Residential Heritage Buildings in the Low Carbon Transition: Policy and Practice Challenges

Abstract

Residential heritage buildings (RHBs) are facing complex conservation challenges due to national policies aimed at achieving carbon emission reductions and associated retrofit recommendations. This long-term study (2007–ongoing) focuses on how such nationwide policies, particularly energy performance certificates (EPCs) and minimum energy efficiency standards (MEES), affect a cluster of 12 RHBs on the National Trust’s Wallington Estate in Northumberland, England. Data were collected using a combination of building measurements and survey observations, alongside assessment of tenant behaviours through an interview process. The research findings revealed a 53% average improvement in EPC ratings following a retrofit. However, the tenant interviews exposed some key limitations in current policy tools, including their failure to reflect actual energy use and behavioural patterns. For instance, despite improved EPC scores, some tenants reported high fuel costs and continued to experience heat loss and dampness in the RHBs. These novel findings of this longitudinal study challenge the suitability of current retrofit metrics and advocate for a people-centric and context-specific approach to energy efficiency in heritage buildings. They also highlight the drawback of proposed minimum EPC ‘C’ standards within the UK’s existing housing stock, particularly in relation to idiosyncratic RHBs.

1. Introduction

Climate change is the largest threat towards conserving residential heritage buildings (RHBs), specifically those constructed pre-1919, for future purposes [1]. With around 40% of the UK’s overall carbon footprint arising from the built environment [2], the UK government have implemented a swathe of policies aiming to address this global issue and shape a path to net zero [3]. One such response was the Climate Change Act 2008, which created a legally binding agenda for reducing greenhouse gas emissions and identified ‘research gaps’ in quantifying current and future risks to culturally valued structures and the wider historic built environment from climate change [4]. Energy performance certificates (EPCs) are a form of certification used to assess a property’s energy performance. They use a rating system ranging from A (most efficient) to G (least efficient) based on the estimated energy usage and running costs. Policies influence the preservation of RHBs, as demonstrated by the Energy Act 2011 legislation, which provided the framework for the now obsolete Green Deal policy and current minimum energy efficiency standards (MEES), which are still applicable within the private rented sector [5]. The MEES require all privately owned properties to meet at least an EPC rating of ‘E’ to be legally let, proposing to go up to a ‘C’ rating in future. Currently, limited studies examine the effectiveness of MEES regulations placed upon RHBs whilst considering the effect of tenant behaviour and the consequent impact upon heritage organisations, such as the National Trust, who need to manage the juxtaposition of RHBs delivering essential rental income to fund conservation with the need to not impede progress towards the organisational goal of net zero carbon. Ultimately, energy efficiency regulations created within the geopolitical macro-environment, such as MEES, impact the micro-environment of heritage organisations.

Whilst the UK Government’s Net Zero Strategy contains policies that focus on reducing the amount of carbon generated from the use of a property, MEES use measurements to produce EPCs based upon the estimated energy cost per m² through the standardised Reduced data Standard Assessment Procedure (RdSAP) modelling tool, which creates a conflict between two strategic aims. EPCs derived from the RdSAP often influence government policies and funded retrofit programmes, such as the Green Homes Grant [6] and Boiler Upgrade Scheme. At the local level, Northumberland County Council has declared a climate emergency and committed to indicating its efforts to achieve carbon neutrality for its operations by 2030 [7]. Its Climate Change Action Plan promotes retrofitting and renewable heating, yet specific guidance on moderating energy efficiency within heritage conservation—particularly in designated areas like Cambo (refer to Section 3)—remains limited. This creates challenges for implementing low-carbon measures in residential heritage buildings while adhering to planning constraints. Consequently, energy reduction within historic properties can be challenging to achieve due to limited retrofitting capabilities [5] and therefore fails to achieve carbon reduction goals [8]. As preservation means maintaining the integrity, identity, and functional efficiency of a cultural asset [9], multidisciplinary approaches are essential in order to improve active functionality and prevent further decay of built heritage assets due to climate change [10]. Whilst this paper provides the wider context of policies targeting carbon emission reductions when considering retrofit options, the implementation of mixed-methods research created a nomological link between the theoretical framework and the empirical framework of collected research data [11]. The findings highlighted the need to analyse the future impact of such policies upon RHBs, and this study assesses 12 case studies within the Trust’s care over a time period of over 10 years, evaluating data collected between 2007–2010 from a low carbon village (LCV) pilot scheme—a partnership project exploring low-carbon living through community engagement and modest retrofit interventions—in comparison to data collected in 2022 following MEES refurbishment works, to examine the influence of carbon reduction policies upon RHBs.

This study investigates RHBs, a typology often not investigated in carbon reduction policy research. It examines the connection between national energy performance tools such as EPCs and MEES and highlights the specific needs of historic dwellings. This research uses mixed-method techniques to conducts a rare 15-year longitudinal study (2007–ongoing) on 12 RHBs within a low carbon village setting to examine the implications of retrofitting from both technical and behavioural perspectives.

2. Review of Previous Studies

Whilst a drastic reduction in carbon emissions would slow climate change, an alteration in the climate is already certain [12], creating threats to the long-term survival of tangible built cultural heritage [13]. Thurley [14] asserted that ‘the arguments for keeping old buildings will shift from the old ground of historical and architectural value and will increasingly revolve around carbon reduction’. Creating a low-emission society frequently conflicts with the continued use of historic buildings [15], yet, as identified in the Heritage Responds report [16], decarbonising historic buildings is core to accomplishing net zero emissions by 2050 [17]. The Royal Institute of British Architects (RIBA) [18] estimate that twenty-five million existing homes will need to be energy-retrofitted over the next 30 years to meet 2050 carbon targets. Recent estimates by the UK Department for Energy Security and Net Zero [19] reaffirm this scale, projecting that at least 80% of homes that will exist in 2050 have already been built and emphasising the need to decarbonise the existing building stock. Moreover, the 2025 Net Zero Progress Report highlights how only 15% of historic homes are currently compliant with minimum energy efficiency standards, which represents a significant retrofit challenge for heritage assets. Therefore, it is imperative to improve energy efficiency within existing buildings, of which approximately 20% are historical (pre-1919), through the practice of retrofitting [18,20]. Berg [21] argues that the cost-effective and resilient retrofitting of RHBs should follow a ‘fabric first’ hierarchal procedure where improving the building’s thermal envelope, such as its insulation, windows, and airtightness, takes priority over introducing installation of energy efficient technology or renewable energy sources. This method aims to reduce energy demand at the source, making later upgrades more effective. Yet, ‘fabric first’ may not always be the most suitable approach, particularly in the context of a rapidly decarbonising electricity grid [22], where clean energy is more readily available. An alternative perspective within the heritage sector promotes a ‘think first’ approach, which prioritises understanding the building’s unique attributes, how occupants live in it, and how proposed changes might affect its historical value and long-term usability [20].

