Upscaling bio-based construction: challenges and opportunities

Figures & data

Figure 1. Methodological framework which formed the basis of the semi-structured interview questioning.

Table 1. Professional position and experience of interviewees. All interviewees were based in the United Kingdom at the time of interview. The table also lists the bio-based materials at the forefront of the interviewees’ experiences.

Interviewee	Position of interviewee	Circular, Bio-based project perspective and experience
Interviewee 1	Chief Executive Officer of a mid-cap public limited company which seeks sustainable solutions in all aspects of construction, manufacturing, and distribution and has won numerous awards for environmentally friendly practice. The interviewee has been with the company for over twenty years	Private sector client; oversaw the conception, planning, and realization of an industrial-scale circular bio-based building which could be extended from a corporate perspective. Materials used in the build included glulam, sedum-roof and hemp-lime blocks.
Interviewee 2	Founder and director of a company specializing in bio-based research, manufacture, and consultancy and dedicated to a bio-mimetic circular future for the built environment. The company has been active for a decade.	Consultant, academic researcher, and entrepreneur; developing and marketing innovative bio-based construction materials and designing circular construction systems. Specializing in mycelium and use of biological waste materials.
Interviewee 3	European Commission external evaluator, bio-based organizations ambassador, and diversity consultant. Multiple decades of experience include positions within UK government departments such as Energy and Climate Change (DECC) and Environment, Food and Rural Affairs (DEFRA).	Civil servant, consultant, and decision maker; Evaluating proposals relating to multiple aspects of bio-based projects and material construction and development.
Interviewee 4	Executive Director and professorial fellow within a University faculty, with a background in biology. Active in environmental policies for over thirty years.	Academic; project-led the realization of an industrial-scale bio-based project on the campus of a university and currently continues leading research and development of circular, bio-based construction projects on campuses. Materials used include glulam, timber, thatch and reed, and recycled paper.
Interviewee 5	Senior manager within a British national museum group facility, overseeing the conservation of historic artefacts. The interviewee held the position for seventeen years.	Public sector client; championed and oversaw the use of bio-based materials, principally hempcrete panels, in a completed industrial-scale building.
Interviewee 6	Senior manager of a division within a large private retail company, a position held for over five years.	Private sector client looking to build upon the success of previous sustainable building projects with a programme of circular, bio-based construction. Materials used by the company include hemp-lime and earth.

Table 2. Summary of key finance-based challenges and opportunities for circular bio-based construction. Where interviewee(s) responses informed a bullet point, the interviewee number is indicated.

Finance: Challenges

Finance: Opportunities

High initial costs of emerging materials (1-6) Higher design costs of materials (5) Company structure: potential opposition amongst multiple shareholders or board members within a client organization on grounds of initial costs (1,6) Temptation to buy globally rather than locally on grounds of cost (4) Potential of circular bio-based elements being value-engineered out of projects on grounds of cost (1,4) Reluctance to shoulder the financial burden of risk (4) Establishing a contract and working arrangement all stakeholders on a project are prepared to accept (1,4) High costs involved in upscaling a product to be available in construction-scale quantities (2,3) Costs of gaining certification and accreditation for emerging products (2,3,4) Costs of developing a new standard if an existing standard cannot be used (2) Clients being able to continue to provide maximum service levels to customers (6) Established companies not welcoming financial competition from emerging materials (2,3)

Long-term savings to be made on building operational and energy costs due to environment-regulating properties of materials (1,5) Publicity and dissemination can lead to networking opportunities for clients and the formation of new commercial relationships Standards such as the wellness agenda and equivalent promoting occupant health and well-being (2,3) Increased occupant wellness – customers prolonging being in the building and potentially higher productivity and lower absenteeism amongst staff (1,4) Development of low-interest or interest-free loans from authorities for circular, bio-based construction use and development Regeneration of local and regional economies – labour, trades, skills, crafts, farmers (3,4) Opportunities for smaller companies with emerging materials to partner with larger companies for development and accreditation, ultimately sharing in financial rewards gained (2)

Table 3. Summary of key finance-based challenges and opportunities for circular bio-based construction. Where interviewee(s) responses informed a bullet point, the interviewee number is indicated.

