R5 “data needs to be obtained from BGS, land authorities and environmental agencies to identify ground conditions. Current site issues are the most important category and needs to be analysed based upon ecology. It is applicable mostly on remote or rural sites. Furthermore, tree survey analysis is sometimes required, and it is seasonal. Moreover, primary ecological survey causes delays sometimes due to seasonal effect. Secondly Japanese knotweed analysis is required” (R5).

4.2. Effectiveness of Brownfield Land Registers in Meeting Developers’ Requirements

This section provides a critical appraisal of the local authority brownfield registers relative to the information needs of developers in making decisions for brownfield regeneration.

4.2.1. What Is the Brownfield Land Register?

The Brownfield Land Register is a list containing all brownfield lands that are suitable for housing development at individual local authority areas in the UK. The preparation and implementation of the brownfield land register was brought about by the requirements of the UK Housing and Planning Act 2016 and the Brownfield Land Register Regulations 2017, which mandated all local authorities in the UK to prepare and publish a comprehensive list of brownfield lands located in their local authorities [45]. The essence of the brownfield land register is to ensure that house builders can quickly, easily, and speedily identify suitable brownfield sites for the construction of new homes [45,46]. According to Charlson (2021) [47], “The majority of brownfield land registers have been successfully published”, and as of 2021, there were 338 published local authority brownfield registers that identify over 18,200 brownfield sites covering over 26,000 hectares. Part 1 of the brownfield land register usually contains brownfield sites categorised as previously developed land, which meets the criteria of suitability, availability, and achievability for residential development, as shown in

Table 5. Criteria and minimum requirement for sites listed on Part 1 of the brownfield land register.

Criteria/Characteristics of Site Listed on Part 1 of Brownfield Land Register	Minimum Requirement
Previously developed	Previously occupied by a permanent structure, and any associated fixed surface infrastructure
Size	A minimum of 0.25 hectares or be capable of accommodating at least 5 dwellings
Suitable	Sites must be appropriate for residential use or a residential-led mixed use scheme, and must comply with national and local planning policies
Available	There must be verifiable evidence of landowner or developer’s intention to sell or develop the site
Achievable	Sites must be developable within the next 15 years

. Part 2 contains sites selected (from Part 1 by the local authority planning) and granted permission in principle for housing-led development. According to Schedule 2 of the Town and Country Planning (Brownfield Land Register) Regulations 2017, the individual local authority’s brownfield land register should feature information including site reference, site name and address, site plan URL, coordinates and geographic location, size, ownership status, deliverability, planning status and permission type, planning history, minimum net dwelling, development type, and date entered on the register.

4.2.2. Has the Brownfield Land Register Been Effective in Meeting Developers’ Information Needs?

As shown in

Table 6. Has the brownfield land register been effective in meeting developers’ information needs?

Determinants of Brownfield Land Redevelopment	Factors that Housing Developers Consider in Selecting Brownfield Sites for Redevelopment	Information Available in a Standard Brownfield Land Register
Cost/capital expenses	✓	☒
Funding	✓	☒
Contamination level	✓	☒
Site size	✓	✓
Future land use	✓	✓
Land ownership/ownership status	✓	✓
Infrastructure	✓	☒
Previous land use	✓	✓
Planning status	✓	✓
Water risk	✓	☒
Neighbours	✓	☒
Location	✓	✓
Connectivity (digital, energy networks/grid)	✓	☒
Access and transport	✓	☒

✓ indicate ‘YES’; ☒ indicate ‘NO’.

, the information available in a standard brownfield land register is clearly not sufficient to enable developers (and other relevant stakeholders) to make an informed decision or to assess the potential risks associated with redevelopment of a typical brownfield site during the site selection stage. Based on the findings of this study, the comparison presented in Table 6 shows that 57% of factors that housing developers consider in selecting brownfield sites for redevelopment (which represents some key information required to make an informed decision) are not available on the local authority’s brownfield land registers.

This limited effectiveness of the brownfield land registers in meeting housing developers’ information requirements explains some of the reasons that many available brownfield lands have remained undeveloped. This finding agrees with the findings reported by previous studies [3,11,47], which indicated that despite the 18,000 brownfield sites that have been mapped with a capacity for 1.3 million homes on 21,000 sites covering 25,000 hectares identified, the lack of accurate data on brownfield land and local planning provision have been barriers/obstacles for new and small and medium-sized construction firms in redeveloping brownfield lands.