Comparatively, in other countries with similar heritage buildings, a more tailored approach is used for retrofitting heritage buildings. User-centric approaches have been provided more emphasis in the Scandinavian country of Norway, which focuses on occupant behaviour and non-intrusive intervention [23]. In Italy, an integrated approach which promotes blending numerical modelling with in situ monitoring for energy efficiency has been suggested for historical buildings [24]. Another review study, which focuses on historic buildings in Europe, suggests adopting technical retrofits such as draught proofing, glazing upgrades, and insulation upgrades [25]. The selection of strategies has been challenging globally due to the energy performance and comfort trade-off in historic buildings [26]. These international studies further suggest adopting a more flexible approach and focusing on developing a context-sensitive retrofit framework which includes both occupant behaviour and performance-based building evaluation as central focuses in heritage conservation.

Interestingly, the most significant durability problems experienced in existing buildings are the high demand for internal building comfort [27], with homes being the second largest consumers of energy in the UK after transport, largely due to the energy required to heat buildings [28]. Balancing thermal comfort with building preservation is one of the greatest challenges for retrofitting RHBs [18]. Empirical evidence reveals a significant discrepancy in residential buildings between the calculated energy demand and actual measured energy consumption of a household [29], which is described as the performance gap. As discussed, there is an established conflict between net zero carbon and MEES regulations within the EPC methodology of using the RdSAP to calculate energy efficiency of existing dwellings. Whilst an EPC permits comparisons to be made between different properties as a compliance tool [30], Gram-Hanseen [31] argues that EPCs should encourage energy reduction. However, current modelling software often underestimates the thermal performance of historic properties [32], providing an inaccurate picture of actual energy use; thus, suggested recommendations for retrofit are often not tailored to a building, nor are resident behaviours and values considered [33]. Research by Wise et al. [8] showed that the RdSAP overestimated the energy use within heritage buildings by an average of 66% and asserted that the accuracy of RdSAP tools must be significantly improved to inform correct retrofit decisions for RHBs by combining EPCs with metrics that reflect actual energy use, adding options for assessing the physical condition of the building, and applying behavioural tailoring. To achieve energy efficiency targets, tenant behaviours need to be considered throughout the energy retrofit process for success to be achieved [21], as homes do not consume energy, but people in homes with different types of practices and different technologies do consume energy [31]. Interestingly, energy behaviours in heritage buildings have been shown to differ in some contexts from those in modern buildings [34]. Whilst the environmental benefits of reducing carbon are prominent within the research literature, operational energy use is less so [8]. Fouseki and Cassar [35] support this further, stating that how people use a building is often more important than the type of energy efficiency technologies selected. Historic England [36] suggest that future research should undertake an occupant-centric approach, as, ultimately, Historic England buildings do not use energy—people do [37]. A Gap in energy use and occupant behaviour has also been observed across European heritage housing, which resulted in the recommendation of user-centric tools for guiding retrofits [38]. Furthermore, real-time monitoring technologies were also recommended, to align retrofit interventions with actual occupant behaviours [39].

In 2015, almost 79% of homes in England had an EPC rating of ‘D’ or better, compared to 39% in 2005 [40]. Whilst the accuracy of EPCs is debated, fundamentally, EPCs are a compliance tool from Part L of the Building Regulations, dealing with energy efficiency requirements [41]. Yet, householders’ understanding of EPCs is still considerably low, with Amecke [42] stating that the low relevance attached to EPCs can be attributed to policy circumstances rather than design and suggesting how increasing the importance of EPCs as a decision-making criterion for tenants would produce more valuable energy efficiency regulations. Using EPC ratings to drive lower emissions is unlikely to work in practice, as the ratings are linked to the type of energy and costs [43]. For example, the case studies evaluated for research are all off-grid, often using electricity to produce space heating, and are thus penalised on their EPC assessment despite having a lower rate of emissions produced by electricity. Passivhaus Trust [43] argues that, as carbon emissions related to expensive electricity continue to be reduced, the EPC rating system will become increasingly inaccurate, and suggests that space heating demand should be used as a primary metric to measure energy efficiency. The UK Green Building Council has been critical about the limitation of EPCs in evaluating true carbon impacts and advocates adoption of the Whole Life Carbon Roadmap, which integrates operational and embodied carbon, especially for hard-to-treat heritage buildings [44]. Moreover, simulation-based research on UK historic commercial buildings demonstrates that customised retrofit strategies, which are focused on building use and fabric performance, can perform better than EPC-based recommendations in terms of carbon reduction and practicality [45].

Berg et al. [21] state that ‘further investigations should study the interplay between policy instruments for energy saving, heritage and conservation principles, as well as the psychological drivers behind tenant energy behaviour’. The quantity of current research that projects concerning energy efficiency within historic buildings is a testament to the continuing importance of this subject area [46]. Yet, cultural heritage-specific research challenging climate adaptation efforts to minimise adverse impacts on built heritage is scarce within the climate change literature and policy documents [47]. Yarrow [48] presented how the application of general policies to historical buildings causes conflict between legislation promoting the preservation of cultural heritage and regulations that require the reduction of energy consumption within buildings, such as MEES regulations. Consequently, this study evaluated the recent National Trust refurbishment scheme in response to current MEES regulations, with its data collection focusing on occupant interactions with building fabric and services [49], as, although rebound effects are relatively well understood, research on aspects of occupant operational energy use is less reflected upon within carbon reduction research [8]. Additionally, there is a lack of data, both prior to and post-retrofit, which can be used to assess effectiveness of carbon reduction measures through case study research. As suggested by Berg [21], the retrofit hierarchal procedure to improve the thermal envelope before the installation of energy-efficient technology and conversion to renewable energy sources was investigated by using archival LCV project data. Ultimately, the inconsistency of policy regarding energy efficiency in historic buildings leaves a considerable amount of England’s existing building stock vulnerable to the impending climate crisis [50], creating a need to reduce the number of challenges derived from carbon reduction policies that are faced by RHBs.

Overall, this study presents a longitudinal study of the effects of carbon reduction policy on 12 real-world RHBs. At the same time, it evaluates the effectiveness of EPC-driven measures, highlighting performance gaps and conservation challenges by combining quantitative EPC data with qualitative occupant interviews.

