**1. Introduction**

#### *1.1. Construction and a Sustainable Supply Network*

Activity in the construction sector globally is expected to rise by 70% to 15 Trillion USD by 2025 [1], linked to global economic development associated with rising middle classes, increasing populations and a move to greater urbanisation. The sector generates around 50% of the waste by volume in developed countries, while buildings account for 19% of the world's energy-related CO2 emissions. Construction is identified by the United Nations Environment Programme as a key area to address to mitigate climate change, a position echoed by the most recent IPCC Assessment Report [2,3].

In the UK, the construction industry has been dominated over the last 30 years by the development of a subcontracting culture, driven by "market forces" and leading to work allocated primarily through competitive tendering. The resulting construction networks have been characterised as "hollowed out conglomerates" [4]: "temporary multiple organisations", created to respond to bespoke client requirements requiring involvement of many value-adding organisations [5]. As a result, the sector forms a complex supply network including investors, developers, public bodies, architects/designers, contractors, manufacturers, raw materials suppliers and demolition experts (see Figure 1). Main contractors act as project managers for clients, drawing together all the skills, services and materials required to create a physical asset. It is their role to procure goods and services, albeit frequently to a pre-ordained plan, and they are increasingly reliant on subcontractors

and suppliers; these purchases represent typically 75% of their turnover [6,7]. The resulting fragmentation has created a supply network in which relationships are highly competitive and frequently adversarial [8,9], leading to narrow profit margins for main contractors, a major cause of the recent demise of the company studied in this work (Carillion) [10]. Relationships between network actors remain primarily dyadic, i.e., between the client and main contractor or main contractor and Tier 1 supplier [11], and the structure provides a limited basis for the development of trust between network members or collaboration in a supply network that is rarely managed beyond the first tier [12–14].

**Figure 1.** Simplified structure of a construction supply network [15]. Key: Increasing depth of shading in boxes demonstrates increased level of influence by Main Contractor. Increasing size of box indicates estimated increasing responsibility for impacts.

Despite these constraints, the UK Government has recognised that meeting sustainability targets in the construction sector depends on sustainable supply chain networks [16]. This creates a structural tension within the sector as the effective managemen<sup>t</sup> of supply chains has become largely synonymous with collaborative forms of working [17]. Indeed, the sustainable supply chain managemen<sup>t</sup> (SSCM) literature highlights collaboration and governance as powerful tools for facilitating sustainability initiatives [18]. For major construction contracts, changing business models have been shown to facilitate more collaborative working, including a move from "build" to "design and build" and "design, build, operate", the last an increasing feature of public–private partnerships. There has also been an associated increase in partnership working to win major contracts, e.g., involvement of multiple major contractors and manufacturers in the London Crossrail project or the formation of joint ventures (JV) such as CarillionAmey for MOD contracts. However, there is evidence that collaboration does not always result in beneficial outcomes [19,20]. It can also be difficult to achieve, as demonstrated in an industry-wide survey of 87 German firms by Brinkhoff and Thonemann which identified a 50% failure rate in collaborative supply chain relationships, the greatest issue being the difficulty of defining shared objectives [21].

There is a widespread view that sustainable consumption and production can only fully be achieved if the objectives of performance (economic, environmental and social) and principles of behaviour (quality) are shared, leading to common objectives, targets and requirements throughout the

whole value network (e.g., [9,20,22,23]). This is not ye<sup>t</sup> observed in the construction sector. For example, the industry annually procures over 380 million tonnes of resources [24] but inefficiencies within the network lead to 10–30% of waste materials being "unused product", including 800 ktons of shaped and sawn timber [25]. From a social perspective, the UK construction sector has been identified as a source of UK-based modern slave labour [26], with a significant proportion of the global 45.8 m people estimated to be subjected to modern slavery working within construction supply networks [27,28]. However, given the narrow profit margins noted above, the UK construction sector is typified by a focus on cost rather than value, with many companies seeking to transfer risk to others within the supply network. This acts as a strong inhibitor to undertaking initiatives directed at the environmental and social components of sustainability and heightens barriers to collaboration across the supply network.