Whilst the brownfield registers of local planning authorities (LPAs) often contain lists of all developable brownfield sites within a local authority, studies [3,11,47] have shown that many of the published registers usually feature limited information about the listed brownfield sites. The information available within LPA brownfield registers include information on area, estimated minimum housing capacity, ownership, planning status, and timeline for site deliverability. As such, housing developers often struggle or incur additional expenses to obtain information on vital criteria (such as contamination level) for informed decision-making during consideration for brownfield redevelopment. In addition, CPRE (2021) [3] indicated that brownfield land registers published by the majority of local authorities in England are associated with limitations including complicated accessibility, non-transparent and less-frequently updated information on brownfield lands, inconsistent and inaccurate data, and obsolete/altered templates.

To address these challenges, the Brownfield Research and Innovation Centre (BRIC) has developed a tool, namely, the BRIC Index, to enable SMEs to utilise a specified set of search criteria to find, compare, and identify suitable brownfield site across the Black Country (comprising metropolitan district council areas including Wolverhampton, Walsall, Dudley, and Sandwell) based on statistical analysis.

4.3. The BRIC Index

The BRIC Index is a dynamic decision-making tool that utilises statistical analysis to identify brownfield sites based on a set of customer/developer-supplied search criteria, which are then ranked in line with the customer’s requirements. As an improvement over the brownfield land register, the BRIC Index leveraged the evidence obtained from stakeholders interview responses and from the literature to incorporate (1) factors, criteria, and key information that developers need and look for in redeveloping brownfield sites, (2) estimated remediation costs in accordance with Homes England guidelines and HCA guidelines, and (3) a GIS-based system that facilitates the screening of brownfield sites depending on the precedence of specified factors. As per criteria and factors that aid brownfield redevelopment decisions, the literature revealed factors including remediation costs, funding, contamination level, site size, future land use, and land ownership, amongst others, and the interviewed participants-mentioned factors including previous land use, price/capital expenditures, future land use, planning status, access and connectivity, size and density, water risk/flood risk, natural ground conditions, infrastructural development, environmental permits, current site status and site layout, geographic location, and neighbours/receptors. Hence, the factors obtained from both the literature and BRIC Index incorporates eleven factors, namely, site size, future land use, land ownership, previous land use, remediation cost range, planning status, access and connectivity, water risk/flood risk, infrastructural development, geographic location, and neighbours/receptors, which comprise a summary of the factors merged from both the literature and interviews (see

Table 7. Criteria and factors that aid brownfield redevelopment decisions—Emergence factors used for BRIC Index.

Factors Revealed by Literature Review	Factors Revealed by Interview Participants	Emergence Factors Used for BRIC Index
Remediation cost	Previous land use	Site size
Funding	Price/capital expenditure	Future land use
Contamination level	Future land use	Land ownership
Site size	Planning status	Previous land use
Future land use	Access and connectivity	Remediation cost range
Land ownership	Size and density	Planning status
	Water risk/flood risk	Access and connectivity
	Natural ground conditions	Water risk/flood risk
	Infrastructural development	Infrastructural development
	Environmental permits	Geographic location
	Current site status and site layout	Neighbours/receptor
	Geographic location
	Neighbours/receptors

). Furthermore, the factors used in the BRIC Index were further classified into sub-categories, as shown in

Table 8. Criteria definition with sub-criteria.

