Loft Insulation Cardiff & South Wales – Save on Energy Bills
Professional loft insulation from The Green Deal Cardiff. Warmer rooms, lower bills and support with grants and funding.
Book a Free Loft Insulation Survey in Cardiff
Find out if your loft is properly insulated, how much you could save on your heating bills and what funding may be available.
Call us: 08008 101060 | 07960 799681
Why Loft Insulation Matters in Cardiff & South Wales
If you live in Cardiff or anywhere in South Wales, good loft insulation is one of the simplest and most cost-effective upgrades you can make. Around a quarter of a typical home’s heat is lost through an uninsulated roof – which means you’re literally heating the sky.
Whether you’re in a Victorian terrace in Roath, a semi in Whitchurch or a bungalow in Barry, proper loft insulation helps you:
- Cut your heating bills
- Make your home warmer and more comfortable
- Reduce condensation and mould risk
- Lower your carbon emissions
- Improve your EPC rating and property value
We install modern loft insulation across Cardiff and South Wales, tailored to your property and any existing insulation.
How Loft Insulation Cuts Your Energy Bills
Lower Heating Bills
Good loft insulation slows heat escaping through your roof. Your boiler or heating system doesn’t have to work as hard, so you:
- Use less gas or electricity
- Can turn the thermostat down a little and feel the same comfort
- Enjoy savings that continue for the lifetime of the insulation
More Comfortable Rooms All Year Round
If your bedrooms are upstairs, poor loft insulation is usually why they feel cold in winter and boiling hot in summer. Properly installed loft insulation helps keep bedrooms and upstairs landings at a more stable, comfortable temperature all year round.
Reduced Condensation & Mould Risk
In Cardiff and across South Wales, damp and condensation are common problems. Warm, moist air rises and can hit cold roof surfaces, leading to condensation in the loft, damp timbers and mould growth.
Insulation, installed correctly with suitable ventilation, helps keep surfaces warmer and can reduce the risk of condensation forming, protecting both your home and your health.
Better for the Environment
Using less energy means lower CO₂ emissions and a more sustainable home. Loft insulation is often one of the first improvements recommended on an EPC, and can help improve your rating when it comes to selling or renting.
Adds Value to Your Property
Buyers and renters are increasingly focused on running costs, EPC ratings and damp issues. A well-insulated loft is a simple selling point that indicates the home has been looked after and will be cheaper to run.
What’s Involved in a Loft Insulation Install?
Every home is different, but a typical loft insulation job in Cardiff or South Wales includes:
Survey & assessment – checking your existing insulation depth, access, ventilation and any issues such as damp or damaged timbers.
Insulation upgrade or replacement – topping up existing insulation to modern recommended levels, or removing old, damaged insulation and replacing it.
Attention to detail around cold spots – such as loft hatches, pipes and cables.
Advice on storage – if you use your loft for storage, raised boarding can be fitted so you don’t crush the insulation.
Areas We Cover in Cardiff & South Wales
The Green Deal Cardiff installs loft insulation across Cardiff and South Wales, including:
Cardiff
Penarth
Barry
Newport
Caerphilly
Pontypridd
Bridgend
Vale of Glamorgan
Surrounding areas
Funding & Grants for Loft Insulation
Depending on your circumstances and the latest government schemes, you may be able to access funding or support for insulation improvements. The Green Deal Cardiff can help you understand what you might be eligible for and how loft insulation fits alongside other measures in your home.
To learn more, visit our page on ECO4 and insulation funding in Wales or contact us for free advice.
Beware of Bats!
If Bats are present in the loft, you cannot have your loft insulated- it’s illegal. They are a protected species and must not be disturbed. However, the loft can be insulated during their “away period”.
Loft Insulation FAQs – Cardiff & South Wales
1. How much heat am I really losing through my roof?
In a typical uninsulated or poorly insulated home, around 25% of heat loss is through the roof. That’s why loft insulation is usually one of the first improvements recommended on an EPC (Energy Performance Certificate).