Thus, although construction is an important sector for the promotion of sustainability in practice, it is characterised by serious structural problems. This paper reports on a heuristic study on the suitability of the Sustainable Development Goals (SDGs) in offering an effective collaborative framework to improve the social and environmental performance of the sector. In-depth interviews, surveys, and published sources have been examined, focusing on two different approaches implemented within one UK main contractor, Carillion plc (Wolverhampton, UK).

#### *1.2. Sustainable Development Goals*

The Sustainable Development Goals were adopted in 2015 [29] by the member states of the United Nations, in agreemen<sup>t</sup> with representatives of civil society and business, with the intention of guiding the global development agenda to 2030. They can be seen as an attempt to take the familiar representation of sustainability as "The art of living well within ecological limits" [30], complying with three sets of constraints—techno-economic efficiency, environmental compatibility and social equity [22]—and represent it in more tangible terms. In total, 17 different goals have been articulated, presumably divided in this way to aid understanding, acceptance and implementation. However, the SDGs are strongly interrelated, for example in ecological concerns such as the "nexus" of climate change, water availability and food supply, and in ethical concerns such as equity and justice. There are therefore questions, explored further in this paper, over the value of dividing the integrative concept of sustainability into so many apparently distinct goals.

Progress towards the SDGs to date has been slow [31]. The UN states that "Implementation and success ... will be led by countries, with all stakeholders ... expected to contribute to the ... agenda" [32]. In the UK, in 2017, a review by the Environmental Audit Committee of the House of Commons [33] concluded that " ... the Government seems more concerned with promoting the goals abroad, and has undertaken no substantive work to promote the Goals domestically or encourage businesses, the public sector and civil society to engage with the Goals and work towards meeting them". For commercial companies, the SDGs potentially represent a framework for articulating their social responsibilities and incorporating them in strategic planning. However, given the imprecise language and abstract level of many of the 169 targets, it is difficult to see how business could easily incorporate these into their practices. In addition, it is far from clear that the significance of the SDGs is sufficiently widely understood. For example, a recent survey [34] reported that more than 20% of European companies see "sustainability" as a source of competitive advantage but did not record to what extent they have truly grasped the concept as an imperative beyond commercial interest. The response most often reported is that companies are "developing products or services that will provide solutions in line with the Global Goals" [31], rather than attempting to embed the SDGs in planning and operations.

#### *1.3. Responsible Consumption and Production*

Notwithstanding the question over the value of subdividing sustainability goals into so many distinct categories, we focus in this paper on SDG12: Responsible Consumption and Production. This particular goal is selected because it is seen as one of the most central, relating closely to many of the other goals (many of which are subsidiary to this particular SDG), and ye<sup>t</sup> is considered to be one of the five SDGs on which there has been least progress [30]. Furthermore, it requires attention to the whole supply network delivering products or services. Therefore, this goal provides a useful basis for exploring approaches to embed the SDGs into planning and practice.

Responsibility in supply chain managemen<sup>t</sup> implies operating within ecological limits, as represented by the Planetary Boundaries defining the "safe operating space for humanity" [35,36], although there are serious difficulties in developing an operational approach to planning based on the Planetary Boundaries [37]. However, recognising that "sustainability" includes social equity, supply networks need to be more than just sequences of activities operating within ecological constraints; a supply network can be viewed as a set of relationships that convey benefits in both directions [23,38]. This view is exemplified by the fair trade movement, but has a more general significance in informing concepts of sustainable consumption [22]. Social responsibility in supply networks is a strong concern in the approaches examined here.

This paper reports an empirical investigation into approaches to network managemen<sup>t</sup> in a UK-based multinational construction company, to explore how the SDGs—specifically No. 12: Responsible Consumption and Production (SDG12)—could be incorporated into planning and operations in a commercial company by contrasting "bottom-up" and "top-down" approaches to goal-setting. The results proved to be sufficiently informative to generate some conclusions with wider implications.

#### **2. Selection and Exploration of Approaches to Embedding the SDGs**
