First published: 21/02/2024 -

Last updated: 21/03/2024 -

Verified by our Editorial Panel

Insulating your home

A little more insulation and a little less heat loss is one of the best things we can do to reduce carbon emissions and save on energy bills.  

Insulating loft, walls, floor, windows and pipes can lead to significantly less heat loss. While the initial outlay can be expensive, improved insulation can help you achieve savings in the long term. So, check the Warm Homes Nest scheme to find out if you’re eligible for free home energy improvements, and for Welsh Government sources of support.  

What can we do?

From quick fixes to professional installations, consider these insulation measures depending on your budget and the kind of property you live in: 


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Draught-proof as much as you can

Reducing air leakage and air infiltration has a significant impact on the energy a home uses, provided you still have sufficient and effective ventilation. Draught-proofing strips are a useful and inexpensive option. They sit beneath windows and doors to help prevent cold air from entering, and warm air from escaping.

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Add insulation film to windows 

Window film gives an added layer of insulation and is a great option if double glazing isn’t affordable. It’s easy to fit and keeps heat in when it’s cold outside, as well as reducing heat from the sun for a cooler home come summer time. You could go one step further and add some thermal-lined curtains to keep rooms even warmer in the winter. 

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Hot water insulation 

Insulating pipes, tanks and radiators can be a quick, easy and affordable way to save money on energy bills. For example, you could fix reflector panels behind radiators on external walls, to prevent the heat leaving your home. Or add a jacket to your hot water cylinder if you still have one to help hot water stay hotter for longer.

Professional installation

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Window double glazing 

Double glazing involves two layers of glass with a gap in between, providing excellent insulation against heat loss. This efficient solution keeps your home warm in winter and cool in summer, making it energy-efficient all year round. Secondary glazing, which involves installing a “secondary” or fully independent internal window on the room side of the main window, can be a good alternative for traditional and protected buildings, where replacing windows is not a suitable option. It can also be less carbon-intensive to upgrade with secondary glazing than losing the embodied carbon in the existing windows.  


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Wall insulation 

Around a third of heat is lost through the walls in an uninsulated home, so with the right specification, design and installation method, wall insulation can be a good investment. Always consider any risks and seek professional advice first, as the wrong type of insulation can make it more difficult to keep a home cool and make condensation worse. See the Energy Saving Trust website for guidance on whether your property has solid or cavity walls, and what to do next. 

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Roof insulation 

Houses can lose up to 25% of their heat through the roof. Insulating the loft or roof is a simple and effective way to limit that loss and reduce heating bills. But think about materials. Like all building materials, insulation has ‘embodied carbon’ – that’s the CO2 associated with its manufacturing, transport, construction etc. Choosing materials with low embodied carbon reduces environmental impacts. 

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Floor insulation 

Usually only the ground floor needs to be insulated, so for those of us living in a house, bungalow or ground floor flat, this is a great way to keep the property warm. For a quick fix, seal the gaps between uncarpeted floor and skirting boards using a tube of caulk sealant from any DIY store, and add floorboard gap filler to reduce draughts. Just be sure not to block underfloor vents and grilles, as this could lead to problems due to moisture build up, such as the decay of floor joists.

This guide from Energy Saving Trust explains each of the above in a little more detail, including more on how easy they are to install and their benefits. You can also find out more in the UK Government’s buying green heating and insulation products consumer guide.  

 For any major work, find a trusted installer in your area. A good place to start is TrustMark – the Government endorsed scheme for work done around your home.  

Why take action?

Insulating our homes could benefit our finances as well as the environment:

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Reduce carbon emissions

A well-insulated home will help reduce energy use and, in turn, the consumption of fossil fuels and production of carbon emissions. Improving a home’s energy efficiency, through better insulation, for example, can reduce its carbon footprint by up to 900 kilograms of CO2e per year. 


Save money

Reducing the amount of energy needed to heat our homes saves money on utility bills. 


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Prevent mould growth

Insulation (and ventilation) plays a role in controlling condensation and preventing mould growth around the home. Remember to seek professional advice and pick the right materials for the type of home you live in. 

Home Insulation

Optimised Retrofit Programme

Jayne Martin from Pontardawe had external wall and roof insulation installed in her home as part of the Optimised Retrofit Programme. Find out how it helped her to feel more comfortable and save money.

Read Jayne's Story

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