Floor insulation helps reduce the amount of heat that escapes through the floor of your home.
It adds a layer between your home and the cold ground, making rooms feel warmer and more comfortable, especially in winter. It can also lower your energy bills by cutting down on how much heating you need.
Generally, you only need to insulate a ground floor. If you’re on an upper floor, floor insulation isn’t usually necessary. However, if any part of your floor sits above an unheated space (eg a basement), it might still be worth insulating it to reduce heat loss.
The Warm Homes Plan is set to invest close to £15 billion in improving the UK’s homes to cut energy bills.
For people on low incomes, there’ll be fully funded government support to install insulation.
There’ll also be low and zero-interest loans available for homeowners regardless of income.
We’ll update this guide when we know more.
For more information, read our blog on what the Warm Homes Plan means for you.
Insulating your floor involves adding material to the construction of your floor. This material is designed to slow down heat loss. It can be installed either above, below, or between layers. The type of insulation material and how it’s installed depends on how your floor is built.
This guide will help you figure out what type of floor insulation is suitable for your home.
Here are some common floor types and their characteristics.
Many homes (particularly those built from the 1950s onwards) have a ground floor made of solid concrete.
If your home was built since the early 2000s, it’s likely the floor already includes insulation as part of the construction.
If not, concrete floors can be insulated if they’re being replaced, or by laying rigid insulation boards over the top.
Some older homes have solid floors made from flagstones, tiles laid over earth, or lime-based material. These floors typically have no insulation. Insulating them can be more complex and may require specialist advice, especially in heritage properties.
Suspended timber floors are commonly found in homes built between the 1850s and the 1950s. They are typical in Victorian and Edwardian properties. You probably have this type of floor if there are air bricks or ventilation bricks on the outside walls of your house below floor level.
If you do have air bricks in your walls, don’t block these up. They help ventilate the space under your floor and stop your floorboards rotting.
Have a basement or cellar beneath your house that you can get into safely? Look down there to see what type of floor you have. If the floor is a suspended wooden floor, you’ll probably be able to see wooden joists and the undersides of the floorboards.
Don’t have access to the space underneath your house? You’ll need to lift a corner of your carpet, laminate or other floor covering to check.
To insulate suspended timber floors, insulating materials like mineral wool or rigid foam boards are installed between the floor joists beneath the floorboards. If there’s sufficient space below the floor, installers can access the area by crawling underneath. Otherwise, the floorboards may need to be lifted to fit the insulation and then replaced.
Other floor constructions, such as concrete suspended floors or hybrid designs, may require specialist assessment to determine the most effective insulation approach.
Benefits include:
This depends on your floor’s construction and your DIY ability.
It may be possible (and more affordable) to insulate a typical suspended timber floor yourself. However, only attempt this if you’re confident in your skills, as it can be more complex than it looks.
Not sure what kind of floor you have or how to approach the job? Seek professional advice or hire a qualified installer to ensure it’s done safely and effectively.
For example: you need to make sure you have adequate ventilation and moisture control to avoid damp problems. You always need to make sure there are no gaps in the insulation as they can dramatically reduce its effectiveness. Professionals can help you with this.
Depending on the work you’re doing, you might need other tradespeople too. For example: you might need an electrician to help you move plug sockets if you’re insulating a solid floor.
If you’re looking for someone to insulate your floor, you should find a qualified installer, for example, an installer who is a member of TrustMark. TrustMark is a government-endorsed quality assurance scheme for work that you have done in or around your home.
It’s also a good idea to check whether the installer is a member of a relevant trade body such as:
Also, you should check if the installer is registered with a relevant Competent Person Scheme (CPS). You can check for CPS registered tradespeople on the UK Government site.
Before agreeing to any work, ask:
Where possible, compare quotes and methods from at least three installers to get the best deal and right solution for your home.
Keep a copy of your paid invoice and, if possible, take a few photos during the installation. Floor insulation will be hidden once installed, so photos can be useful if you need to provide evidence for a new Energy Performance Certificate.
If you want to insulate your floor as part of a bigger refurbishment job, ask your existing builder if they’re able to do this. You could co-ordinate them with a specialist if necessary.
If you’re replacing a significant portion of a floor, you’re legally required to insulate it to meet current building regulations. These rules are in place to improve energy efficiency by reducing heat loss through the floor. This helps improve how your house manages the overall transfer of heat.
Even if you’re not replacing the entire floor, the work must still comply with the relevant building regulations for your region. While most professional installers will handle this process, the legal responsibility ultimately rests with you as the homeowner.
The U-value measures how quickly heat passes through a material. The lower the U-value, the better the insulation. The required U-values for floor insulation vary by region. The U-value should be displayed on the insulation packaging.
To meet these standards, you’ll typically need one of these two options:
If you’re replacing 50% or more of a floor, you must insulate to these standards, even if insulation wasn’t part of your original plan.
For detailed guidance and to ensure compliance, contact either your local Building Control Office or Building Standards Department (if you live in Scotland).
Find your local Building Control Office in:
Find your local Building Standards Department in:
They can provide region-specific advice and help you avoid costly mistakes or delays.
A typical suspended floor installation could cost you between £1,400 and £2,500, depending on your house type. Solid floor insulation could cost considerably more.
How much floor insulation costs varies depending on how big the ground floor you’re insulating is and with what material you’re using.
Have a suspended floor? You’ll also need to think about how easy the floorboards are to lift and replace as this can affect the price.
Depending on where you live, you might be able to apply for financial support to help towards the cost of floor insulation.
Find financial support for home energy efficiency improvements.
Looking for other ways of keeping your home warm and save money? Our reducing home heat loss hub has information about other types of insulation and other energy efficiency measures.
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Last updated: 19 May 2026
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