When the heat becomes the message at LCAW 2026

London Climate Action Week took place during one of the hottest June periods on record. For many, this was not an abstract statistic. Offices became unbearable to work in and homes uncomfortable to live and sleep, exposing the fundamental limitations of buildings designed for a different climate. This is not just about short-term discomfort. It is a clear alarm bell signalling  that much of our built environment is simply no longer fit for purpose. At the same time, another reality was equally clear and evident this week. We already have solutions, yet we are not scaling them at the pace this moment demands.

Buildings that shape outcomes

Across the week, the contrast between buildings was striking. Some struggled in the heat, while others remained calm, comfortable and supportive of wellbeing. That difference reflects choices in design and materials that directly shape how people feel and function. An event at Paradise, the Bywater building where we held our Summit last autumn, offered a clear example, cool, calm and set among green space and trees providing natural shade. By contrast, many hotel venues were airless and hot, with poor acoustics creating environments I couldn’t wait to leave.

Built by Nature has recently funded a digest of peer‑reviewed research on the health and wellbeing benefits of timber and biobased buildings, soon to be published. It shows that these buildings are not only lower carbon, but also create healthier, more comfortable and productive spaces. This builds on earlier work with dRMM Studios and the Quality of Life Foundation, which found occupants feel more relaxed and comfortable in timber buildings. For too long, the conversation has been dominated by cost rather than value, but a broader understanding is now emerging that includes comfort, air quality and productivity.

Download study on Quality of Life

Timber as a clear solution

The climate impact potential of timber is enormous. New evidence launched during the Building for Forests and Cities event at Carpenters’ Hall we convened, alongside the Forest and Climate Leaders’ Partnership (FCLP) and Timber Development UK, on Thursday, highlights the scale of the opportunity and the urgency of action. The discussion was grounded by a new joint FAO and Bauhaus Earth assessment of the role of wood products in the bioeconomy. Increasing the use of engineered wood, such as CLT, by 20% in the construction of mid-rise multifamily homes alone could deliver potential emission reductions of around 236 million tonnes of CO2 per year, alongside significant carbon storage in buildings. Between now and 2050 that’s equivalent to saving the emissions of 7 years of global aviation. Even relatively modest levels of adoption can make a meaningful difference, underlining how much potential remains untapped. Professor Michael Ramage from the Centre for Materials Innovation at Cambridge University also reminded us of the staggering statistic that the timber required to build a 100m² apartment grows in European forests every 7 seconds, and we know that just 10% of the 92% of the timber that currently doesn’t go into construction could deliver 3.1 million additional homes every year.

Access the report

Aligning value and investment

Of course, most of the new construction that will take place over the next decades will happen outside of Europe and most notably in Africa, parts of Asia and South America. The development trajectory in these places is staggering. But while the potential environmental impacts are deeply concerning, the positive impact in terms of providing safe, resilient, affordable and dignified places for billions of people to live and work is huge.

At our event with FCLP, we heard from the governments of Brazil and Kenya, where aligning finance with the delivery of safe, resilient and affordable buildings is a clear priority. Stronger evidence on health and wellbeing, alongside the speed and efficiency of timber construction, can help shift decision making across the system, influencing investors, developers and policymakers. This is where collaboration matters. Progress depends on partnerships and on funders who enable both innovation and the evidence needed to scale it. We saw this throughout the week, with organisations such as Laudes Foundation, IKEA Foundation and Assemble bringing leadership to these discussions and helping to connect climate ambition with real-world delivery.

Our funding partners

What happens next

The need for better buildings is no longer abstract, it is something we feel every day, especially in extreme heat. Better buildings are not a future ambition but a present necessity, and the question is no longer what to do, but how quickly we can do it. What we choose to scale next will determine whether the cities we are building today are fit for the future and whether we deliver a built environment that meets the needs of people in harmony with nature.