3. Research Methodology

3.1. Selection of Low Carbon Village (LCV)

Low Carbon Villages (LCV) was a 3-year scheme between the National Trust and former energy partner Npower to research low-carbon living through the two Trust-owned villages of Coleshill in Oxfordshire and Cambo in Northumberland. The scheme involved working with communities to understand tenants’ carbon footprint and share practical solutions to reduce carbon and tenant energy bills. After an initial survey, energy efficiency interventions were implemented (e.g., loft insulation), with tenants being encouraged to reduce carbon through behaviour changes, such as switching off appliances when not in use. As well as houses from the location for the previous LCV scheme, 12 RHBs in Cambo (Figure 1) were selected for this research study (

Table 1. Building characteristics of the selected 12 RHBs.

RHB	Year of Construction	Designation *	Description	Building Usage	Heating System ‘x’ Identifies Heating System Before Works Whilst ‘+’ Highlights Heating System After Works
					Mixed Fuel Fire & Back Boiler	Oil Boiler	Stove	Storage Heaters	Electric Fire	Some Rooms with No Heating	Open Fire & Back Boiler	Electric Radiators	Biomass	No Heating System
1	1840	Not listed	Stone built semi-detached cottage	2 adults, retired	x	+	+
2	1850	Not listed, but attached to RHB4	End-terraced stone built cottage	2 adults, retired		x+
3	1875	Not listed	Stone built semi-detached cottage	2 adults, working			x+	x				+
4	1580	Grade II Listed	Stone built three-storey bastle house	2 adults, retired		x+
5	1740	Grade II Listed	Two-storey mid-terraced stone cottage	1 adult, retired				x	x	x		+
6	1750	Not listed	End-terraced two-storeyed stone cottage	1 adult, working	x	+	+
7	1740	Grade II Listed	Two-storey mid-terraced stone cottage, remodelled c.1880.	1 adult, retired		+	+				x			x
8	1750	Grade II** Listed	Mid-terraced stone cottage within courtyard of Wallington Hall.	1 adult, retired		x							+
9	1710	Grade II Listed	Semi-detached stone-built cottage.	2 adults, working and 2 children		+	+				x
10	1810	Grade II Listed	Semi-detached stone-built cottage.	1 adult, retired		+	+ (2 nos.)				x
11	1900	Not listed	Semi-detached stone-built cottage.	2 adults, retired		+	+				x
12	1750	Not listed	Mid-terraced cottage with rubble built north wall retained in the late C19th remodelling.	2 adults, 1 working (freelance) and 1 retired		+	+	x

Legend: “*” All RHBs are located within Cambo Conservation Area, Designation status affects retrofit options and EPC outcomes. Designations: Grade I—buildings of exceptional interest. Grade II—buildings of special architectural or historic interest. Grade II**—particularly important buildings of more than special interest. “x”—heating system before refurbishment works. “+”—heating system after refurbishment works. “x+”—heating system retained, but safety compliance checks completed only (no upgrade). Note: In some instances, a like-for-like option was adopted despite not being the best option for EPC grading due to cost and designation restraints.

), as recent MEES compliance refurbishment works had been completed on the same properties between 2020–2022, which allowed a longitudinal study to be completed, alongside assessment of any behavioural changes from tenants during the period (2007–ongoing) through semi-structured interviews, as shown in Figure 2.

Cambo was constructed between 1730 and 1740 to rehouse estate workers and comprises 32 solid stone-built terraced cottages with slate roofs. Importantly, Cambo is out of reach of mains gas, relying on oil, electricity, or solid fuel for heating, and, with very few exceptions, all cottages only have single-glazed sash windows. In this study, interviewees refer to the National Trust staff that were questioned, whilst interviewed tenants have been anonymised with case study references (e.g., RHB1, etc.) (see Table 1).

3.2. Interviews for Assessing of Carbon Reduction Policies

This research was longitudinal in approach, considering historic information gathered across a 15-year period (Figure 2), which was supported by in-depth semi-structured interviews with tenants of selected RHBs over a 6-month period (

Table 2. Tenant interview questionnaire.

Research Section	Challenge Area	Questions
Tenant Background	Tenants/Energy	1. Age category. 2. Size of household. 3. Length of tenancy—how long tenant has been resident at property address. 4. Decision to take on a National Trust tenancy, including exploration into positive/negative aspects of living on the Wallington Estate. 5. Do you see yourself as a custodian of the property? 6. A core objective of the National Trust is to make a positive contribution towards tackling climate change, including looking at ways to reduce carbon within the Trust’s residential let estate. How well, if at all, do you feel you understand what the National Trust is trying to do to tackle climate change? 7. Do you, if at all, contribute towards reducing carbon emissions within your home?
Property Background	Energy/Compliance	8. Size of property (m2)—information taken from EPC completed January 2022. 9. Number of rooms within property. 10. Heating source/s for the property—primary and secondary sources of heat. Does the property have an AGA cooker *? If so, gather tenant’s thoughts on contribution towards property heat energy consumption. 11. Have you made any adaptations to the property to improve energy efficiency? 12. Do you think heritage is a barrier to creating more energy efficiency homes? Researcher observations of property survey completed under this section during site visit, including notes about recent refurbishment works completed.
Energy Behaviours	Energy/Tenants/Compliance	13. EPC: do you know what an Energy Performance Certificate is? If yes, does tenant know current EPC rating for home and associated energy saving recommendations listed on the EPC? 14. Importance of utility costs when deciding to take on the tenancy. Would increasing future fuel costs and responsibilities of managing energy within a historic property cause you to look for a more energy efficient home? 15. Daily heat settings—what are they? Occupation—length of time at home? 16. Current energy-efficient measures and tenant behaviours concerning lighting and appliances (list provided). 17. Energy expenditure—monthly/annual fuel bill costs? 18. Do you have any non-energy related problems such as damp/condensation issues?
Refurbishment Programme 2020–2022	Tenants/Compliance	19. How did you find the refurbishment works process and have there been any positive outcomes so far (e.g., fuel bill reductions, etc.)? 20. Upon completion of refurbishment works, were you shown how to use newly installed appliances/controls/energy efficiency measures? 21. Would you be open to future works and disruption to your home if it meant improving the energy efficiency of the building further, therefore reducing running costs?
Low Carbon Village	Energy/Tenants/Compliance	22. The Low Carbon Village (LCV) Project took place in Cambo between 2007–2011, can you remember this project and what the aims were for this? 23. Reflecting on LCV, how do you feel your energy behaviours have changed, if at all in the last 10 years, towards climate change and carbon reduction (both at home and wider perspective)?

