Keeping cool on campus

The summer of 1900 was a warm one as well.

The literary source for this observation is LP Hartley’s The Go Between, which sets something of an atmosphere as young Leo repeatedly checks a thermometer on the wall of an outhouse at Brandam Hall in breaks between oiling Ted’s cricket bat, buying a green suit in Norwich, and (spoilers) stumbling across an illicit liaison.

The temperatures he records in his diary reach 92°F (what we would describe as just over 33.3°C) one languid August day in direct sunlight on a stone wall. If we look at temperature records for the year that’s not far off the 1900 annual maximum for ambient temperature – it got to 35.1°C at a weather station in Cambridge in late July.

In 2026 official observations got to 37.7°C at Lingwood in Norfolk – not far from Bradenham Hall, Hartley’s inspiration for the setting of the Go Between – on 26 June. For Leo that would be 99.9°F – enough, maybe, to make Ted and Marian decide not to bother that afternoon. And the potting sheds and greenhouses – even shaded by Atropa Belladona would have been even warmer.

Too darn hot

It goes without saying that if it is too hot for sliding down haystacks and spooning it is probably too hot for sitting in a four hour exam board or writing a thesis. We now routinely see temperatures far beyond the expectations of people who designed our buildings and campuses, and this is to the detriment of the people who work and study in them.

Over the past few years universities have reacted in the way universities usually do to external crises: offered guidance. The University of Nottingham has ideas about the way you should use windows and blinds, the University of York asks you consider light, loose, fabrics, UCL wants you to take more frequent breaks and even cancelled a couple of open days, the University of Bath limited the operation of campus services and urged you to stay at home if it was more comfortable for you. The University of Warwick urges you to stay hydrated.

This is generally well-intentioned, public-facing, advice. We know informally that staff have been encouraged to use air-conditioned spaces (like lecture theatres and cafes) to work, that providers have been flexible around attendance for those who are more comfortable at home, and have taken extra measures to support vulnerable staff and students.

But – in a nutshell – buildings in the UK are not designed for this kind of heat. Passive measures to address localised heat build up – things like external passive shading, ventilation and circulation measures, high albedo external surfaces, purposeful landscaping and vegetation – are rare. And air-conditioning retrofits, while becoming more common, are expensive and energy intensive.

Of course, the heatproofing of the campus, while expensive and complex – feels a lot more achievable than heatproofing the homes and halls in which staff and students live and work. Campus adaptations can help to address ill health, and reduced productivity or capacity to study, but they only represent a part of the wider life of those associated with universities.

Come for the cool air, stay for the education

The kind of adaptations needed to keep the campus livable in hot weather are gradually migrating from a portfolio focused on measures to address climate change, to the world of business continuity planning and climate resilience. Extreme heat has entered the risk register – and while global climate concerns are undeniably important, the day-to-day impacts are hyperlocal in nature.

The action starts with the information you hold about your estates – be this qualitative (survey responses and complaints) or qualitative (a digitised estates information system, or local and regional climate data and projections). This will help you identify particular hazards and hotspots on campus – for example a glass-walled atrium or lecture theatre, underventilated staff offices, or elevated overnight temperatures in residences.

Building and maintenance project plans have expanded in recent years to include references to climate adaptation standards (such as BREEAM or GRESB) allowing universities to learn from practice and expectations elsewhere. There is also a growing national and local government interest in developing resilient public-facing spaces, but there is room to go further.

Certification and cost

The UK Green Building Councils’ Climate Resilience Roadmap calls for public investment in addressing climate hazards in new and existing buildings: including for what should be basic mitigations like ventilation and shading. It also recommends changes to the venerable Energy Performance Certificate (or, as is preferred for non-domestic properties, the Display Energy Certificate) to recognise the need for adaptations to address extreme heat, or the launch of a Climate Performance Certificate.

Until then, the sector’s buildings are classified using an EPC or DPC. The latter is more focused on real world performance (the former is theoretical performance based on building attributes) but both, in addressing energy usage only, only gives a part of the resilience picture. One commonly wished-for adaptation is the installation of air conditioning – in most cases this would increase the energy consumption of a building and offer a lower EPC or DPC rating unless this was mitigated in other ways.

EPC and DPC certification levels represent one part of this growing area of concern that we can look at in public HESA Estates data. Here, anything above D is better than would be expected for the use of a building of that type, with E to G being less energy efficient than might be expected. Here’s how that looks at your provider:

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These charts come from the HESA Estates record, published today. As a non-compulsory data return (in England, Scotland, and Northern Ireland) coverage is limited and data quality often uncertain – for the 2024-25 academic year just 139 of 304 eligible providers chose to make a return. It is the only national data available on the condition or environmental performance of the UK’s higher education estate.

Can’t we just have air conditioning?

Here’s where all the energy needed to run university buildings comes from:

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You may well ask why your choice of power source is pertinent to dealing with heat. Again this comes back to air conditioning – if you want it (and many do) you need energy to run it, and energy is (given various geopolitical travails) about to become very expensive. If you want a chance at conditioned air, you need cheap energy: and the cheapest on a long-term basis is provider-owned renewables.

As a nation we’ve gotten better at using renewable energy to supply electricity to the national grid – over the past week more than 50 per cent of our electricity came from renewable sources, and as I write the largest single source of grid power is solar. This is something which will hopefully mitigate some of the price increases coming down the line. But air-conditioning remains an expensive, longterm, choice – and there are other things that can help for a lot less.

Passive measures

If you are out and about on a sunny day (and especially if you share my northern heritage) it feels like the most natural thing in the world to head for the shade – and if there are no indoor options available the finest shade can be found under a tree. The same applies for buildings. Direct sunlight heats the structure of a building – bricks, glass, concrete, roof tiles – and these elements heat the inside, often for hours after the direct sunlight has gone. Dense foliage from fast-growing trees is a cheap (far cheaper than altering and adapting the building) and renewable way to cool down, all while lowering pollution. And, with appropriate maintenance, it looks fantastic.

Unfortunately this isn’t a straightforward remedy for everyone. Many campuses, in city centres for example, do not have the space for this kind of planting. Here, instead, we find design elements, canopies, sails, green roofs, and reflective treatments for windows and surfaces as the default – using the building itself to provide shade. This is more expensive upfront, and retro-fitting isn’t as effective as solutions designed into the fabric of the building from the start.

Likewise, passive natural ventilation (where cool air is taken in near the ground and warm air ventilation), perhaps aided by measures like ceiling fans, is something that really needs to be designed in rather than added later.

One measure that can be added to nearly every kind of building is insulation. In the UK we usually think of this as a means of staying warm in winter. It’s basic physics really – insulation slows heat transfer between the outside and the inside of a building, making whatever measures you are using to adapt the temperature indoors more effective.

Planning for what we have, not what we want

We’ve always seen the occasional summery hot day or hot week in the UK. But in recent years the frequency and severity of both has risen, and they creep into the academic year in late spring and early autumn. To be clear, the temperatures this summer (and in recent years) are not remarkable by global standards, but our infrastructure – and our campuses – are not well adapted to deal with them.

Mitigation measures are available, and should be taken. There is very little point in assuming because you personally are fine with the heat that there is no need to act to help those who are not. Harking back to the legendary summer of 1976 tends not to focus on the pressures on the health services, the droughts, and the higher than usual death rate – and these are for lower temperatures than what we are experiencing now.

We’ve learned and adapted to previous changes in the UK’s prevailing weather. But what we did historically is not enough to get us through what we are experiencing and we are continuing to experience. Even the most enthusiastic projections around the mitigation of climate change see another 50 years of summers like this and worse.

At this point, the past really is a different country.