Written by Tatiana Lebreton Updated on 17 October 2023 ✔ Average UK summer temperatures could reach 27°C by 2050✔ Less than 5% of UK homes currently have air conditioning installed✔ In 2022 the UK recorded 2,803 excess deaths from the heatGlobal warming is making heatwaves more frequent in the UK, and is gradually raising the average temperature. According to the Met Office, since the 1980s global temperatures have increased by 0.2 Celsius (°C) per decade.So, it’s time to ask: is the UK prepared for summers that regularly reach 35 °C?Recent UK heatwaves seem to indicate that we aren’t as prepared as we should be – there were a little under three thousand excess heat-related deaths recorded in 2022, according to the Office for National Statistics.It might be time for the UK to make home air conditioning the norm, the same way many hot countries such as Greece already have. But there are also other things we can do first, to mitigate the effects of heatwaves.In this article, we’ll explain how global warming is changing UK summers, and explore whether air conditioning is the solution for Brits coping with rising temperatures. What's on this page? 01 Is global warming making the UK too hot? 02 Is air conditioning a viable solution in the UK? 03 How much does air con cost? 04 How expensive would it be for every UK property to have air con? 05 Would air conditioning be expensive to run in the summer? 06 Summary Is global warming making the UK too hot?Global warming is making UK summers hotter and dryer and the winters milder and wetter, according to the Met Office. And it’s getting worse as the years go on.In fact, ten of the UK’s warmest years on record have all happened since 2002 – a phenomenon that the Met Office directly links to climate change.The UK also saw record-breaking temperatures in 2022. During the summer, temperatures reached above 40°C for the first time. The average annual temperature was also higher than 10°C for the first time on record.How hot will UK summers be by 2050?By 2050, UK summers could reach an average of 27°C, with heatwaves happening every other year.The Met Office estimates that by 2070, UK summers could be between 1°C and 6°C warmer. That means the average summer temperatures could be around 20°C to 28°C, instead of the current 19°C to 22°C.And by 2100, UK temperatures could reach 35°C in summer every year, according to a 2020 study, published in Nature Communications. To compare, the UK currently only reaches 35°C every five years.Why are hot summers in the UK so dangerous?Hot summers are particularly dangerous in the UK because the country isn’t prepared for them, which means they pose a major risk to public health and safety.The 2022 heatwaves alone are estimated to have caused a total of 2,803 excess deaths (this refers to deaths above the normal average during a crisis) in people over 65.But why is the UK’s population so vulnerable to heat? Well, it partly comes down to a lack of knowledge on how to keep our homes and ourselves cool during hot spells.UK homes are also not built to stay cool. Most homes in the UK don’t have external shutters, which prevent heat from entering the home and are very common across southern Europe, or any air conditioning.Unlike homes in other European countries, a lot of UK homes – a little under half in England and Wales – have low energy efficiency ratings, mainly due to poor insulation. Proper insulation is good for retaining heat in the winter, but it can also keep homes cool in the summer.High temperatures can also be dangerous because they can damage the UK’s infrastructure, which isn’t built to withstand them. In the summer of 2022, for example, roads and airport runways melted, and some rail tracks buckled due to the heat. Is air conditioning a viable solution in the UK?Air conditioning might not be a viable solution for all properties in the UK, because our homes aren’t designed to accommodate it. This means that homeowners will need to pay to have additional work done before they can install it.UK homes are typically poorly insulated – and the older they are, the worse their energy efficiency is, according to the Office for National Statistics.Homeowners that already live in well-insulated properties might find that air conditioning is a simple solution to the increasing temperatures.It’s also worth bearing in mind that, if your home isn't energy efficient, it’ll be more expensive to use air conditioning. Without good insulation, the cool air from the air con will escape your house quickly, meaning you’ll have to use more energy to keep the property cool.And the more energy we use, the more carbon emissions we create, since around 62% of our electricity still comes from fossil fuels. This makes using air con in poorly insulated homes particularly bad for the environment.Plus, air conditioning units can make hot spells feel more intense, since they release hot air back outside through their ducts. This is especially problematic for crowded cities, which globally are already 10°C to 15°C hotter than rural areas.This can lead to a vicious cycle. The climate keeps warming, so we use aircon to stay cool, which creates more emissions and speeds up global warming.One low-carbon way to