In addition to general studies on sustainable innovation in the construction industry, numerous studies have addressed particular innovative materials, such as those presented in Chapter 4. Unfortunately much of this research has focussed on demonstrating the technical performance of alternative materials, with authors repeatedly noting a dearth of corresponding qualitative studies assessing the cultural, behavioural, or perceptual barriers to adoption within design teams (Watson et al., 2012; Wong et al., 2013). The bulk of qualitative research conducted to date has focussed either upon general approaches to material selection amongst design teams or barriers to the adoption of particular materials (e.g. timber) and narrow groups of materials that share a common characteristic (e.g. high recycled content). Little work has been done to synthesise the common barriers and address the underlying factors restricting uptake of alternative materials. The following section attempts to synthesise results from existing studies, before considering barriers to a more general group of low carbon materials.
The most comprehensive overview of factors preventing the selection of ‘non-conventional’ materials is provided by Zhang and Canning (2011). The authors assert that the principal barriers are the lack of associated short-medium
term commercial benefits; effective marketing and dissemination of information on new materials to practising engineers; and supportive material performance data and full-scale demonstration projects. The authors argue that this can be combated through the addition of design guidance alongside effective marketing and stakeholder engagement. On the basis of this, the authors propose a model for introducing new materials. This model begins with identification of the target market and requirements for technical compliance. This assessment is followed by development of supportive performance data and demonstration projects. From this initial design guidance can be assembled and disseminated. Uptake should be driven by effective marketing, and performance and design guidance must be persistently reviewed and revised. The authors demonstrate this through a case study of an advanced composite decking system. Whilst the authors place an emphasis on the provision of material information to designers as a key means of promoting sustainable material choices, even in cases where sufficient information and demonstration projects are available, material choices are typically governed by other priorities. An international study of design teams conducted in 2012 by Arup for the WBCSD demonstrated that, although a large number of factors influence material choice, cost was the overarching priority and material sustainability criteria were often less influential than the personal knowledge and past experiences of the project team (Arup & WBCSD, 2012).
The literature review described in Section 4.2, encountered an array of barriers, presented in Table 11. Whilst the review considered a diverse range of materials, it is clear that they share many common barriers. In practice, the suitability and sustainability of a particular material is highly dependent on site and project-specific factors. The lowest embodied carbon solution will vary across structure types and from project to project. The end goal of policy makers and advocates of low carbon construction must be to promote the most appropriate option for each particular project. Therefore simultaneous promotion of a wide variety of material options is essential. This requires skills development and legislation that is sensitive to, and supportive of, this multitude of options. Therefore, whilst it is crucial for focussed studies to assess the barriers to adoption of particular materials, it is also essential to identify the leverage points and interventions that can overcome common barriers and support multiple solutions.
This broader approach was adopted by Watson et al. (2012) when conducting an online questionnaire and series of subsequent interviews assessing the barriers to entry for non-conventional building materials. Watson surveyed 62 UK construction professionals on their opinions and views of alternative materials, how often these materials are used and what influences their use. Results demonstrated that awareness of many alternative materials such as rammed earth, CLT and straw bale infill was high, but use remained low. Over half of respondents had
not considered using non-conventional materials and less than ten had practical experience. Respondents believed that architects had the greatest influence on material choice (though the respondent demographics featured a strong bias towards structural engineers). The principal barriers identified were high costs, lack of technical knowledge and lack of client knowledge.
Jones et al. (2015) further explored the underlying barriers to the adoption of novel materials in the UK construction industry through an empirical study of the adoption of CLT. (It should be noted that this study was conducted at the same time as the survey and interviews presented later in this chapter). The study featured a survey of 49 construction practitioners (of which 70% were architects), followed by 8 semi-structured interviews. 27 of the survey respondents had experience using
Institutional and
Access to finance for SMEs Project financingTable 11: Common barriers to the uptake of low carbon building materials
CLT, whilst a further 7 had considered use but were unable to get the material adopted. Concerns over risks to project costs and unfamiliarity with the product were identified as the two key barriers. Projects that achieved successful CLT adoption were typically low value (<£5m), for non-commercial clients, and featured proposals for CLT use by designers at the early project stages. The single greatest driver of CLT adoption was ‘client concerns for the environment’, which were cited in 29.4% of adoption cases. However, in many instances, CLT was selected to meet unique project requirements, such as site constraints, with the associated sustainability benefits a secondary concern. This led the authors to conclude that
“unique project contexts formed by client values and experience, site constraints, or planning and regulatory requirements, create niche-like environments with conditions which might not be satisfied by dominant technologies, requiring an alternative approach to construction… understanding and exploiting these niche conditions is key to successful deployment of unconventional approaches.” Precedents from the field of innovation studies describe how such technologies can exploit niches before emerging through ‘windows of opportunity’ to change overarching socio-technical regimes and break existing industry path dependencies (e.g. Geels, 2004).
