The key decisions when developing homes for more extreme weather are made at the early stages of a design. Begin with an in-depth site search and a pencil and paper to make notes and sketches with. Simulations disassociate the building from its site and waste time servicing the tools rather than thinking deeply about what you want from a building, and how to achieve it. Inevitably we want occupants to remain safe in their homes even during extreme events. Picture the early design in two stages: Start with the site’s environmental Humours, then go on to creating a healthy home with a steady Thermal Pulse.
Stage 1: Respect The Humours: Ancient Greek Physicians and Philosophers used four Humours to describe the workings of the human body: Earth, Air, Fire and Water. No building can be safe on a site without considering these. THE major design choice for resilience relates to location. Never build on land that might flood or is drought-prone. Research exposure to local fire risks. People underestimate the power of winds in destroying buildings and fueling fire risks. Many learnt too late of this danger during the Palisades Fire of January 2025, triggered by the Santa Ana Winds. Dreams of building retirement homes with wonderful views are often shattered by landslides during storms so consider carefully the terrain around a site. Respect the Humours.
Stage 2: Design a Thermally Well-Behaved Home. During extreme weather local grid often fail so design a thermally resilient building. Four indicators of a resilient building are:
- A low amplitude thermal pulse in the building, in which over days / seasons the internal temperature swings are modest rather than psychotic. This is achieved by careful orientation of the building form, the size and location of its windows and inclusion of thermal mass internally that can store solar gain in winter or night time coolth in summer to temperature shift and shave. The same amount of glazed opening in the wrong place in a light weight highly insulated building, say with all the windows in one wall facing west towards the low hot sun in heatwaves can turn a structure into a killer building during extremes. Similar amounts of glazing differently orientated in home with high mass internal walls in similar insulation levels can provide life-saving coolth or warmth for occupants.
- An internal Thermal Reservoir. Including an energy store in a water tank, battery or heavy mass walls can slowdown the rate of heat or coolth loss or gain. When a grid fails it is vital that the internal climate only slowly loses or gains heat to keep occupants thermally safe for as long as possible. The old, thick-walled, mud-brick homes of the South West of the USA acted as Capacitive Insulation that slowed down the ingress or exit of heat and if the wall was thick enough, a fly-wheel effect developed so the internal and the external temperature gradients in the wall acted independently to keep indoors cool on hot days and warm on cold days.
- Effective Natural Ventilation Pathways. These in a home enable the building to be run for as much of the year as possible on local renewable energy like sun, wind and warmth / coolth from the earth (basements are useful for this). Air moves heat / cold under pressure from local winds through buildings. Buoyancy also enables heat to be dumped up and out of buildings during heatwaves when safe to do so, and to dump cold down into building on cooler nights as cold air sinks just as hot air rises. Obviously the longer you can run a home on local energy, including solar hot water and photovoltaic systems, the lower its energy bills. Importantly it also means that once the grid fails occupants can survive much longer indoors by managing airflow indoors and charging / discharging heat / coolth stores with varying air flow directions and speeds. Fears for safety may require security grills on windows (possibly doubling as strong insect screens?) but no home anywhere should be built without opening windows from now on.
- Internal Thermal Landscapes with Climate Refuges. A building is not a box powered by a machine. A home can contain a range of different thermal micro-climates: warmer rooms facing South in the USA; colder rooms facing North; rooms on the East and West will have their own Thermal Pulses over the days and seasons. During extreme weather around a home the externally facing rooms will be more or less exposed depending on orientation and the weather risk. In an ice storm the North rooms may get the full force of a blast, in a heatwave the South and West rooms will be more exposed to the weather hazard. Design in extreme weather climate refuges for both hot, cold and wind extremes. On wind / sun / cold / heat exposed facades a bank of ‘buffer spaces’ including habitable rooms or storage / service spaces may provide protection to inner spaces. Thermal reservoirs might best be included in mass walls around internal climate refuges. Vertically, thermal floors or roof spaces can buffer too aided by fans or extra insulation.
What is proposed above is nothing new. It is not Rocket Science, but it increasingly reflects the thinking of those already shoring up their homes and property portfolios in more climatically exposed US regions. In Louisiana complying with the voluntary Fortified Construction Standard adds significant value to properties (https://www.ldi.la.gov/fortifyhomes). In Florida the My Safe Home programme give grants of up to $10,000 to enhance the resilience of structures (https://mysafeflhome.com/). The Oklahoma government offers rebates for Homes with Safe Rooms (https://oklahoma.gov/oem/programs-and-services/soonersafe-safe-room-rebate-program.html ) where property search engines like Willow maps those properties with storm shelters that offer the extra benefit on hurricane resilience (https://www.zillow.com/oklahoma-city-ok/storm-shelter_att/ ).
These programmes focus on enhanced structural integrity during high winds, but with climate change heat and cold are killing more than wind. It is now the thermal resilience of building that is the key life-saving attribute for homes in many US states. Start designing with a pencil and paper, as the design develops move on to simulations with the HVAC function off, because when the grid fails so will the mechanical systems. Simulate the building in future climates to ensure it behaves well in more extreme climates and most importantly of all remember that at the extremes it is the quality of the building itself that will save you, not the machines.
Sue Roaf (B.A. Hons, A.A. Dipl., PhD, FRIAS, HonDEng) is Emeritus Professor of Architectural Engineering at Heriot Watt University, Edinburgh and Honorary Professor at Deakin University, Melbourne and at the University of Queensland. An award winning architect, teacher, author and activist. She has written and edited 24 books on solar and sustainable design, thermal comfort and climate change adaptation and currently leads the Comfort At The Extremes movement: https://comfortattheextremes.com/
The themes explored in this piece are developed in detail in her 2026 book on Adaptive Thermal Comfort at the Extremes:
For a fuller Biog:
Sue Roaf – B.A. Hons, A.A. Dipl., PhD, FRIAS, HonDEng is Emeritus Professor of Architectural Engineering at Heriot Watt University, Honorary Professor at Deakin University, Melbourne and at the University of Queensland and has an Honorary Doctorate in Engineering at Southampton Solent University.  An award winning author, architect, teacher and solar energy pioneer. She grew up in Malaysia and Australia and after a first degree she spent ten years in Iran and Iraq, on archaeological excavations, nomadic migrations, and researching desert technologies. Her 24 books include those on The Ice-houses of Britain, Ecohouse Design, Energy Efficient Buildings, Adapting Buildings and Cities for Climate Change, Benchmarks for Sustainable Buildings, Adaptive and Resilient thermal comfort, Natural Energy Buildings and Transforming Markets in the Built Environment. An ex-Oxford City Councillor, ex-Governor of Ruskin College Oxford, ex-member of the UK’s Architects Registration Board she is an ex-Director of AES Solar Energy Ltd., Director of Ecohouse Initiative Ltd., Director at 100percentrenewableuk and an advisor to the Resilient Design institute in New York. She has chaired and (co-) organised many conferences including www.plea2017.net, www.cate2024.org, www.comfortattheextremes.com and www.icarb.org, ,. She led Scottish Government programme on Adaptation in the Built Environment from 2010 to 2016, and now leads the Comfort at the Extremes movement, working in Antarctica from 2019 to 2024 and now with researchers in marginalised communities in Australia on climate-safe design.