Knowledge: Challenges

Knowledge: Opportunities

Many bio-based materials are emerging products and knowledge may not be readily available or widely known (2,3,4) Construction industry professionals and clients are reluctant to work with emerging materials with which there are low levels of knowledge (2,3,4,5) Circular construction can conflict with existing certifications, for example PassivHaus which requires airtightness (4) LCA for bio-based materials is challenging with regards to how to assess the end of life scenario and the gradual emission of carbon over one or multiple design lives (2,3) LCA for bio-based materials can result in a poor score if unsustainable land practices such as the clearing of natural land or mono-crop farming are practiced to profit from crops intended for construction (2,3) Crops for construction purposes being grown geographically far away from construction sites can further impact on LCA with transport considerations (2,3,4) Case studies are very important and there are currently not enough (2,4) It is a source of disagreement as to which stakeholders should be knowledgeable; construction industry professionals, clients, or a mix of both resulting in an exchange of ideas A project requires a ‘champion’, senior within a client company, to counter internal opposition and realize a circular bio-based project (1,6)

Existing databases and information sources to be linked/merged and maintained/updated with new developments (3) Disseminate that materials have performed successfully in terms of regulating internal environments – maintaining temperatures and reducing fluctuations in RH (3,5) Clients can demonstrate and publicize commitment to sustainable/environmental values and wellness among staff/customers/building occupants (1,4,6) Staff and customers from client companies can translate sustainable behaviours and practice into their personal lives (1,6) Knowledge of modular and circular design can promote designing for disassembly and/or adaptability, extending the service life of a building as use requirements evolve Smaller scale case studies, as well as industrial scale, can demonstrate and educate that circular bio-based construction is possible on domestic as well as industrial scales (2,3) Construction industry professionals to be encouraged to become certified on sustainable design (for example PassivHaus and refresher courses) reflecting new developments can be attended to update knowledge (2,4) Project champions and sustainability champion employees within a client can promote a sustainable culture within an organization which can inform construction decisions (6)

Table 4. Summary of key finance-based challenges and opportunities for circular bio-based construction. Where interviewee(s) responses informed a bullet point, the interviewee number is indicated.

Policy: Challenges

Policy: Opportunities

Policy in other industries suggests legislation at national and regional levels is required to promote circular bio-based construction (1-6) The construction industry has not been at the top of government agendas, with energy (nuclear, solar, wind) and alternative sectors such as automobile taking priority (3) Challenging national and international circumstances and crises such as economic downturn, pandemic, and geopolitical events can impact policy and the capability to prioritize circularity and sustainability in decision-making (1,3,6) Construction is a global industry and policy is required to drive a change towards localizing construction (3,4) Punitive legislation has been implemented in other industries (automobile, chemical) – would punitive measures be appropriate for the construction industry? (2,3,5) Positive legislation to promote circular bio-based construction requires care and regulation to prevent profiting from subsidies by unqualified and unscrupulous parties (3)

Greenbelt planning applications can be an opportunity for circular bio-based construction, with bio-based materials sympathetic to a natural environment and landscape (1) Subsidies to increase crop growth and associated trades, skills, and crafts would promote supply and create regional regeneration, boosting regional economies, local employment and business, with crops grown, and by-product materials made, locally to construction projects (1,3,4) Positive legislation to price in new technologies and emerging products would help diversify construction, with the aim of traditional (concrete, steel) and emerging bio-based materials sharing the market, removing reliance on one or a few solutions (1,2) A dynamic approach to legislation would help to trial policies for a time period to evaluate worth and impact (2) Further research into the use of ‘contaminated’ land unsuitable for food crops