Ariyaratne and Moncaster (2014) considered the approach of designers to embodied carbon assessment and mitigation through a survey of 37 industry practitioners and 6 expert interviews. Whilst the survey principally focussed upon embodied carbon assessment tools, it also highlighted some of the common barriers to low carbon design and material selection. In practice many of the most important design decisions were made prior to any environmental performance analysis. The authors observed that this “lack of early integration of sustainability assessments into the design process leads to extensive modifications being required at later stages to meet the performance criteria.” This prevents inclusion of certain alternatives and increases the cost of others. These problems were compounded by a dependence upon “experience and…tried and tested methods”. Designers also experienced difficulties presenting the value of carbon assessment to clients, particularly in the current economic climate. The authors identified “that under most circumstances, it was unclear how the environmental impact assessment of designs are being carried out or who was taking the responsibility for carbon reduction. There was a certain sense of passing the responsibility to another discipline, particularly towards sustainability consultants.” The authors argued that overcoming this problem will require clear allocation of responsibility and “a new-breed of designers with the right set of skills and approach.” The authors argued that “from a designer’s point of view, developing low embodied carbon designs could be considered as a state of mind. It is the cultural awareness that needs to be bred into the designers in a similar manner to how the awareness of health and safety was raised within the industry.”
The three general studies highlighted here, and the numerous studies of
specific materials, exhibit a number of recurrent themes. Namely: the lack of early engagement of certain project professions; a failure to consider embodied carbon in early project stages; a shortage in knowledge and skills amongst designers; negative perceptions of alternative materials; ineffective allocation of responsibility amongst project participants; and the fundamental lack of drivers for adoption of innovative low carbon solutions. The survey and interviews presented in the remainder of this chapter explore these barriers in greater depth and consider potential drivers for adoption of low carbon materials.
5.3 Research methodology, objectives and boundaries
The overarching objective of this chapter is to understand the cultural, behavioural, and perceptual barriers to adoption of alternative low carbon building materials amongst industry practitioners involved in design, specification and construction. The preceding literature review highlighted the range of economic, technical, practical and cultural barriers preventing construction professionals from selecting materials commonly identified as being lower in embodied carbon.
The following survey and interviews explore these barriers in greater depth than prior studies and consider the role for regulation, professional institutions and advocacy groups in overcoming these barriers. The following paragraphs set out the approach and study boundaries and explain the respective survey and interview methodologies.
5.3.1 Boundaries
Despite the recent growth in understanding, embodied carbon remains a niche topic within the construction industry. Therefore the surveys and interviews did not seek to recruit participants that would constitute a representative sample of the UK construction industry at large; but rather targeted individuals with extensive experience of using low carbon materials. The UK represents a global leader in this field, and UK construction practice is widely emulated throughout the world. The vast volume of overseas project work conducted by UK practitioners based within multinational firms contributes to an international spread of British construction practice. This is supported by the common international use of British and European standards and environmental assessment methods, such as BREEAM.
Thus understanding the views and experiences of early adopters in the UK is crucial, as these early adopters will ultimately shape both domestic and global practice.
Understanding their motivations and experiences is informative in developing appropriate regulatory strategies and guidance for the broader industry.
Construction industry supply chains are typically lengthy and complex, involving a variety of professions. Many of these actors have fundamentally different motivations and priorities. In this study an attempt was made to limit participants
to professionals involved in the design, specification and construction process.
Professionals involved in these disciplines have previously been the subject of various studies assessing general barriers to sustainable and green building but their views relating to embodied carbon and materials had not previously been comprehensively addressed. The survey and interviews were not targeted at developers, end-users or material manufacturers. Further specific studies that focus on the perspectives of these groups would be valuable additions to the research field.
5.3.2 Overarching approach
The initial assessment of barriers to the adoption of low carbon materials is derived from the literature review already detailed. This initial compilation of barriers became the subject of further research which adopted a mixed method approach combining a survey and series of semi-structured interviews. A sequential explanatory approach was selected, whereby a survey would gather initial quantitative and qualitative data on the barriers to adoption, followed by interviews exploring the identified barriers in greater depth. This approach is commonly used across a range of disciplines (see Tashakkori & Teddlie (2003)) and was selected to provide the desired combination of breadth and depth.
5.3.3 Survey methodology
An open online questionnaire was hosted using Qualtrics and made available from 03/04/14 to 23/05/14. An open online questionnaire was deemed the most appropriate format as it provided the means for practitioners to easily share the survey and maximise the number and range of responses. Links to the survey were distributed through a number of major industry mailing lists, established contacts, LinkedIn groups and to a targeted set of individuals with extensive experience of using low carbon materials. Flyers with a survey link were also distributed at events during the UKGBC Embodied Carbon Week (07/04/14-11/04/14). Participants were encouraged to pass on the link to colleagues and contacts. Owing to the self-selection process, the sample of respondents is predominantly constituted of industry practitioners with an active interest in the topic and experience using the range of materials discussed. The sample is not reflective of the broader industry but provides an insight into the motivations and experiences of those early adopters who already have experience using a range of less common materials.
The limitations of the survey sample are discussed further in Section 5.7.