📞 0800 8 10 10 60 or 07960 799681
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2. How thick should my loft insulation be?
Modern guidance generally recommends around 270 mm (10–11 inches) of mineral wool insulation. Many older homes in Cardiff and South Wales only have 50–100 mm, which is far below this.
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3. Will loft insulation make my house too hot in summer?
No. Loft insulation helps in summer as well as winter. It slows heat entering from the roof on hot days, so upstairs rooms tend to feel cooler and less stuffy.
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4. How long does loft insulation last?
Most mineral wool loft insulation can last 30–40 years or more if it stays dry and undisturbed. It’s not something you have to redo every few years.
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5. Can loft insulation help with damp or condensation?
Loft insulation can reduce the risk of condensation by keeping surfaces warmer, but it must be installed correctly with suitable ventilation. As part of our survey, we check for existing damp issues and make sure any insulation works with, not against, your loft ventilation.
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6. Will I still be able to use my loft for storage?
Yes, but heavy storage directly on top of the insulation can compress it and reduce its effectiveness. The usual solution is raised loft boarding over the insulation so you can safely store boxes without squashing it.
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7. How long does it take to install loft insulation?
Most standard-size lofts in Cardiff and South Wales can be insulated within a few hours, depending on access, existing insulation and any preparation needed.
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8. Is loft insulation messy or disruptive?
We work from the loft space, so disruption inside the home is minimal. There will be some movement through the house to access the loft, but we use dust sheets and tidy up afterwards. Most homeowners can stay in the property as normal while the work is carried out.
The insulation is taken into the loft in polybags. The insulation is removed from the bags, and the empty bags are then removed – there is no mess whatsoever.
📞 0800 8 10 10 60 or 07960 799681
📩 Enquiry Form
9. Can I get help with the cost of loft insulation?
Depending on your circumstances and the current government schemes, you may be able to access funding or support for loft insulation. The Green Deal Cardiff can point you in the right direction and help you understand what you might be eligible for.
There are 2 current grant schemes in Cardiff and the surrounding areas. One is ECO4, and the other is The Great British Insulation Scheme (GBIS). ECO4 is a multi-measure scheme, whilst GBIS is a single-measure scheme.
Under GBIS, loft insulation is only free as a secondary measure with cavity wall insulation, and that has only been available since May 2025. Before that, loft insulation was only installed in very rare cases, and this was because the funding for loft insulation was extremely poor.
Under ECO4, loft insulation can be installed free of charge, but it would have to be a part of a multi-measure project.
📞 0800 8 10 10 60 or 07960 799681
📩 Enquiry Form
10. Will loft insulation affect my roof or electrics?
Properly installed insulation does not damage your roof or electrics. Cables are checked and, where necessary, placed above the insulation or routed safely. Ventilation is also considered so the roof structure can continue to “breathe”.
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11. Will loft insulation really make a noticeable difference?
Most households notice warmer bedrooms and landings in winter, less need to “blast” the heating, and a reduction in heating bills over time. You may also notice fewer cold drafts and a more even temperature between rooms.
It will also help to reduce or eradicate condensation if your home suffers from condensation.
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12. How do I know if my loft is already insulated properly?
If you can safely access your loft, a quick look will tell you a lot.
Measure the depth of the insulation. If it is more than 100mm (4 inches), it won’t get a free grant? Check for gaps or bare patches, and see if it looks damp, compacted or damaged.
If you’re unsure, The Green Deal Cardiff can carry out a professional loft survey and give you clear, honest advice.
📞 0800 8 10 10 60 or 07960 799681
📩 Enquiry Form
Ready to Improve Your Loft Insulation?
Get in touch with The Green Deal Cardiff for a free, no-obligation loft insulation survey anywhere in Cardiff or South Wales.
📞 0800 8 10 10 60 or 07960 799681
📩 Enquiry Form
