Can you put a boiler in a loft? We take a look at the pros, cons, costs and more

Installing a boiler in a loft is becoming an increasingly attractive idea among homeowners investigating how much is a new boiler, for a whole range of reasons. As well as saving space in areas such as kitchens or utility rooms, it can also help reduce noise.

However, there are some important challenges to consider as well, particularly with regards to protecting the boiler against extreme temperatures and ensuring there is enough access for checks and maintenance.

We asked the experts to explains the pros and cons of a boiler in a loft, what types are best suited to this location and what are the regulations surrounding the job?

As well as it being vital to consult a Gas Safe registered heating engineer if you're considering a boiler in loft scenario, here's what else they recommend.

Boiler in loft – yes or no and which type is most suitable?

It is possible to install a boiler in a loft and there are certain benefits to be gained from doing so, especially with regards to saving space, reducing noise and improving the aesthetics of your home.

"All of our wall-hung domestic boilers are suitable for use in a loft," confirms Richard Farrow, senior product manager at Ideal Heating. "However, the system would probably need to be sealed (using a combi or system boiler), as an open-vent system would require the header tank to be located higher than the boiler, which could be difficult in a loft."

There must also be sufficient access for checks and maintenance. This will include proper, safe, access to the loft, which means a ladder with a handrail, boarded flooring leading up to and surrounding the boiler and adequate lighting. The boiler itself must also be hung on a brick or timber wall to ensure it is supported properly.

Installation requirements

There are plenty of considerations, including safety rules to take into account during the process of putting a boiler in a loft.

The boiler will need gas, water and electricity terminals installed and each of these will need isolation points so that they can be switched off safely. A vent will also have to be installed so that the combustion gases can be removed safely from the property and there will need to be proper access to the boiler so that maintenance can be carried out on it.

“While it may be tempting to put a boiler in your loft to save space downstairs, there are regulations that may restrict you from doing so for safety reasons," confirms Jack Cole, a heating expert at MyBuilder.com.

“There must be sufficient safe space in your loft to be able to fit your boiler, as well as your wall being able to hold the weight of your boiler. Your loft must also provide stable and secure flooring so you or a professional can safely carry out maintenance work on your boiler if needed.

“If you move your boiler into your loft, you have to ensure there are safe and adequate access points, including a fixed ladder, walkway, and lighting," explains Jack. "These items will help lower the risk of causing harm to you or your loft with a boiler in it."

Pipework connected to the boiler may also have to be resized or extended and this will add to the costs of installation.

Jack Coles

Jack Coles is a heating expert at MyBuilder.com, one of the most reliable ways homeowners can hire trusted tradespeople

Regulations regarding boiler in loft

There are a number of regulations governing boiler installation in the UK, all of them covered under building regulations. These regulations require all boilers to be installed by Gas Safe registered engineers, located in safe locations with proper flue placement and meeting a set of minimum energy efficiency standards.

"In principle, the regulations for putting a boiler in the loft are the same as fitting the boiler elsewhere in the house," says Richard Farrow. "Additional requirements for putting one in a loft are more related to health and safety issues such as ensuring there is a suitable loft ladder, the floor is boarded, and sufficient lighting is provided for a safe installation."

Regulations state that installations will require a high-efficiency condensing boiler (this requirement was set in 2005) and the engineer installing the boiler will have to notify the local authority after the installation, after which they will receive a compliance certificate.

Building regulations also require the boiler flue to be placed away from windows, doors, balconies, and public walkways, in accordance with specified minimum distances, which are dependent on the location of the boiler.

The regulations state that there must be at least 600mm between the boundary line of the building and the end of the flue and the flue must be positioned away from footpaths and walkways. It must also be 300mm away from windows or air vents and 1,200mm away from doors.

Flues must also be 25mm away from any guttering or drain pipes and at least 300mm above ground, roof or balcony levels. They should also be positioned 600mm away from neighbouring properties.

And finally, boilers must meet minimum energy efficiency standards, usually requiring a high-efficiency condensing boiler with an A rating. The updated boiler regulations of 2022 require that radiators must operate at a temperature no higher than 55°C.

Pros and cons of putting a boiler in the loft

Pros of boiler in loft

"Putting a boiler in the loft moves it out of the way and does not take up useful living space, such as a kitchen wall cupboard, or valuable space in utility rooms, when space is limited," says Richard Farrow. "Fluing is usually easier too," he adds.

Another benefit of putting a boiler in a loft is that this location will help to prevent noise from the boiler reaching the rest of the house. Concealing the pipes in the loft will also help to improve the aesthetics of other locations in the house, and may improve maintenance while also reducing the risk of accidental damage to the pipes.

Cons of boiler in loft

When it comes to the downside of putting a boiler in the loft, you may find if you're considering moving an existing boiler, you won't have the right type.

"Installation is also less easy as the boiler has to be carried up into the loft," notes Richard Farrow. "It is not as easy to check on the boiler, such as checking the pressure gauge, as you have to go up into the loft. The pipework might also be longer, which needs to be considered."

Temperature also needs to be taken into account as the extreme temperatures that a boiler might be subjected to in summer and winter may damage the boiler. However, in winter, the right loft insulation might be able to mitigate this to a certain extent. in summer the loft would need enhanced loft ventilation to keep the space relatively cool in the face of rising temperatures.

You'll need to ensure you have the right loft boarding and access arrangements in place and if height or space is limited, it might mean a flue is more difficult to install. This, again, will increase the cost of installation.

The increased distance from the water supply to the boiler might also mean a delay in the boiler supplying hot water. Furthermore, this will also mean extended pipework, which again could increase costs.

Given that the boiler will be installed higher up in the building, this also means that the pressure will be lower. If the existing mains water supply is already low pressure, that might adversely impact a boiler in the loft.

Cost of installing a boiler in loft

The cost of installing a boiler in the loft depends on a range of factors, such as the type of boiler, the layout of the property and the pipework involved. It will probably be more worthwhile doing this when a boiler needs replacing, rather than moving an existing boiler – unless of course you are planning on a complete home renovation or extension, in which case it may be wise to do it now while you are already being disrupted. Find out more about when to replace a boiler as a starting point.

The average cost for installing a new boiler in a loft typically ranges between £1,200 and £1,400 on average. However, this excludes any additional work, such as installing additional extensive pipework.

The key factors involved in installing a new boiler in a loft includes the choice of boiler, the distance between the new boiler and the existing pipework (and whether any new pipework is required), improved access to the loft, and flue installation.

In contrast, if you choose instead to move an existing boiler into a loft, the cost will range somewhere between £300 and £600.

Wondering if you really do need to install all the extra boarding and loft access to put a boiler in a loft? Don't cut any corners, warn the experts as it's simply not worth it. "Failure to meet these requirements falls short of British standards and may put you and your home at risk," explains Jack Coles. "A quick visit from a local Gas Safe engineer will help you understand if you can move your boiler into a loft and an estimated cost to do so."

Of course, if you are considering replacing or moving your boiler, you may be in the market for a completely new heating system in which case you could might want to look at more sustainable options such as an air source heat pump. Find out what the gas boiler alternatives are before you make your final decision on putting your boiler in a loft.