Construction Declares. Architects Declare. Engineers Declare. The ‘low build agenda’. Growing numbers of design and construction professionals before the pandemic were already re-evaluating their objectives and professional paradigms in response to the Climate and Biodiversity Emergency.


Then, the ‘black swan’ event of a generation occurred as the pandemic prompted people worldwide to adopt new ways of working effectively overnight. As a consequence, the utility and suitability of millions of existing workspaces and living spaces – alongside the desirability of many work-life patterns – has been re-evaluated, prompting many to consider moving home or workplace. Suddenly, professionals in the built environment sector are faced with the spectre that some of our needs for buildings and built environments are changing.

In the fallout from the pandemic, as supply chain disruptions and labour shortages seem everywhere to push up construction prices, and property prices soar as a consequence of rising demand (and limited supply), our instinct might be to simply open the tap: produce more materials, drive costs down, build more and thus drive property prices down.

However, a new reality has emerged in which building more is simply no longer tenable. We need to do more with less – in fact, a great deal more with much, much less.

Let us consider our decarbonisation goal as one example. Analysis by the International Energy Agency (IEA) defines a Net Zero Scenario that would allow the built environment sector to decarbonise in line with global targets, which calls for all new buildings and 20% of existing buildings to be zero-carbon-ready as soon as 2030 and 50% of existing buildings to be ready by 2050. To be clear, this is a tremendous challenge beyond imagination today (and the challenges posed by our biodiversity and broader sustainability crises are similarly daunting). Against this, final energy use in buildings globally has been steadily increasing, rising by an average annual rate of 1% between 2010 and 2019, as the average annual expansion of floor area proceeded at roughly twice this rate.

But wait, the naïve optimist insists, a plethora of design and construction innovations, sustainability assessment and accreditation systems, and advances in technical knowledge has led to significant improvements in the sustainability of new assets. This has allowed buildings and assets today to provide equivalent utility to yesterday’s designs with lower adverse sustainability impacts and increased benefits. Surely, we simply need high-performance buildings?

Unfortunately, the reality remains that nearly the entire global design and construction industry employs a linear, ‘take-make-waste’ process to build buildings, towns and cities, and this is reinforced by countless trillions of dollars in manufacturing and infrastructure, vested interests and systems of professional training and education that remain largely blind to sustainability concerns. Consider the embodied impacts of the materials and construction techniques that relate to resource extraction, production and manufacture, transportation, maintenance – and consider the difficulty of reuse or recycling – and it becomes clear why ‘business as usual’ in construction is no longer acceptable. The production of cement alone accounts for between 7% and 8% of annual anthropogenic carbon emissions, yet cement is so essential to modern construction that design and construction industries scarcely know how to build without it. Meanwhile, steelmaking accounts for a roughly equivalent share of global carbon emissions, and many other materials and building components have similarly outsized carbon and environmental footprints. In net terms, conventional new construction is very rarely or almost never actually, truly sustainable.

Clearly, we cannot forego all new construction – and this is particularly true in contexts where utility, amenity or condition of built environments are inadequate. In these places, despite the global exigency of throttling down resource consumption, some new low-impact construction will remain essential. Elsewhere, though, if we as societies are to achieve net carbon neutrality while becoming nature-positive, we simply cannot build our way to this outcome. To borrow a phrase from a famous physicist, we cannot simultaneously prevent and prepare for climate change by turning to new construction – its impacts are simply unsustainable.

As climate change, biodiversity and wider sustainability concerns have entered the public consciousness writ large, regulatory, policy and market drivers have expanded proportionally and professionals across the built environment sector faced mounting pressure to provide ‘sustainable solutions’. For many in more progressive localities or forward-looking organisations, decarbonisation and nature-positive goals have moved from marginal concerns to fundamental ones. For everyone, the direction of travel is clear: individuals and organisations across the sector will increasingly be called to meet increasingly challenging sustainability targets.

The good news is that to a great extent, the answers already exist. We can (although we do not always) renovate and retrofit buildings without large quantities of cement, steel and other ‘high-impact’ materials; and without the high embodied carbon and environmental impacts associated with conventional new construction. Meeting needs through reusing and repurposing buildings can be achieved sustainably and economically today – at a time when we can least afford the additional carbon and environmental impact associated with new construction.

So, let us rejoice! If we must learn to do more with less, we already have the assets, the technology and the knowledge that this requires.

A seismic change is coming to the sector as meeting needs with new construction becomes increasingly uneconomic and untenable. Decision-making and perceptions of value are already changing rapidly as sustainability grows in importance, and logically, this trend can only continue. The risk of stranded assets looms large as the direct and indirect impacts of climate change make resilience and adaptability more desirable and inefficient unsustainable assets less marketable.

Professionals in this rapidly changing landscape must consider new forms of value and new forms of demand. The Climate and Biodiversity Emergency calls for all of us to rethink and reimagine our professional remit, and so it bears asking, ‘how should individuals and organisations prepare for this ‘low-build future’?

Dr Tim Forman, Cambridge Institute for Sustainability Leadership