Last year we at @Revalu had the pleasure to sit down with some of the building industry’s most notable leaders, thinkers, and innovators to share some thoughts on the current and future directions of industry. We’ve taken a selection of insights from these conversations as a starting point to reflect on what we've learnt about some of the opportunities and challenges our industry faces, and how we might navigate these to move forward at the pace required. 

“Education needs to be core when scaling new materials as I believe many people want to do the right thing but they don’t know how” (Liz Gilligan, Material Evolution). 

A substantial part of the architectural design process revolves around the precedent: we study and learn about how buildings have been built, what materials they’ve been built with and how to draw their respective details. From education to practice, this persists. A considerable amount of what we continue to turn to for inspiration however (take Jorn Utzon's Sydney Opera House and Le Corbusier's Villa Savoye, for example) was built at a time when current climate related challenges weren’t so prominent.

Take concrete, one of the oldest construction materials to date: some sources credit Nabataea traders from around 6500 BC for their initial development of a concrete-like substance (Davidovits, J. 2023), whilst others credit the Romans. Its origins notwithstanding, concrete is still one of the most used materials in construction, a reality we may find difficult to escape: 60% of the buildings needed by 2050 have yet to be built (C40, 2023), a large proportion of which are likely to rely upon such a material. Due to its prolonged use we have accumulated a considerable amount of well-documented knowledge and experience; it is cheap, globally accessible, extremely versatile and easy to specify and build with. Recent developments in material science and innovation have brought to market a number of exciting alternatives and innovations that could contribute to reducing the environmental impact of our buildings whilst meeting our continued need for such a material: Fly ash; Recycled Aggregates; Geopolymer concrete and cement; Paebbl; Ecolocked and Cemfree are just a handful of such examples.

Although traditions are hard to change, the question remains: should we lean away from concrete and focus instead on innovative and bio-based alternatives? The answer might seem obvious, but transitioning away from concrete and other widely used carbon intensive materials presents a number of challenges. As Gilligan points out, education and the necessity of scaling knowledge transfer alongside material use are key challenges to overcome. This provides an interesting opportunity for our educational institutions: could they not provide greater opportunities for the architects of tomorrow to collaborate more closely with innovative and bio-based material manufacturers? 

Not only could newly graduated architects achieve increased agency but so too might they emerge as experts in their own right, fostering a bidirectional knowledge exchange together with established architects. In turn, this could contribute towards bridging the knowledge-gap that exists today, which is not only limited to the recently graduated but also observed in established industry professionals. 

“Unfortunately, there are not a lot of contractors and builders who are used to building with circular, earth-based materials” (Anton Mærtens, BC Materials)

Last year we witnessed the amendment of the Danish Building Regulation 18 (referred to as BR23) which amongst other changes set a gradually decreasing threshold limit on the carbon footprint of new buildings greater than 1,000m2 in size (due to be updated in 2025). Following the amendment of BR18, a considerable amount of industry-wide upskilling and increase in awareness and construction knowledge concerning bio-based materials occurred. Such proficiency is not only critical to enable a reduction in our industry’s impact but essential for industrial compliance. As we start to build with new materials and understand their tolerances, dependencies, risks and opportunities, it is imperative that this new knowledge be shared no matter the competitive advantage it might bring. 

Manufacturers and suppliers of innovative and bio-based materials are aware of the challenges faced and provide considerable documentation, advice, and information concerning how to specify and build with such materials. Companies like Havnens Hænder, for example, invest considerable effort in providing such knowledge to industry. It should not however be the sole responsibility of these actors to share such knowledge: a concerted effort across the industry is required, from architects to contractors, insurers and everyone in between to accelerate the transition towards bio-based materials. All actors can contribute, but is it enough to equip an industry with the requisite knowledge in order to continue building, just with better materials?

“We need to understand which material serves best in which part of a construction to use as little as possible and as much as necessary” (Fabian Hörmann)

The increased documentation and communication of material specification—particularly concerning Life Cycle Assessments (LCAs)— is likely to both encourage the use of bio-based materials and simultaneously clarify the quantities necessary to meet stringent regulations (especially concerning insulation). No matter how low-carbon a building or a material, it is important to remember that its production still requires considerable labour, transportation and manufacturing processes, all of which have an impact on our planet.

Data transparency and accountability play a critical role in ensuring the effectiveness and reliability of this information. With an evergrowing repository of bio-based materials available on the market (albeit in some instances at higher initial costs until economies of scale are achieved), as their procurement becomes commonplace the effectiveness and accuracy with which we specify them must not be ignored. Despite the considerable amount of regulations in force  and forthcoming, it is still possible to build certain typologies with the materials of the past. Considering the urgency we face, should this be the case?  

“We need rules that will demand for at least a % of the building to use biogenic materials…” (Armor Gutierrez Rivas)

Whilst gradually decreasing carbon threshold limits enable our industry to adapt over time and increase its capabilities concerning new methodologies (such as LCAs), a minimum requirement of bio-based materials could have a significant impact in accelerating a reduction in our building industry's footprint. It has the potential to develop economies of scale for bio-based materials resulting in a reduction in costs, increased availability, and enhanced market readiness. Such a policy would additionally stand to benefit the establishment of a new knowledge-stock concerning bio-based materials, addressing some of the obstacles faced concerning their application and procurement. 

