If you live in an older home, you might be wondering if an air source heat pump is a practical option for heating.
Many homeowners worry their old house will be too costly to run a heat pump or simply unsuitable for one. However, that’s not always the case. In fact, many homes, even those over 100 years old, have successfully been fitted with heat pumps. The decision isn’t black and white—there are several factors to consider to determine if a heat pump is both efficient and cost-effective for your home.
A Brief History of Domestic Heating
Before the advent of modern heating systems like boilers and heat pumps, homes were primarily heated by fire, otherwise known as a hearth. These would be situated in the center of the home and smoke would escape through a hole in the roof. Over time, this evolved into fireplaces built into walls with chimneys, which became common in the 1600s. By the 1800s and early 1900s, gas and electric heating methods began to emerge, with portable heaters and radiators becoming standard.
In the late 20th century, renewable heating options started gaining popularity, with air source heat pumps first introduced in homes during the 1960s. In recent years, they’ve become increasingly common in the UK, as homeowners seek energy-efficient and environmentally friendly solutions.
Factors to Consider Before Installing a Heat Pump
Wall Insulation
Older homes, especially those over 200 years old now, were not built with modern heating efficiency in mind. Many were constructed with single solid walls, which are prone to damp and poor insulation. The introduction of cavity walls in the early 19th century were quite different to those we know now. While they offered better protection from the elements, they were not designed to have insulation so were quite narrow.
Upgrading the wall insulation for both these types would be beneficial even if you’re not considering a heat pump. Proper insulation will prevent heat from escaping, allowing any heating system to work more effectively and keeping your home warm at a lower cost.
Loft Insulation
In 1965, the UK government made its first regulation for home insulation, requiring just 28mm of loft insulation for all new homes. By the 1990s it was recommended that 200m depth be installed, and by 2003 it was 270mm. Upgrading loft insulation is one of the most straightforward ways to improve your home’s energy efficiency, and it can also boost your property’s value.
Many older homes have areas of flat roof or have dormer windows, while not being as straight forward, should still also be considered when deciding to insulate.
Building Materials
The construction materials used in your home’s walls also play a significant role in determining heat retention. Older homes often feature cavity walls with two layers of brick masonry, while modern builds instead use concrete blocks. It’s easy to tell whether your home has cavity or single brick walls just by looking at the pattern. Cavity walls have brick laid length ways, while solid use half bricks in the pattern.

Another common material for older homes is stone, rough uncut ‘rubble’ stone or dressed cut ‘ashlar’ stone. Insulating stone walls can be difficult and requires additional care, whether lining internally or externally. Other types of older building materials include cob and timber, these are less commonly seen but inherently have better insulating properties to them. Solid walls are known to be worst for heat loss, whether brick or stone.
Windows
Double glazing was invented in the 1930s by American Charles Haven, but it wasn’t until the 1970s that it would become commonplace in the UK. So, many homes built before then will only have single glazing if not already updated. It’s easy enough to upgrade to double or even triple glazing, and this greatly improves the home’s energy efficiency, but for listed buildings you may sometimes require planning permissions. It can often be more sustainable to instead repair windows and install secondary glazing, and this also does not require planning permissions for listed buildings. Secondary glazing is the installation of a second layer of glass inside your existing windows, this is cost effective and still improves your efficiency.

Home Size
Understandably, the size of any home plays a large role in heat loss. The bigger the space the harder your heating has to work. More bedrooms of course require more radiators, and the size of each room determines the size of said radiators.
While the concept and basic technology has existed for centuries, underfloor heating as we understand it today, has made a great difference on heating larger rooms more evenly as it spans the surface area. Underfloor heating using pipes only became commonplace by the 1980s, and even then a lot of newer homes still don’t have it. When combining this with all the right insulation, you stand a better chance at keeping a larger home warmer.
Heating System Type
Many older homes are often “off the grid,” meaning they don’t have access to the gas mains and instead rely on either oil, LPG, or electric heating. All of these options can be quite expensive, especially when you consider all of the above factors in terms of how efficient your home is at retaining heat. A good question to ask is “What is the most energy efficient option for my home?” instead of if an air source heat pump is suitable. A good installer will always do right by you to ensure your home is heated in the most efficient and cost effective way, even if this isn’t by an air source heat pump.
If your home is ‘off grid’ from gas, it at least means converting to a heat pump would be easy enough as it’s powered by electricity. If you also happen to have solar panels on your property, this further benefits your pockets for saving money and not relying on the grid for power.

The Importance of a Survey
With any home a thorough survey is important, but even more so with older homes. We need to look at all the factors listed above to determine how efficient your home is at retaining heat.
The surveyor will take measurements and photos of every room, including photos of existing radiators, plumbing and heating, as well as look at all insulation and materials used in the construction of your house. They will also need to look at the energy performance certificate, but if you don’t have a valid EPC then they can apply for a new one based on all the information gathered.
Opting for a company that handles both the survey and installation ensures better communication and more accurate results. A knowledgeable installer can guide you through the entire process, helping you determine whether your home is heat pump-ready or whether additional upgrades are needed first.
Heat Loss Calculations
After the survey, your installer will conduct a heat loss calculation, a critical step in determining how efficiently your home retains heat. Again, if this process is conducted in house then you are more likely to get an accurate result, one wrong detail input can make a big difference.
To give some perspective, the heat loss difference between a modern 2 bedroom house compared to one built 150 years ago is dramatically different. The size of a heat pump usually required too, is much larger if the heat loss is greater. With this calculation it can be determined if your old home truly is suitable for a heat pump or not, so it’s important it’s done correctly.
If for example, your older home is single brick, single glazing, and with multiple bedrooms, then we would recommend looking to upgrade your insulation before installing a heat pump. Grants such as the Great British Insulation Scheme (GBIS) can help offset the cost of improving your home’s insulation. With these upgrades in place, even older homes may become suitable candidates for heat pumps.
The Future of Domestic Heating
We’re now in an era where we use our heating year round and our homes are the hottest they’ve ever been, this comes with an environmental cost. Renewable options are becoming increasingly popular as well as encouraged by the government, the goal to reach net-zero is becoming an ever closer reality for the UK. Eventually fossil-fueled boilers will be phased out, so even if your old home isn’t currently up to standard with its heat loss, it would be smart to start taking the right steps towards making a more energy efficient home
Once your home has all the necessary insulation to improve its heat loss, you can look towards government incentives, like the Boiler Upgrade Scheme (BUS). This funding is available to assist homeowners in transitioning to renewable heating options like air source heat pumps, so that the country as a whole can help towards lowering carbon emissions.
So, Is Your Home Too Old For a Heat Pump?
The short answer: it depends. As we’ve discussed, several factors influence whether a heat pump is the right choice for your home and you simply won’t know without booking a survey. Improving your home’s insulation and overall energy efficiency, however, can make it more heat pump-friendly. It would be wise to make use of the government grants while they’re still widely available, this can be easily arranged by your installer on your behalf.
The most important step is to find a knowledgeable installer who will assess your home’s unique needs. A reputable installer will guide you toward the most efficient heating option—whether it’s a heat pump or another system—and ensure that your home stays warm without unnecessarily inflating your energy bills.