“*” “AGA” stands for Aktiebolaget Gas Accumulator—a traditional cast-iron heat-storage cooker, often used for heating and cooking.

). Furthermore, archival transcripts from staff and tenants were utilised together with current National Trust file notes from tenants. The interview questions listed in Table 2 were developed based on relevant thematic areas identified in the literature, such as energy performance, retrofit behaviour, tenant attitudes, and policy compliance. This study also considered the findings from earlier stages of the Low Carbon Village (LCV) project. Each question was designed to draw out detailed responses on specific challenge areas, such as the impact of refurbishment measures, tenant behaviours influencing energy use, and perceptions of heritage as a barrier to efficiency. This selection of criteria for the questionnaire ensured that the interviews supported the research aims of evaluating policy effectiveness, understanding tenant influence on carbon outcomes, and informing people-centred retrofit strategies.

The participants for the interview were selected using the purposive sampling method, with a focus on tenants residing in the 12 selected RHBs which are included in this case study. These selected RHBs were considered due to their involvement in both earlier LCV projects (2007–2010) and subsequent MEES upgrade work (2020–2022). All participants were long-term residents. The average tenancy length was 20 years, which allowed for longitudinal understandings of behavioural and perceptual changes over time. The tenants interviewed were from different age groups, which was done to include diverse perspectives on the retrofit experience and energy behaviour.

An interview pilot was completed before the 12 semi-structured in-depth interviews, ranging from 45 min to 2 h in length, were carried out at selected RHBs. The interviews involved all household members, apart from RHB9, where only one resident was available at the time of interview. This allowed tenants to be lead through a pre-determined interview schedule focused on research challenge areas, although the questions were not necessarily in a rigid order, which encouraged tenants to develop their personal reflections further. The use of semi-structured interviews, which were conducted in person at tenants’ homes, created a familiar and comfortable setting and led to candid and often detailed discussions. Many participants thoughtfully shared their experiences with retrofit works, energy use, and heritage concerns. Meaningful engagement with the research questions was further promoted by the occupants’ strong custodial attitudes towards their properties. Observations on the building fabric and interventions were recorded during property visits. Immediately after the interviews, the researcher’s perspective was captured [51], as the overpowering validity of observation is due to it being the most direct way of obtaining data [52]. Data from each respondent were subjected to an editing process before coding, an elementary form of content analysis, to examine the qualitative data collected through inductive coding by analysing the word and sentence structure within interview transcripts to extract themes relevant to core research objectives.

Table 3. Sampling: data collection and sample size for research parameters.

Research Challenge Area	Description	Data Collection Method	Sample Size
Carbon reduction policies (i.e., EPCs)	Investigate EPCs as policy tool when considering retrofit options.	Quantitative data collection through collation of EPC data for Northeast portfolio of the National Trust, using Parity Projects software 2024.	188
Tenants	Investigating tenant behaviour amongst National Trust residential tenants.	Semi-structured interviews with 12 selected RHBs tenant to ascertain tenant behaviour and thoughts on retrofit; use of previous LCV case study will add greater depth.	12
Compliance	Policy proposals to increase minimum EPC rating to ‘C’ and effect on RHBs.	Semi-structured interviews with National Trust colleagues on energy efficiency regulations, participants are from a single organisation therefore homogeneous sampling appropriate [51].	10

highlights the research challenge areas and the related data collection method, alongside the sample size obtained for this study.

4. Results and Analysis

4.1. Challenges to Implementing EPCs as a Policy Tool for Retrofit Purposes

To investigate EPCs as a retrofit tool derived from carbon reduction policies, we used Parity Projects, a software programme which assesses energy retrofit options, to analyse the EPC data to establish the current position of the National Trust’s let estate. Across the Trust’s northeastern residential portfolio, the average RdSAP (Reduced data Standard Assessment Procedure) score was 36.10—this score reflects the Standard Assessment Procedure (SAP) energy efficiency rating system used to generate EPC bands, which ranges from 1 (very poor efficiency) to 100+ (excellent). A score of 36.10 corresponds to an EPC ‘F’ rating, which indicates poor energy performance. Notably, only one RHB within the portfolio achieved an EPC rating of ‘C’. This illustrates a clear link between building age and lower EPC ratings, supporting the argument for policy clarification on long-term governmental aspiration to achieve minimum EPC ‘C’ ratings within existing housing stock. Often, mechanical and electrical interventions have a considerable influence on EPC ratings, whereas sensitive fabric interventions are limited in their impact upon the total rating. The EPC data revealed that 68% of the Trust’s RHBs in the northeast are constructed from solid sandstone walls which are rated ‘very poor’ within EPC documents. However, carbon reduction policies recommend internal or external solid wall insulation to increase the EPC rating to ‘C’, and yet ‘this retrofit option would never be implemented’ (Interviewee 1) due to the impact on hygric balance within historic wall structures. This highlights differences between energy efficiency regulations and the conservation of RHBs [36]. Whilst EPC data are often fixed to default assumptions, current research exposes a need for EPCs to be more appropriate for RHB retrofitting [53] as, alongside risk to building fabric if modelling is inaccurate, both environmental and financial targets may also not be achieved [54].

Interestingly, the LCV project invested £600,000 into basic fabric upgrades such as draughtproofing and fitting of sheep wool loft insulation on the Wallington estate, yet made no investment into heating upgrades. High demand for internal building comfort within existing buildings is the leading durability problem for RHBs due to the highest proportion of energy use being devoted to heating [27]. Consequently, the National Trust is facing complex decisions around energy production, particularly as secondary data analysis revealed that the Trust’s national RHBs are fuelled primarily by oil (52%). For this study, all RHBs are off-grid, which requires higher-cost fuels (Table 1), with only RHB8 being fuelled by low carbon biomass energy, benefiting from being located within the courtyard area of Wallington Hall, where a communal biomass system has been installed. Whilst the Trust is ‘committed to removing oil from properties and creating more sustainable heat energy sources’ (Interviewee 2), internal data revealed that, although this aim has been achieved successfully on larger mansion properties, such as at Wallington, the proposal is more complex for RHBs due to additional challenges from the heating levels demanded by tenants. Subsequently, a recent refurbishment scheme aimed to extend initial LCV project work by improving the thermal envelope of buildings before installation of more energy efficient technologies and considering future renewable energy.