cool a house is by using a portable heat pump, which despite the name, can heat as well as cool rooms.Is UK housing suitable for air conditioning?Some UK properties will be suitable for air conditioning, but other older, poorly insulated properties won’t be a good match.This is because UK homes weren’t built with air con in mind. In fact, one in six homes in the UK were built before 1900, back when air conditioning didn't exist yet.Homeowners living in a typical UK terraced house will also have limited options as to where to install the external components of an air conditioning system, since there will be neighbouring properties attached to each side of the home. This can also be an issue if you live in a block of flats.Most UK homes are also completely unsuitable for ducted air conditioning systems, which are very common in US homes, and involve cool air travelling through a vent system. That’s because many UK homes have brick walls, with small air cavities that can’t accommodate these ducts.Another issue is adaptability. A professor at University College London’s Energy Institute has pointed out that the UK’s “wet heat” heating system, where hot water is sent into radiators, can’t be converted into a cooling system.In the US, most homes have “dry heat” systems that can convert into air conditioning systems in the summer. Hot air is distributed through the house through ducts (passages in the wall or ceiling) – and in the summer, they circulate cool air into the house. How much does air con cost?A split air conditioning system – one that has an outdoor fan and an indoor unit – costs roughly £1,200 per room (including installation).Wall-mounted units are usually the simplest and cheapest option. But, you can also opt for fan-convector units, which cost around the same, and look similar to radiators.Another option is to install a ducted air conditioning system, where cool air goes through a passage in your walls. However, this is the most expensive system to install, and can cost around £3,000 per room.You can also buy portable AC units to use in one room, which can cost anywhere between £50 and £500 upfront. But since these units don’t need to be installed – you simply plug them into the wall socket – you can avoid installation costs.The downside is that portable air conditioning units make a lot of noise, and you need to run a small duct through the window to expel the heat the unit generates.This also makes them less energy efficient than split or ducted air conditioning systems, since having the window open will also let some of the cool air escape. How expensive would it be for every UK property to have air con?It would cost the average three-bedroom house around £6,000 to install a split air conditioning system in most of their rooms. A ducted air conditioning system, on the other hand, could cost up to £14,000 to install in an entire property.And the more rooms you need to cool, the more expensive it would be.But how expensive would it be to install home air conditioning on a nationwide scale? Well, there are around 28 million households in the UK – with over 90% of them living in houses or flats, and fewer than 5% of them having air con.If we take £6,000 as the average cost of air conditioning, it would cost over £168 billion to fit every UK home with air conditioning. Would air conditioning be expensive to run in the summer?Running air conditioning can be expensive during the summer because it uses electricity, which is three times more expensive than gas. An air conditioning unit that uses around 900 watts (W) will cost roughly 31p per hour to run, based on an electricity rate of 34p per kilowatt hour (kWh). That’s around £1.83 per day if you run an aircon unit for six hours a day.This means air con can get expensive if you have it on all the time, or if you choose a model with a low efficiency rating, which will use more electricity to run.And as a reminder, the more air conditioning units you have installed, the higher your running costs will be.The running cost will also be affected by the size of the room you are trying to cool and how insulated it is. The less insulated your home is, the more expensive the air con will be to run. SummaryThe UK is already witnessing the effects of global warming, with hotter summers and heatwaves happening more frequently. We can no longer consider ourselves a ‘cold’ country, and we need to adapt our homes and buildings accordingly.Installing air conditioners in homes is one solution – but there are more sustainable solutions we could adopt first, such as making sure UK homes are designed to stay cool.This could include fitting homes with external shutters, installing better insulation, and building houses with light coloured-materials.If you’re still interested in sustainable tech to cool your home this summer, you could look into air source heat pumps. This low-carbon heating system can replace gas boilers, and also act as an air conditioner in the summer. Written by: Tatiana Lebreton Tatiana has written about multiple environmental topics, including heat pumps, energy-efficient household products, and solar panels. She is dedicated to demystifying green tech to make eco-friendly living more accessible.