Why are radiators under windows?

UK Home Improvement

Why Are Radiators Under Windows?

There’s no doubt about it. Radiators are perhaps the most important appliance you have in your home.

For those who live in the UK, and other countries where the climate is inconsistent, they’ll know just how vital these metal machines can be. This is particularly the case during winter or the colder months of the year, as radiators allow warm air to be pumped into a property, ensuring people are not left cold or uncomfortable. 

With this in mind, it’s important that radiators are strategically placed in a room to ensure you can maximise their functionality. 

If you have a quick look around your property, you may notice radiators under windows. A radiator under a window is extremely common in many properties, and in this article, we’ll take a look at the question ‘why are radiators under windows?’ 

Read on to find out more.

History Of Radiators 

To understand why under window radiators are so popular, let’s first take a step back in time to examine how they became about in the first place.

While you’d be forgiven for thinking they’re a fairly modern invention, the history of radiators actually goes back centuries. 

In fact, the origins of a radiator can be seen in Ancient Rome. Back then, the hypocaust was the preferred method of central heating. A hypocaust was a system that involved a building producing and efficiently circulating hot air throughout a room to keep it comfortable. To achieve this, a hollow panel was built between floors where a furnace would release hot air which would heat the floor and thus the room as a whole. The hypocaust is actually closer to a modern-day underfloor heating system. The system was hugely popular, and as well as being used to heat private homes and the famous public baths across the Roman Empire, it was also utilised by people in ancient Korea and China. 

In terms of the modern radiator, we’d need to head to 19th-century Russia for when this was first invented. 

Russian inventor Franz San Galli created what is regarded as the first ‘proper’ radiator in 1857. From this starting point, Joseph Nason and Robert Briggs created systems in buildings that would combine steam with radiator systems to keep properties warm. 

The design progressed further as the century advanced, and by the late 1800s, the cast iron radiators had become a popular radiator type around the world, specifically due to being widely manufactured and sold by the American Radiator Company.   

Why Are Radiators Under Windows? 

Now we know the history of radiators, let’s focus on the question ‘why are radiators under windows?’

The main reason for this is because of the type of windows in a property. During the Victorian era, when radiators were becoming more and more commonplace, the coldest part of the room was typically around the windows.

This is because window technology was not as advanced as it is these days. There was no such thing as double, or even triple, glazing. This meant that every property had single glazing, which meant that cold air could fairly easily get into a building.   

Therefore, when radiators and central heating were installed in properties, it made sense to install them in the coldest areas of the house. 

So, when the hot air from the radiator rises, the cold air coming through the window is pushed against the hot, making the warm air circulation far more efficient. Placing radiators in the middle of rooms or away from windows wouldn’t heat a room up as quickly or effectively, which is why radiators under windows became the norm.

These days, most houses have double glazing as a minimum. This means that it’s no longer as essential to place radiators under a window. 

However, many older properties may still be designed this way especially if double glazing is a new addition. In contrast, newly built or more modern homes that are built with double glazing as standard may place radiators elsewhere as they’re better at retaining heat.   

The Best Places To Put Radiators

While it’s normal to see radiators placed under radiators, should radiators be under windows?

Well, ultimately, it’s up to you. 

However, we’ve put together a list of some of the best and most efficient places you could place radiators in different rooms of the house.


By clicking "Accept All Cookies", you agree to the storing of cookies on your device to enhance site navigation, analyse site usage, assist in our marketing efforts, and for personalised advertising.

More Information Accept All Cookies