The survey was designed using a mix of open and closed questions. In all instances where respondents were asked to choose from a prescribed list the opportunity to add other options and provide comments was made available. The survey featured 17 core questions (see Table 12) with additional piped questions depending upon the participant’s response. A full list of questions and all possible
responses can be found in Appendix C. The core questions focussed on gathering demographic data; establishing the perceived influence and responsibility of respective professions on material selection and embodied carbon reduction;
gathering respondents’ experiences with a range of 24 example low carbon materials;
and exploring perceived barriers and drivers to the adoption of low carbon materials.
The 24 example materials were selected to provide a range of both novel and traditional products. This included materials developed from natural sources;
materials incorporating waste streams or recycled content and products optimised through novel production techniques. The materials were selected from a long list developed through the literature review, with preference given to materials included in prior qualitative studies to allow for comparison of results. The final 24 materials included were: Brettstapel; Cross Laminated Timber (CLT); Structural Insulated Panels (SIPs); straw bale (either load bearing, infill or modular); rammed earth; unfired brick;
cob; adobe; hemp (including hemp-lime composites); limecrete; cardboard (tubes or panels); Ethylene Tetrafluoroethylene (ETFE); inorganic Fibre Reinforced Polymers (FRP); geopolymer concrete; concrete containing agricultural wastes (e.g. rice husks, vegetable fibres or nut shells); concrete containing consumer wastes (e.g. plastics,
Table 12: Survey questions
1. What is your job title?
2. What is the typical project role of your employer?
3. In which country do you normally work?
4. For how many years have you worked in construction?
5. Approximately how many staff does your company directly employ?
6. How much influence do you have over the selection of materials and construction products on a typical project?
7. Who do you believe has the greatest influence over material and construction product selection on a typical project?
8. Please rank who you believe should ultimately be responsible for minimising the embodied carbon emissions on a project.
9. What is your knowledge of the following materials and construction products?
10. How often have you used each of these materials?
11. How would you rate your experience of using each of these materials?
12. Thinking about the projects on which you used these materials. Why did you choose to use each material?
13. Would you use these materials again? / Why would you not consider using these materials again?
14. You stated that you are aware of but have not used the following materials on a project. Why have you chosen not to use these materials?
15. Thinking more generally about alternative materials in construction, how important do you believe the following factors are in preventing their use?
16. How important do you believe the following developments could be in encouraging greater use of alternative materials and construction products?
17. Is there anything else you would like to add about any of the topics discussed?
glass or tyres); concrete containing construction and demolition wastes; concrete containing industrial wastes (e.g. steel slag, sewage sludge ash, silica fume); precast hollowcore floor slabs; optimised roll-out reinforcement meshes (e.g. BAMTEC or ROLLMAT); recycled aggregates; recycled plastic lumber; reclaimed steel; and reclaimed timber. This does not constitute a comprehensive list of all low carbon materials available in the construction marketplace. Such a list would be too lengthy for inclusion in a short survey and would likely reduce the survey completion rate.
Respondents were initially asked to describe their knowledge and experience of each of the 24 materials by selecting from 3 options: ‘used on project(s)’; ‘aware of but not used’; or ‘little or no knowledge of’. Questions 10-14 were then filtered to gather respondents’ experiences with each of the materials that they had used, and reasons for not selecting materials they had not used. Following the questions about specific materials, respondents were asked to consider more general barriers and drivers to alternative materials. The survey was structured in this form to allow comparison between the specific experiences of practitioners that had used each material with the perceptions and barriers reported by practitioners that were not using that material. This was a deliberate attempt to help distinguish potential perceptual barriers.
Following an initial draft, survey questions were reviewed by an independent academic with extensive experience conducting industrial surveys. A revised version was then tested and further refined based on responses from a pilot group of architects and engineers. Following minor amendments, a final round of sit in testing was done to ensure full understanding of the questions, prior to distribution.
5.3.4 Interviews methodology
All survey participants were asked if they were willing to take part in a follow up interview exploring the topic in greater depth. 24 out of 47 respondents indicated a willingness to do so and provided contact details. Survey participants demonstrating particular experience were selected for a short series of in depth
Table 13: Interviewees
Position Type of Organisation
Sustainability Manager Multinational contractor
Senior Engineer Large multidisciplinary consultancy Architectural Technologist Specialist architectural practice Director of Sustainability Professional institution
Assistant Head of Sustainability Large client
Sustainability and LCA Expert Research technology organisation
Founder Sustainable Business Partnership and Chair of Embodied Carbon Task Force
interviews. Additional interviewees representing specific professions or industry bodies were also sought to provide an appropriate breadth of expertise.
The interviews were semi-structured and typically of an hour in length. All interviews were conducted face to face and recorded for transcription. A common set of questions and prompts were prepared, tested and refined through a test interview. These common questions were designed to build upon responses from the survey. Additional questions specific to the experiences of each interviewee were also prepared to maximise the quality of responses. All interviewees were offered anonymity, which some declined. A full list of interviewees can be seen in Table 13. Recordings were transcribed, coded and subjected to thematic analysis.
This was conducted in the common software package NVivo 10. Open coding was used to identify salient issues from the interview transcriptions. Axial coding was then used to extract the key distinctive and recurrent themes. The discussion of results is framed by these themes.
The following sections present results from the survey and interviews in turn. The subsequent discussion draws results together and provides a number of recommendations.