In total, 88 RHBs required refurbishment works, with 38 being prioritised due to falling below Decent Homes Standards [55] and not achieving the minimum EPC ‘E’ rating; assessment of the selected 38 properties after refurbishment works showed only one renewable energy installation, with the remaining heating systems being updated with the same energy source (i.e., oil for oil), despite the internal National Trust policy to not install new oil boilers. However, it is important to recognise how EPCs fail to provide a complete energy audit of a building, focusing largely on the energy running costs of a building [32], where installation of lower-carbon heating systems can reduce EPC scores, while fuel is considered more expensive than other forms of fuel. For example, the use of LPG will decrease the EPC score comparative to an oil boiler due to higher fuel costs. Because the current EPC methodology emphasises fuel cost rather than carbon emissions, heating system replacements often prioritise cheaper fossil fuel options (such as oil) over more sustainable alternatives like biomass or heat pumps. As a result, systems are frequently renewed on a ‘like-for-like’ basis, simply to meet EPC thresholds, rather than being selected for their long-term carbon reduction potential. This creates a conflict between what EPCs reward and what organisations like the National Trust aim to achieve in terms of sustainability, as highlighted by Interviewee 2, who noted that the methodology often drives heating system replacements that contradict the Trust’s environmental goals. Since EPCs inform government-funded retrofit programmes [6], it is essential that actual energy use patterns, along with tenant behaviours and values [31], are incorporated into future carbon reduction policy frameworks to ensure that recommendations are appropriate and effective for RHBs.

4.2. Challenges of Tenant Energy Behaviours and Related Insights

To achieve energy efficiency targets, tenant behaviour must be considered [21], as one study revealed the assumption that tenants profit from energetic retrofits [56] is often not the case. In this study, 75% of tenants agreed that heritage was a barrier to creating a more energy efficient home, with heating costs being a concern for tenants despite many stating they ‘would just adapt to rising fuel costs’ (RHB2). Interestingly, increasing fuel costs would only cause 17% of RHB interviewees to consider looking for a more energy efficient home, with the majority stating that the location and other benefits were of more importance: ‘rising fuel costs would definitely not cause me to consider moving as I love the area’ (RHB10). Electric heating had been installed to improve the EPC rating at RHB5, yet one of the tenant’s statements reveals conflicts between EPC carbon reduction measures and the reality of utility costs: My electricity bill for the month of January was £277—that was with only three radiators working downstairs—so totally unsustainable. Importantly, interviews were held after refurbishment works had taken place, yet nine RHBs had further implemented minor changes to improve energy efficiency, with thick curtains across entrance doors being the most common adaptation, followed by draft excluders. One tenant had ‘carved wooden wedges to slot around certain window frames in the cottage to stop them rattling as the drafts are horrendous’ (RHB1) and RHB5 had installed ‘wooden shutters for each window unit to improve temperature control’, which highlights how, despite an improvement in EPC ratings, a ‘whole building approach’ had not been considered, as the tenants were still adjusting weaknesses within historic fabric to reduce heat loss.

Cross analysis of the interview transcripts revealed that National Trust tenants often have strong loyalties towards the Trust as a landlord, compared to tenants in the wider privately rented sector where lower levels of satisfaction and landlord loyalties result in shorter tenancy periods [57]. In this study, the average tenancy length is 20 years, with the longest being 83 years, which is significantly above the UK national average of 4.3 years [53]. Connected to tenancy length, 100% of participants identified as ‘a custodian and not merely just a tenant’ (RHB11), with RHB1 stating ‘I like to think I am looking after the property for future generations.’ Consequently, tenants are motivated to contribute to the wider estate community and have strong interests in the ‘future impacts of climate change’ (RHB3).

Heating and comfort behaviours in RHBs may differ from those in more modern buildings [34], with interviews highlighting tenant’s strong perception of being a custodian: ‘it is a privilege to live in a house like this’ (RHB4). Consequently, despite a strong desire to look after RHBs, there was a reluctance to embrace energy efficient appliances and technologies from tenants, particularly those 65 years old and above, with concerns of technology not being suitable for RHBs being a key theme. Yet, at five RHBs where smart meters were installed, the tenants were notably more aware of monthly energy costs and the impact of certain behaviours on energy usage. Utilising smart meters to understand how much energy is being used can assist in adapting properties to climate change [32].

Occupant behaviours, such as drying washing indoors, are known to have a substantial effect on heat demand [58]. Daily heat setting behaviours were explored within interviews, with 83% of the interviewees reporting related building concerns (

Table 4. Tenant energy behaviours and related building concerns (with tenant comments referenced).

RHB	Tenant Energy Behaviours	Related Building Concerns (i.e., Condensation, Repairs, etc.)
1	Wood burner stove only in the evening, oil heating on for 1 h every morning.	Considerable amount of condensation with some damp above stairs (blocked guttering identified).
2	Set temperature of 20 °C, heating programmed for 2 h use in the morning and in the evening.	Damp mentioned as having ‘always been an issue’.
3	Heating on as and when needed as tenants work shift pattern within healthcare.	Some damp, nothing major or cause for concern.
4	23 °C every day, set to come on twice a day.	‘Always lived in an old house so used to issues that this brings’; no signs of damp, cottage well ventilated.
5	Different temperatures for different rooms; 21 °C set throughout, less used areas (i.e., utility) set at 18 °C.	Visible damp and condensation issues.
6	Sporadic, no heating settings in place.	Significant damp within hall area (very cold).
7	Wood burners stove on throughout the day, heating on once every morning at 20 °C.	No issues to report.
8	Biomass heating system, heats the whole property at a consistent low temperature.	No issues to report.
9	20–22 °C average, has on a set programme to keep levels at consistent levels.	Ongoing contractor issues after refurbishment works; plaster snagging to be completed due to damp.
10	Oil heating system on every morning between 7–9 am at 20 °C, during day only sitting room radiator used.	Damp (efflorescence sited along with white furring on interior walls in specific locations).
11	Heat rooms only in use around 21 °C.	Serious condensation (windows).
12	Oil heating on in evenings only (21 °C).	Cold bathroom (location) causes condensation.

). The issues of damp and condensation were repeatedly mentioned by tenants, yet most expected these issues from living in an older property.

