With more than two-thirds of the UK in drought, the historic stone bridge over Baitings Reservoir is exposed due to falling water levels across the country. Image from August 13, 2026.
Historically, construction projects in northern Europe have prioritized heating properties. But in the face of rising temperatures, more homeowners are considering installing air conditioning units.
While 88% of homes in the United States have air conditioning, only around 3% of properties in the United Kingdom have the equipment.
What are the main problems?
Installing an air conditioning system in an already built house will probably cost more than £6,000 (around R$44,000) to service the entire property.
It will also be necessary to run pipes through the walls, which may require renovations later. Running costs range from a few hundred to a few thousand pounds per year depending on the size of the property.
It is important to remember that electricity in the United Kingdom costs double the rate in the United States, where the use of air conditioning is much more common.
Typically, installing an air conditioning system involves an external unit, called a condenser, and a fan unit installed on the wall or ceiling. The two are connected by pipes.
These pipes transport the refrigerant from the outdoor unit to the indoor unit, which cools the air. The process can be reversed during the winter to provide heating. This type of equipment is known as a split system.
You also need to consider construction and permitting rules. Condenser units produce noise and can compromise the appearance of properties.
In general, it is not necessary to obtain authorization to install equipment when the units are discreetly positioned. This, however, can be more difficult in apartments, as the noise can disturb neighboring properties.
In these cases, authorization may be required. Therefore, it is important to check local regulations before installation. Air conditioning also needs to follow different construction standards, including those related to safety.
Installation in historic properties
Another important factor is the age and type of construction of the property.
Historic buildings often have thick stone walls and a large thermal mass, which means they take longer to heat up or cool down.
Many of them are designed to be airy and well ventilated, which helps control problems such as excess humidity.
On the other hand, this means that there is greater air circulation outside the property, making the air conditioning need to work harder. Additionally, high ceilings increase the volume of air that needs to be cooled.
Installation may also require specific authorizations and be more complex and expensive.
Another point to consider is the humidity level. Depending on the air conditioning system used, it can increase, which can be especially problematic in historic buildings.
When the air temperature drops, as happens during cooling, the relative humidity inside the room increases. Therefore, it may be necessary to use a dehumidifier.
What about portable devices?
Another option is portable air conditioners. They concentrate all components in a single machine.
However, these devices are designed to cool small spaces and tend to be less energy efficient, which increases running costs.
They also need a duct to release the heat outside. Typically, this requires installing an opening in an exterior wall or window.
Leaving the pipe outside an open window can allow heat to enter the room and cold air to escape.
The installation of devices similar to window models common in the United States may also require consultation with the department responsible for urban planning to verify any restrictions.
Furthermore, these equipment require windows that open vertically, such as so-called sash windows. This type of window is not common in many modern UK homes.
When buying an air conditioning unit, you also need to be aware of possible scams. As with so-called "miracle" heaters, there are refrigeration products sold at very low prices that make exaggerated promises.
Environmental consequences
The environmental impact is also a long-standing concern.
In the past, air conditioners used CFCs, substances that harm the ozone layer, such as refrigerants. These compounds, however, are no longer used in equipment currently sold.
Even so, the devices contribute to the so-called urban heat island effect, which makes cities hotter.
This happens because the heat removed from the properties is released by the condensing unit into the surrounding air. This effect can contribute to making hot flashes even more intense.
Carbon emissions also vary depending on the origin of the electricity used.
In France or Portugal, where the electrical matrix is largely composed of low-carbon sources, such as nuclear, hydroelectric, solar and wind energy, emissions would be lower.
In countries like Poland and Cyprus, which use relatively few renewable sources and have a limited or non-existent share of nuclear energy in their electrical matrices, emissions would be much higher.
What are the alternatives?
As heat pumps become increasingly common in new UK homes, one possibility for the future is to adapt these systems so that they also provide cooling during the summer.
Most of the systems already installed in the country were not designed for this. But if demand increases, it is likely that more equipment capable of performing both functions will be put on sale.
Another option, which can help reduce your energy bill, is to try to deal with the summer heat through so-called passive cooling.
This can be done by installing awnings, external blinds or structures to create shade over windows.
These alternatives have the lowest costs and may be easier to install. Furthermore, they help to reduce the temperature inside properties.
Traditionally, this was how buildings were kept cool during the summer.
Heat waves are one of the consequences of climate change. When evaluating different ways of dealing with heat, it is also important to consider how our choices can contribute to worsening extreme events.
This impact is especially relevant because heat waves affect older people and other more vulnerable groups more seriously.
