Does it make sense to get an air conditioner in the UK?

Once upon a time, the very notion of air conditioning was an anomaly to the residents of Great Britain. What a waste of money to have such a monstrosity installed in a building, particularly in one's home! It would only get used for, what, three, four days out of the year? However, times have changed, and temperatures have changed with them.

- Helen Coffey, The Independent

In July 2022, the UK experienced its first recorded temperature above 40C; the Met Office warned this week that hitting this level of heat is now 20 times more likely than it was in the 1960s. And as the climate crisis continues to reshape our idea of what constitutes a "normal" summer, things are only going to get hotter. More than 55 per cent of homes in the UK are already at risk of overheating, according to the UK Green Building Council (UKGBC), whose UK Climate Resilience Roadmap, providing recommendations for the industry and policymakers to "increase resilience to climate hazards", was launched this week. The housing most prone to overheating is, perhaps counterintuitively, new builds—they're better insulated and designed to be more energy efficient in winter, but more prone to overheating in summer than existing Victorian houses or older buildings because of poor ventilation.