Only RHB7 and RHB8 reported no other property problems, with RHB8 strongly connecting improvements in moisture levels to previous installation of a biomass heating system reducing former damp issues: ‘biomass boiler is super! I am confident in the biomass system, these houses are cold due to the thick stone walls so it is better to have a consistent low temperature which the biomass can provide’. They noted that the only negative was that, when the ‘biomass does go off it is a bit of a nightmare as it is specialised equipment so it takes time to find a suitable contractor’. Importantly, RHB7 had no heating system before and attributed damp clearing from the understairs cupboard to a new heating system and a ‘change in behaviour in heating house with oil boiler and heat from stove’. Reflecting on the site visits, despite new heating systems being installed within properties to improve their EPC ratings, if tenants are not utilising heating technologies to the greatest effect due to fuel cost concerns or lack of knowledge, it makes carbon reduction strategies futile and damages the building fabric long term (e.g., damp penetration to walls).

Figure 3 illustrates energy behaviours of interviewed tenants, regarding which, overall, there are positive energy actions, particularly when it comes to energy efficient lighting, despite RHB4 not considering a change to more energy efficient lighting as they ‘do not like the light emitted from LED lightbulbs’. Interestingly, RHB5 stated they ‘wouldn’t turn the heating off when away as it takes so long to heat the cottage back up when it has been emptied for a while’, whilst most tenants would. Many tenants have decided to heat only the parts of the building that are actively used, alongside not heating bedrooms and consciously lowering heating temperatures. These findings support the identification from Wise [12] of spot heating as a strong theme when heating historic homes, particularly as the majority of tenants are retired (Table 1) and will thus potentially occupy the buildings for lengthier time periods.

These insights from tenants demonstrate the critical role of user perspectives in evaluating the actual effectiveness of carbon reduction measures in RHBs, highlighting the need for feedback-informed retrofit strategies.

4.3. Challenges of Implementing Compliance

The research showed how increasing the importance of energy efficiency as a decision-making criterion for tenants would produce more valuable carbon reduction policies [42]. Interestingly, only 58% of the tenants that were interviewed knew what an EPC was, with none knowing their current rating. RHB3 summarised most tenant perspectives: ‘[I] wouldn’t have a clue, couldn’t guess!’. Furthermore, this study revealed a practical conflict between net zero carbon targets and MEES compliance, with modelling showing that the Trust would have to invest around £98 million to bring all Trust properties to a minimum ‘C’ rating through appropriate energy efficiency measures and renewable energy technologies. Consequently, these tensions are causing the Trust to remain in a ‘sitting still state whilst clearer government guidance is awaited’ (Interviewee 2). However, it is essential to understand the UK government’s overall policy to provide detailed context for this situation. The UK’s national commitment to achieving net-zero emissions by 2050 is outlined in [59], which sets out sector-specific actions to reduce carbon emissions. Relevant initiatives that focus on the built environment include the “Boiler Upgrade Scheme”, which aims to accelerate decarbonisation. However, policies like the MEES and EPC-based assessments often overlook the nuanced constraints of RHBs. To assess further, EPCs were completed for each RHB following refurbishment works, with

Table 5. EPC analysis for selected RHBs.

RHB	Heating System (LCV Scheme 2007–2010)	Heating System (After MEES Refurbishment Works)	Cost of Refurbishment Works	EPC Rating (Before)	EPC Rating (After)	% EPC Rating Increase	EPC Potential Rating (As Listed on January 2022 EPC)
1	Mixed fuel fire and back boiler	Oil boiler and radiators, room heaters (secondary) and wood burner stove	£52,330	F (35)	E (50)	42.9	B (84)
2	Oil boiler (coming to end of life), wood burner stove	Oil boiler and radiators, wood burner stove	£59,473	F (36)	E (46)	27.8	C (79)
3	Storage heaters and stove	Electric radiators and stove	£28,007	E (42)	E (50)	19	B (82)
4	Oil boiler (coming to end of life)	Oil boiler and radiators, no secondary heating	£30,793	E (49)	E (49)	0	C (78)
5	Storage heating (2 rooms had no storage heaters)	Electric storage heaters, controls for high heat retention heaters	£141,165	F (22)	D (59)	168.2	B (83)
6	Stove and back boiler with radiators	Oil boiler and radiators, dual fuel (mineral and wood) stove	£104,003	E (50)	E (52)	4.0	B (82)
7	Open fire and back boiler—no heating throughout property	Oil boiler and radiators, dual fuel (mineral and wood) stove	£64,392	G (19)	D (60)	215.8	B (85)
8	Oil boiler supplies both heating and hot water	Biomass boiler (communal and installed separate to MEES refurbishment works)	£98,004	E (45)	C (69)	53.3	B (90)
9	Open fire and back boiler (for hot water)	Oil boiler and radiators, dual fuel (mineral and wood) stove	£219,056	F (30)	E (51)	70.0	C (79)
10	Open fire and back boiler (for hot water)	Oil boiler and radiators, no secondary heating—wood burner stoves x2	£219,056	F (22)	E (48)	118.2	C (79)
11	Open fire and back boiler with radiators (solid fuel)	Oil boiler and radiators, room heaters (secondary) and wood burner stove	£36,169	F (22)	E (53)	140.9	B (81)
12	Storage heating	Oil boiler and radiators, dual fuel (mineral and wood) stove	£104,003	E (50)	D (60)	20.0	B (85)

Note: EPC ratings in the UK are based on a Standard Assessment Procedure (SAP) score, which ranges from 1 to 100+. Ratings are grouped into bands: A (92–100), B (81–91), C (69–80), D (55–68), E (39–54), F (21–38), and G (1–20). Higher bands indicate greater energy efficiency. % EPC rating increase = ((EPC after − EPC before)/EPC before) × 100.

identifying the results of the EPC analysis, alongside the potential EPC rating of each RHB if suggested retrofit recommendations were undertaken.

Due to a lack of precise energy consumption data, it is difficult to provide accurate cost–benefit analysis. The anecdotal evidence gathered from the RHB tenants points towards a range of outcomes. Some noted modest energy bill reduction (especially where smart meters were installed or biomass systems were in place), while others were concerned over rising energy billing costs despite refurbishment work. Across the 12 RHBs, there was, on average, a 53.3% increase in EPC rating following refurbishment works, with a total spend of £1,156,451. After such significant staff and financial investment, it must be assessed if the resulting EPC ratings warrant the resources that were employed in achieving the often minor energy efficiency improvements. The results emphasise the uncertainty of MEES regulations regarding future proposals for RHBs. Clearly, there are cases where EPC ratings have increased significantly, which reflects evident retrofit measures, with RHB7 being a leading example in which the ratings have gone from G19 to D60 through the installation of a new heating system, improved insulation, and other fabric measures. However, whilst RHB5 improved from F22 to D59, examination of bills at the tenant interview revealed that the fuel bills were ‘totally unsustainable’ (RHB5), which prompted discussion into the suitability of selecting electric storage heating for RHBs.