A minimum requirement of bio-based material within buildings would surely stand to benefit many, yet our industry’s sensitivity to cost fluctuations and market availability remains steadfast. As nations seek to reduce the impact of their respective building industries in line with Nationally Determined Contributions (NDC’s), it is a variety and combination of policies and subsidies that may prove effective in accelerating the industry’s uptake of bio-based materials. Requiring LCAs and facilitating the creation of product-specific Environmental product Declarations (EPDs) are one of many measures that can be adopted: European-based programs such as the Circular Bio-based Europe Joint Undertaking (a partnership between the EU and Bio-based industries consortium (BIC)) alongside Horizon Europe and national start-up incubators and funds play a considerable role in bringing innovations to market. 

Whilst the role policies play in affecting industrial change is central, so too is identifying and addressing established cultures, as these are typically the hardest to change. The culture (and privilege) of dwelling size is one that directly affects material consumption and consequently a nation’s footprint. In Denmark for example, the average household size is one of the lowest in Europe at 2 people per household (Eurostat, 2021), who share an average home size of 112.6 m2 with an average of 1.9 rooms per person (Bolius, 2023). To extend our coverage to consider a frequent outlier in home sizes, Australia boasts an average household size of 2.5 people (Reserve Bank of Australia, 2023), with the average size of a new home in Australia currently sitting at 184.65m2 (ABS, 2023). 

“Unless we find some ways of limiting that [Our physical footprint], such as living smaller and smarter, in other words to densify, we will not be in line with our targets.” (Jacob Blak, Cobe)

The Danish Housing Construction from 4 to 1 Planet initiative aims to facilitate and guide Danish industry towards the reduction of a dwelling’s carbon footprint from “an average 10 kg CO2eq./m2/ year to 2.5. kg CO2eq./m2/year before 2030” (Build, 2023). Of note, the initiative explores an alternative unit of measure to the current kgCO2eq./m2/year used in Denmark, proposing instead m2 floor space / occupant. Despite studying a limited sample size of 25 cases, the report identifies single-family housing to have both the highest resource consumption per m2 and per person. In light of this, we need to not only be extremely mindful of when and if we build new, but also the energy and spatial efficiency of new and existing residential housing.

Affecting a cultural shift is notoriously difficult to achieve, and is no different in the case of the building industry with home-ownership (and size) still considered a symbol of wealth. As governments grapple with the difficulty of providing additional dwellings in the race to address increasing populations and housing affordability, the dilemma of doing so with a minimal environmental footprint remains. In Romania, the Programul Noua Casa (New House Program) offers a guarantee of up to 50% the price of a home under 50m2 (up to 60% for new-builds), unlocking access to more than €6 Billion in loans since its introduction (Unaffordable and inadequate housing in Europe, 2023). Although the act of building a new single-family home should be strongly considered (especially bearing in mind the environmental footprint per m2), a shift towards smaller, more accessible housing is a necessity that cannot be ignored. 

Not all policies work in all contexts, and it is important for our policy makers to be aware of successes irrespective of their origin, just as it is for architects to be aware of which construction methods and material solutions have worked in contexts outside of their own. For this to happen however we need effective and transparent knowledge sharing, not to mention the appropriate mediums through which to do so. There also needs to be the intent and authority to share, which for some might require the relinquishing of IP or explicit permission from clients.

No matter how complicated, considering the state of the planet and its future condition we must, as Katrine Juul from Henning Larsen put so eloquently:

“Share knowledge. Whether it’s about how to use biogenic materials for a building project or how to build at larger scales with them… anything that can help others progress” (Katrine Juul, Henning larsen)

There is a growing need for our industry to emerge from its individual silos and collaborate as a more fluid collective of individuals benefiting from the immense stock of knowledge contained within. Making available the knowledge held within an organisation to those outside is a first step many can take (with minimal effort). Fortunately, a number of organisations globally have started to do exactly this: Fitzpatrick & Partners’ Embodied Carbon Tool, Eckersley O’Callaghan’s embodied carbon tool EOC2 and Vandkunsten’s OpenSource initiative are just a few examples of organisations that have made available some of their in-house knowledge. 

Alongside carbon-related tools, some architectural organisations are collaborating with both private and public stakeholders alike to develop new materials. Grimshaw, for example, has teamed up with the University of East London’s Sustainability Research Institute together with Tate & Lyle to develop sugarcrete, expected to make its market debut later this year. Lendager Group has likewise founded and spun-off A:gain (now majority owned by North East Family Office), a company whose business model focuses almost entirely on the development and upscaling of bio-based and innovative materials for the construction industry. Such deviations from the typical business model of the architect are just some notable examples of the cross disciplinary and inter-organisational approach some within our industry are taking to solve industrial scale problems. 

No matter our position, stance or ability to influence change as individuals we must all be conscious of our collective responsibility to act. Affecting meaningful change is rarely straight-forward: if it was we likely wouldn't be facing such an uncertain future. As an organisation committed to affecting industrial-scale change in the building industry we have achieved an incredible amount in the past year, but we still have a long way to go. As we embark on the year ahead and digest our learnings from 2023 we could think of no better way to close these reflections than with a quote from our interview with Paloma Gormley from Material Cultures:

“Seek to understand the real impact of the work that we do and advocate for practices that offer hope.” (Paloma Gormley, Material Cultures)