Modern Buildings Are Already Failing in Extreme Heat - and the Architecture World Needs to Catch Up

People spend roughly 90 percent of their lives indoors. That figure makes buildings one of the most consequential interfaces between human health and climate - and it makes the design choices embedded in those buildings unusually important when temperatures begin to climb toward extremes.

A new book, Adaptive Thermal Comfort: At the Extremes, by Susan Roaf, Fergus Nicol, and Michael Humphreys, argues that the buildings the Western world has been constructing for decades are not equipped for the climate future they will need to navigate. The problems are not marginal. During extreme weather events, many modern buildings overheat. During power outages, some become uninhabitable. The energy required to keep them thermally safe is growing beyond what many middle-class households in developed economies can afford - and climate change will make that gap worse before it gets better.

How a narrow definition of comfort went global

The authors trace much of the problem to a 20th-century export: a particular model of thermal comfort that assumed sealed, air-conditioned buildings with non-opening windows were the universal solution. This model spread from the United States and Europe to the rest of the world, displacing locally evolved design traditions that had produced thermally livable buildings in climates ranging from tropical monsoons to desert heat.

The energy cost of this approach was manageable when electricity was cheap and climate was stable. Neither condition holds now. Glass curtain-wall buildings, with their large unshaded window areas, require enormous heating and cooling loads to maintain comfortable interior temperatures. As exterior temperatures become more extreme, those loads grow. Roaf, who is Emeritus Professor of Architectural Engineering at Heriot Watt University, describes continuing down this path as "a dead-end generation of unadaptable and thermally dangerous buildings that require so much energy to remain habitable, that only the very wealthiest will be able to afford to occupy them."

What climate-ready design actually looks like

The book draws on examples from traditional and contemporary architecture across multiple climatic zones. Mongolian yurts, Maori philosophy on human wellbeing, innovative naturally ventilated buildings in South East Asia, and community infrastructure strategies from Sweden all appear as sources of transferable principles.

The common thread is what the authors call "hybrid or mixed-mode" buildings: structures designed to maintain comfortable temperatures using passive means - natural ventilation, solar gain management, thermal mass - for as much of the year as possible, calling on mechanical systems only when passive approaches are insufficient. This is not a nostalgic return to pre-industrial construction. It requires careful climate analysis, materials knowledge, and architectural skill. What it does not require is burning continuously increasing amounts of energy to compensate for buildings that fight rather than work with their local environment.

One U.S. study cited in the book found that fear of crime during urban heat waves prevented residents from opening windows - a social factor that can override any architectural provision for natural ventilation. In Sweden, researchers found that older people meeting in a community hall experienced measurably better thermal comfort than they did alone in their homes at the same temperature. Comfort is physiologically real, and it is not exclusively a function of air temperature.

Who needs to act and how

The practical changes required span multiple levels. Individual architects and engineers need training in passive design principles that current curricula often underemphasize. Building codes need thermal performance standards that account for extreme conditions rather than average conditions. Urban planning needs to address the heat island effects of dense, hard-surfaced cities that amplify already dangerous heat events.

The book's framing is deliberately urgent. It does not present these changes as desirable refinements but as necessities - a response to a trajectory in which thermally dangerous buildings become an equity issue, separating those who can afford to cool their homes from those who cannot. The authors conclude with a call to relearn from the wisdom of traditional builders worldwide who have always designed for the extremes their climates actually produce.