Criteria	Definition	Sub-Criteria
Present status	Land current status	Built: Site already built and come under brownfield land.
		Empty land: Site completely vacant and come under brownfield land.
		Partially built: Site partially built and come under brownfield land.
Previous land use	Land discrimination based upon historic development on site since 1880s	Site category A: Small scale and general industrial sites, colliery or mine spoil heaps, miscellaneous factories and “works” (not heavy industry), sites with very small to small fuel tanks.
		Site category B: Garages, workshops, pithead sites, railway lines, textiles, small scale timber treatment, sewage works, smaller chemical works, sites with small to mid-sized fuel tanks.
		Site category C: Metal workings, scrap yards, and shipyards. Paints and solvents, small gasworks/gas holder sites, smaller power stations, rail depots (maintenance and refuelling), sites with large fuel tanks.
		Site category D: Major gasworks, iron and steel works, large chemical works, refineries and major fuel depots, ship breaking and building, larger power stations, sites with large tank farms.
Future land use	What will be built on the site once it is remediated	Low: Employment or commercial with limited soft landscaping, business parks and data centres.
		Moderate: Public open space. Residential without private gardens (flats and apartments), universities and colleges.
		High: Residential with private gardens. Schools for younger children with pitches and play areas. Allotments and growing areas in developments.
Water Risk	If the potentially contaminated site is in an area where there is sensitive water receptors on, adjacent to, or under the land, then it may be necessary to perform additional remediation	Low: Aquifer protected by a significant thickness of cohesive strata that will not be breached during construction or where appropriate control can mitigate the breach. Unproductive strata, perched water in made ground, or secondary aquifer in low sensitivity environment. No surface water or no linked surface water within 250 m of the site. Canalised river or canal or dock not directly linked to groundwater.
		High: Source protection zones 1 and 2 on site associated with a sensitive water abstraction either on or close to the site. The aquifer is not protected by a significant thickness of cohesive soil. Shallow principal aquifer (unprotected) that has some form of local abstraction (closer than 250 m). Sensitive surface water on or close to the site and linked by shallow aquifer. Shallow (unprotected) secondary aquifer on site. Preferential pathways that could result in the rapid migration of contamination, either lateral or to depth (for instance to deeper aquifer).
Geographic location	Distance from urban centre (ease of access to the site)	High: (Rural/peri-urban) more than 5 miles
		Moderate: (Suburban) 2–5 miles
		Low: (Inner city/urban) within 2 miles
Access (connectivity)	Site access (Y or N) Closeness to motorway (more or less than 5 miles) Closeness to town centre (more or less than 2 miles)	Low: No site access; more than 5 miles from the motorway, more than 2 miles from a town centre
		Moderate: In-between
		High: Site access; less than 5 miles from the motorway, less than 2 miles from a town centre
Neighbours	What is around a site and how will remediation be impacted	Low sensitivity: Remote/industrial
		Moderate sensitivity: Commercial/retail
		High sensitivity: Housing/accommodation
Infrastructure	Presence of drainage systems, electricity, and other utilities around the site that would impact connectivity	Low: No infrastructure
		Moderate: Some infrastructure
		Good: Well developed infrastructure
Planning permission	Permission to build/modify on the site	No planning permission
		Outline planning permission
		Full planning permission

.

As a result, the BRIC Index has the capability to show brownfield sites available in the Black Country that meet developers’ requirements, and its effectiveness has been validated through numerous successful usages for site selection by various SMEs in the Black Country.

How Can the BRIC Index Help Developers?

Decision-making tools are integral in brownfield redevelopment to help identify risks, contamination, and remediation costs. The effectiveness of these tools is dependent on human choice and their previous experience of involvement in key decisions; for example, whilst brownfield remediators are usually interested in remediating highly contaminated brownfield lands, developers are keen on securing brownfield sites with minimal contamination levels given the health- and safety-related sensitivity of the end use of the brownfield site and the potential risk to neighbourhood infrastructure and receptors. BRIC has developed a tool to address the current key challenges faced by SMEs in selecting a brownfield site. The BRIC Index can help remediation stakeholders and developers to carry out the following:

• Find the most suitable brownfield site across Black Country based on statistical analysis using a specified set of search criteria.
• Compare and prioritise the identified sites based on the scores obtained.
• Analyse the preferred individual site(s) using the BRIC database.
• Estimate a cost range to remediate the selected brownfield site(s).

In terms of structure, the BRIC Index is comprised of four sections as illustrated in the BRIC Index dashboard shown Figure 2. Section one of the BRIC Index, designated as “Region”, allows all or a choice of local authority areas within the Black Country (such as Dudley, Walsall, Sandwell, and Wolverhampton) to be selected during a search for brownfield sites.

Section two of the BRIC Index, known as “Criteria”, consists of a list of criteria for brownfield site selection including site size, present status, previous land use, future land use, water risk, geographic location, access, neighbours, infrastructure, and planning permission. Each criterion is further classified into sub-criteria to allows developers to have various options. Section three of the BRIC Index consists of two sub-sections, namely, “Group” and “Criteria Definition”. The group sub-section includes the number of available matched sites from the total number of sites and further information on each of the matched sites. The list of information includes site reference, site address, its total score, and the cost range (cost range is explained in a latter section). Criteria Definition provides detailed information about criteria and sub-criteria.