Nine RHBs improved from ‘G’ or ‘F’ EPC ratings to ‘E’ or above as a result of refurbishment works, whilst the remaining three RHBs had started at ‘E’ and aimed to address compliance issues. RHB4 remained the same (E49) despite heating system control upgrades and RHB6 only increased by two points from E50 to E52 following installation of a new heating system. Potential EPC inconsistencies are further highlighted by comparing RHB6 with the cottage next door (RHB12), as both properties have the same floor area and layout, identical heating systems, and refurbishment works completed, yet, despite matching information on their EPCs, RHB12 achieved D60 in comparison to the E52 achieved for RHB6. RHB8 also started with an ‘E’ rating (E45), which increased to C69, making it the only property in the northeast portfolio to achieve ‘C’. This substantial change in result was derived from prior installation of a communal biomass system at Wallington, which permitted courtyard cottages to benefit and illustrated the type of EPC results that could be achieved through renewable energy heating solutions.

As discussed, installation of lower-carbon heating systems can actually reduce the EPC score where fuel is considered more expensive. Yet, irrespective of policy inaccuracies, the RdSAP is the industry recognised method for the measurement of energy performance and, whilst an update in 2025 is imminent, there are no plans for a completely new system. The Trust argues that ‘energy efficiency ratings are an inappropriate way to drive the most effective de-carbonisation solutions and can create perverse incentives where high carbon emitting heating options achieve higher scores because they are cheaper to install and run’ (Interviewee 2). This was evidenced within the selected RHBs, where 75% have new oil condensing boilers installed to achieve necessary MEES compliance. These are preferred over more expensive to install, yet low carbon, energy sources with potential to reduce tenants’ bills. Overall, the majority of RHBs obtained a minimum rating of ‘E’ (eight RHB), which was followed by ‘D’ (three RHB). Figure 4 reinforces that the current system is not fit for its purpose, with recommendations on completed EPCs revealing barriers to preservation through inappropriate suggestions for retrofitting, such as photovoltaics, which ‘would not be implemented on RHB due to location within a conservation area and therefore installation of solar panels would not be permitted’ (Interviewee 1).

Whilst clarification is sought over future UK carbon reduction policy regarding MEES regulations, landlords such as the National Trust are prevented from planning long-term carbon reduction strategies within their portfolios. Indeed, Interviewee 2 advised that the Trust had suggested a new form of EPC specific for RHBs to the UK government but ‘thinks we’ll have to work with what we have and therefore, will need to plan for compliance accordingly’. Figure 5 illustrates case study RHB7 before and after refurbishment works, providing insight into the level of compliance works carried out on selected RHBs between 2020 and 2022 in response to the MEES. During a site visit, the tenant presented the researcher with photographs showing the building in use from the early 1900s, revealing family members sitting in the same place in front of a former range cooker where the newly installed wood burner stove was now located. Previously, an open fire was in situ (left image) until 2021, with the tenant using coal as fuel, the highest fuel type for carbon emissions; significantly, an open fire will typically only be 15% efficient, with the remaining heat energy escaping up the chimney [60]. This progression of heating systems over time was a stark reminder of the transitory nature of heating systems within RHBs as technological innovations develop and the need for the National Trust to lead on creating long-term strategies to reduce the environmental impact upon their let estate, for example, investing in communal renewable heating solutions within their villages and influencing government policy frameworks in adapting compliance legislation for the historic built environment.

Importantly, the EPC rating for RHB7 increased from G19 to D60 due to the installation of a new oil heating system and additional fabric improvements, with the tenant stating how their ‘bills went up slightly but not by very much’. Furthermore, 50% of participants felt positively towards future energy efficiency works ‘if it meant reduced fuel bills’ (RHB5). For the remaining 50% who said no, the age of the tenant and not wanting any additional disruption after the latest refurbishment works were two recurring key factors deterring tenants from further energy upgrades. Additionally, tenants were asked to reflect on recent works to ascertain any positive energy efficiency outcomes, with mixed viewpoints being discovered throughout the interview process:

• RHB1: Happy with the system, but it is more expensive as bills are now more expensive due to supply issues to rural location.
• RHB2: Overall, very happy with works, noticed difference since systems have been improved.
• RHB3: Would have liked to have seen more energy efficient measures, such as secondary glazing, as drafts are still an issue.

Some tenants (RHB3, RHB4, RHB9, RHB10, and RHB11) felt they ‘weren’t listened to’ (RHB11) as they ‘know all of the ‘quirks’ with the house and where improvements could have been made’ (RHB3), stating that priority was not given to fixing real issues within the building. For example, RHB4 mentioned ‘windows are a disaster area’, thus emphasising the need to integrate occupiers in the decision-making process to deepen understanding of RHB needs [21] and to implement people-centred energy strategies rather than solely reducing energy demand through use of energy-efficient technologies. Interestingly, RHB4 suggested ‘long term tenants would invest financially in energy efficient measures’, which was supported by RHB5, where the tenant had already installed costly window shutters to control temperature levels as they were ‘even wearing a Christmas jumper in summer to try and reduce costs!’. Perhaps the Trust could consider partnership working with long-term tenants when formulating organisational carbon reduction strategies.

4.4. Recommendations Based on Lessons Learned

Interestingly, many participants remembered the LCV project without much prompting, particularly the tenant village hall meetings and proposals for installing a biomass unit at Wallington; RHB7 mentioned the LCV project without being prompted and felt it had a ‘lasting impact’ but would have ‘liked to have heard more from the Trust with follow up information’ on how suggestions could be taken further. Archival research enabled collection of tenants’ comments from the LCV project 15 years ago to enable comparison with feedback from the same tenants when interviewed 15 years later following recent refurbishment works. Selected comments are highlighted in

Table 6. Comparison of tenant comments from LCV project (2007) to comments after recent refurbishment works (2022).