Section four of the BRIC Index represents the data visualisation in terms of a map with data and statistical analysis-based generated data. All the sections are dynamically linked, which means if any region from section one is selected, the sites linked to that will be visualised on the map and analysed regionally. Similarly, sub-criteria selection from Section four allows for the filtering of sites and their visualisation on the maps. The same principle is used for Section three, whereby selecting a site from the group sub-section will present that site in maps of Section four. This section of the BRIC Index is comprised of four sub-sections, including Maps, Results, Database, and Cost Range. The Maps sub-section presents the data of matched brownfield sites data based on Sections 1–3, which are georeferenced. Furthermore, detailed information of each site can also be viewed by clicking on any site from the map. The subsequent sections provide brief descriptions of the Results, Database, and Cost Range tabs in the BRIC Index.

BRIC Index Results Tab

The Results tab in the BRIC Index represents the statistical results of matched sites, as shown in Figure 3. These results are obtained using the Analytical Hierarchy Process (AHP), a statistical method of producing weightings of each criterion and sub-criteria and to also create site-to-site comparison to generate optimum sites. The first pie chart stands for the percentage weighting for each criterion. The gauges represent the average weighting of each criterion based on matched sites. The bar charts represent the scores of each site generated from the site-to-site comparison. The bar charts are dynamic in nature, which means that if either bar from the bar chart is selected, then that site results for each criterion are shown, and that site will be shown on the map.

To decide which site is more appropriate for land developers, Multi-Criteria Decision Analysis (MCDA) procedures, which incorporate the well-known AHP methodologies [48,49,50], were used to statistically determine the weighting of each criterion and sub criteria. As shown in Figure 3, the AHP was used to identify the weighting of each site based upon a criteria-to-criteria comparison and a site-to-site comparison. The AHP procedure reported by [50,51,52,53] was adopted in this study to compute the weighting of each criterion and sub criterion and to arrive at the overall score for an individual site.

BRIC Index Database Tab

The BRIC Database tab comprises data from various sources, including all available brownfield sites in Black Country, historical digital data for an individual site, detailed site developments from 1800 across the Black Country, and borehole data sourced from the British Geological Survey (BGS). Each polygon on the map relates to different sources of information that can be viewed by clicking the shape; this is shown in Figure 4. Detailed site developments from 1800 across the Black Country and borehole data can be shown by switching on the layer add-on on the top right of the database sub-section.

BRIC Index Cost Range Tab

The BRIC Index Cost Range tab comprises a remediation of cost estimation for each site. The cost is estimated based on the calculations conducted by the Home and Community Agency 2015. The cost range is visualised using the map and is also dynamically connected with the criteria. The detailed information with regards to the remediation cost range in Pounds Sterling (£) can be viewed by clicking on a chosen brownfield site on the map (Figure 5).

Given all the features and capabilities described in Section 4.3, the BRIC Index is suitable for use by all businesses and other organisations associated with the ownership, use, and development of brownfield sites.

5. Conclusions

This study employed qualitative and quantitative research methods including a literature review of the state-of-the-art and interviews with experts and stakeholders to investigate the factors that developers look for when considering brownfield regeneration. Leveraging the findings obtained from the literature review and the interview responses, phyton programming in conjunction with data from relevant databases was used to develop criteria-based brownfield indexing software (designated as the BRIC Index). Based on the findings from this study, 57% of factors, criteria, and information that developers require for decision making relating to the redevelopment of brownfield sites are not available on a standard local authority’s brownfield land register. Brownfield land registers published by the majority of local authorities in England are associated with limitations including complicated accessibility, non-transparent and less-frequently updated information on brownfield lands, inconsistent and inaccurate data, and obsolete/altered templates. As an improvement over the brownfield land register, the BRIC Index incorporates (1) factors, criteria, and key information that developers need and look for in redeveloping brownfield sites, (2) estimated remediation costs in accordance with Homes England guidelines and HCA guidelines, and (3) a GIS-based system that facilitates the screening of brownfield sites depending on the precedence of specified factors. The BRIC Index has the capability to show brownfield sites available in the Black Country that meet developers’ requirements, and its effectiveness has been validated through numerous successful usages for site selection by various SMEs in the Black Country.