RHB	Then Tenant Comments from LCV Project (Archival)	Now Following Refurbishment Scheme 2020–2022
2	‘We’re still using the meter (smart) after three years and we reckon it has cut our electricity use by a third. Everyone in the village seems to have heard how much we’ve saved from turning off the towel rail in the bedroom, we think it was costing £200 a year!’	‘We remember [LCV] project and the village hall meetings as part of getting tenants involved; I do think the Trust could sharpen up in putting in more long-term energy efficiency measures in sooner rather than later—it will save them money too’.
7	‘Eco-motivation is 90% saving money, 10% doing good. I’ve cut my electric bill—by half—from turning the TV off and not using things as much. The loft insulation fitted by the project is brilliant and the massive difference from that has made me interested in the draughtproofing too, but I don’t want a central heating boiler, I’ll manage with just the fire in my sitting room’.	‘You [researcher] persuaded me to finally get a central heating system two years ago and I’m now pleased this has been installed. I was concerned at first, but I have got used to the heating settings to create a nice temperature balance in the property. There is certainly more heat from the wood burner stove compared to the open fire, so that has been an improvement as well—I’ll admit it!’
11	‘It just seemed like the most sensible thing to do (referencing the trialling of energy-monitoring meters). It’s like another child. We check we’ve switched things off when we go to bed. We don’t leave things on standby. I stopped leaving the cooker on because even the light loses power. And we are always telling our son to turn stuff off’.	‘We continue to use a smart meter as it helps us monitor the fuel usage, which we like to be on top of. Now the new system is in place (oil boiler) we heat rooms only that are in use and the wood burner has been a definite improvement compared to the open fire that had been here—we have been surprised by the heat it throws off’.

.

Many tenants were positive about the scheme and, although public awareness and interest in climate change matters have increased in the UK, an individual’s behaviour and action against climate concerns may not always translate into more efficient energy use within their home. For example, RHB1 asserted that ‘climate change doesn’t exist’, yet most tenants recognised the need for carbon reduction, with RHB6 stating ‘climate change is an issue but not sure what can be done with old buildings’, whilst some tenants (RHB1, RHB5, RHB8, and RHB12) independently called the researcher after reflecting on the initial interviews to provide energy bill updates and further comments, revealing a desire to engage on the subject. Essentially, the best use for a building will often be the use for which it was originally designed [61], and the National Trust recognises the importance of tenants in looking after the Trust’s RHBs; RHB5 reflected how it was ‘nice to think the Trust are looking into sustainability long-term for tenants, as ultimately tenants are preserving properties for the National Trust’.

Whilst the Trust tenants were not motivated by utility costs alone, clear confusion around EPCs was evident, alongside a desire from tenants to become more energy efficient. The Construction Index [62] argues that ‘EPCs are outdated and should be replaced with Building Renovation Passports (BRPs) which set a clear pathway to decarbonise homes.’ BRPs would monitor MEES compliance obligations, identify retrofit measures, and attract tenants by presenting low carbon standards with low energy bills through proposed ‘green rental agreements’, thus encouraging building occupiers to have greater concern for personal energy use whilst visualising financial benefits. The Trust, as the UK’s largest private landowner, could exert influence at the policy level to ensure future digital platforms consider the historic built environment. Furthermore, the idea of tenants contributing financially towards energy efficiency improvements emerged from the interview data, for example, RHB4 stated how ‘long term tenants would invest in energy efficiency measures’, an idea which could be explored further by the Trust. The National Trust could immediately implement the need to collaborate with tenants within future refurbishment programmes as the research identified that there are many long-term tenants who understand their homes and ‘quirks’ deeply (RHB3). This could take the form of a tenant questionnaire and property walk through before any retrofit works to understand more about the property and how it is used. Whilst responsible retrofitting improves the energy performance of the RHB through technical interventions, a ‘whole building approach’ must be applied for success [33] and to ensure heritage assets are adapted for continued sustainability rather than the proposed ‘fabric first’ approach suggested by the UK Government.

4.5. Future Research Directions and Global Perspectives

The findings of this study highlight numerous challenges in the domain of RHBs that need further exploration. The current study emphasises the importance of tenant behaviour and the limitations of the existing EPC methodology for the RHBs, which necessitates further exploration of future research on scalable retrofit strategies that prioritise both heritage conservation and energy efficiency. Longitudinal studies collecting real-time energy consumption data post-retrofit across different types of heritage buildings (beyond residential) could provide a better understanding of the widespread impact on building performance and occupant behaviour over time. Moreover, detailed policy adaptation studies could potentially evaluate the practicality of introducing alternative certification tools, such as BRPs, that are focused explicitly on historic properties. Such a policy framework will also enhance policy clarity regarding historic buildings and improve the implementation efficiency across different UK regions in a true sense.

This can also be adopted through focused international benchmarking research, which can be conducted to understand how other countries, especially those with significant heritage buildings, manage the balance between conservation and carbon reduction. The historic buildings that are located in different climatic zones, especially in developing regions (such as South Asian regions), also warrant additional focus. These incorporate different sets of design parameters such as high thermal mass, natural ventilation, internal courtyards, and orientation-sensitive layouts [63,64]. These design attributes already support low-carbon living, which makes them a good starting point for comparison with historic buildings in the UK. Future research could explore how ancient sustainable practices (such as lime-based plasters, jali screens, and thick masonry walls) in these South Asian heritage buildings can motivate modern retrofit approaches in both developed and developing countries.

5. Conclusions

This study aimed to investigate the effectiveness of current carbon reduction policies on achieving net zero carbon emissions for residential heritage buildings (RHBs) by performing a long-term study (2007–ongoing) on a real-scale low carbon village located at Wallington Estate in Northumberland, England. It is observed that the current guidelines on energy performance certificates (EPCs) are ineffective in reducing carbon emissions, with evidence indicating that the current methodology needs to reflect a clearer evaluation of energy use, as it is not just a methodology but influences carbon reduction policies, which results in current EPC tools producing erroneous recommendations for RHBs. Tenant interviews sought to provide further depth to EPC quantitative data results, and, as human behaviour, thoughts, and feelings are partly determined by their context, it was important to interview tenants within their homes to collect energy behaviour observations, which revealed the importance of involving tenants to implement effective retrofit works due to their personal knowledge of the property, which is evident through tenant building alterations both before and after refurbishment works. Whilst EPC awareness was low amongst the interviewed tenants, archival documentation showed that tenants’ understanding of energy efficiency had improved over a 10-year period. Furthermore, tenant interviews revealed that occupant behaviour and heating controls are highly influenced by draughts that EPCs do not account for, and also showed that tenant behaviour has been a neglected area in building energy policies. Collecting actual energy usage data for RHBs using energy meters would permit tenant behaviours to be considered within future EPC methodology to generate clearer guidance for appropriate energy efficient retrofits within RHBs. Mitigation strategies to confront environmental threats from climate change are essential for the National Trust to protect historic buildings by employing the organisational value of ‘think now and for ever’. Ultimately, people and places are intertwined and, thus, we not only need to sustain and conserve the life of the building but also its custodians, changing the current preference for ‘fabric first’ to ‘people first’, especially when addressing the challenges of carbon reduction policies regarding RHBs.