What is loft insulation and how does it work?

Loft insulation is a thermal barrier installed in your roof space to slow down the transfer of heat between your home and the outside. It is usually made from mineral wool, fiberglass, or rigid insulation boards. By trapping air in millions of tiny pockets, it reduces heat loss in winter and heat gain in summer, keeping your rooms more comfortable and lowering your energy bills.

How much money can I save by installing loft insulation?

The savings from loft insulation depend on your property size, current insulation level and energy usage, but many UK homes can save up to hundreds of pounds a year on heating bills by upgrading to the recommended depth of insulation. Homes with little or no existing loft insulation tend to see the fastest payback, often within just a few years.

How thick should my loft insulation be?

Current UK guidance typically recommends around 270 mm of mineral wool insulation in the loft to achieve good energy performance. If you already have some insulation in place but it is below this depth or has been compressed over time, topping it up to the recommended thickness can significantly improve efficiency and comfort.

Is loft insulation suitable for my type of property?

Most properties with an accessible loft space can benefit from loft insulation, including detached, semi-detached and terraced houses, as well as many bungalows. If you have a flat roof, a very shallow loft, or a loft that has been converted to living space, different insulation methods may be needed. A professional survey from Energy Plus can confirm the most suitable option for your property.

Can I get loft insulation for free or with government funding?

Depending on your circumstances and the latest government schemes, you may be able to access funding or heavily subsidised loft insulation. Support is often available for households on certain benefits, with low incomes, or living in hard-to-heat homes. Energy Plus can check your eligibility and help you apply for any grants or funding you may qualify for.

How long does loft insulation installation take?

For a typical house with easy loft access, professional loft insulation can usually be installed in just a few hours, often within a single day. Larger properties, restricted access, or additional work such as boarding or ventilation upgrades may extend the timescale, but disruption to the household is usually minimal.

Is loft insulation messy or disruptive to install?

A trained installer will aim to keep disruption to a minimum. Some dust and noise are unavoidable while materials are being brought through the house and laid in the loft, but protective sheeting and careful working practices help keep your home clean. At the end of the job, the installers will remove waste and leave the loft tidy.

Can I still use my loft for storage after insulation is installed?

You can still use your loft for storage, but heavy items should not be placed directly on top of the insulation, as this compresses it and reduces its performance. Many homeowners choose to add raised loft boarding over the insulation to create a safe storage platform while maintaining the full insulation depth underneath. Energy Plus can advise on suitable storage solutions during your survey.

How do I arrange a survey or quote for loft insulation?

You can arrange a no-obligation survey by contacting Energy Plus through our website or by phone. A qualified assessor will visit your property, check your existing insulation, identify heat-loss issues and talk you through the best options, including any available funding. After the survey, you will receive a clear quotation so you can make an informed decision.

Loft Insulation Guide for UK Homes

Q: Will loft insulation cause damp or condensation problems?

When installed correctly with adequate ventilation, loft insulation should not cause damp or condensation issues. In fact, it can help create a more consistent internal temperature, which reduces the risk of condensation. A professional survey will check existing ventilation and recommend any improvements needed before installation so that moisture can escape safely.

Discover how loft insulation can cut heat loss, lower your energy bills and make your home warmer and more comfortable all year round.

Why loft insulation matters

In a typical uninsulated UK home, up to 25% of heat can escape through the roof. Loft insulation creates a thermal barrier that keeps warmth in during winter and helps keep your home cooler in summer. It is one of the most cost-effective home energy upgrades you can make.

Whether you live in a terraced house, semi-detached, detached property or bungalow, correctly installed loft insulation can reduce your heating demand, cut carbon emissions and improve comfort in every room.

Lower heating bills: Use less energy to heat your home, especially during colder months.
Improved comfort: Fewer draughts, more consistent temperatures and less noise from outside.
Smaller carbon footprint: Reducing energy use lowers your household CO₂ emissions.
Long-term value: Quality insulation can last for decades and enhance your home’s EPC rating.

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How loft insulation works

Warm air naturally rises. Without insulation, that heat escapes through your ceilings and roof, forcing your boiler or electric heating system to work harder. Loft insulation slows this heat flow by trapping air in thick layers of insulating material laid between and across the joists or rafters.

For most UK homes, the recommended depth of mineral wool loft insulation is around 270 mm. Many older properties still have much less than this, meaning they are losing more heat than necessary.

Types of loft insulation for UK homes

The best type of loft insulation for your property depends on your roof structure, how you use the loft space and your budget. Below are the most common options used in UK homes.

Blanket (roll) insulation

Usually made from mineral wool, fibreglass or sheep’s wool, blanket insulation comes in rolls that are laid between and over the joists. It is the most widely used and cost-effective solution for standard lofts.

Ideal for easy-access lofts with regular joist spacing.
Can be a DIY project, though professional installation ensures the correct depth and coverage.
Works well for lofts used only for storage (with raised boarding if required).

Blown-in (loose-fill) insulation

Blown-in insulation uses loose mineral wool, cellulose or similar materials that are blown into the loft using specialist equipment. This is useful where access is restricted or joists are irregular.

Good for hard-to-reach areas and awkward spaces.
Fast installation with minimal disturbance.
Must be installed by a trained professional.

Insulation boards

Rigid boards (such as PIR or phenolic foam) can be fitted between rafters or over joists. They are often used where you want to create a warm loft or convert the loft into a living space.

High insulating performance in a relatively thin layer.
Suitable for sloping ceilings and loft conversions.
Must be carefully fitted to avoid gaps and thermal bridges.

Natural and specialist materials

Where sustainability or moisture control is a concern, you might consider natural or specialist insulation materials such as sheep’s wool, wood fibre or multi-foil products.

Can offer better moisture regulation and acoustic benefits.
Popular in heritage and timber-framed properties.
Usually higher upfront cost but long-lasting performance.

How much can loft insulation save?

The exact saving depends on your property size, fuel type and current insulation levels. However, for many UK households with little or no loft insulation, upgrading to the recommended depth can:

Cut annual heating bills by hundreds of pounds compared with an uninsulated roof.
Reduce heat loss through the roof by up to a quarter.
Pay back the installation cost in a relatively short period through bill savings.

Insulation upgrades are also strongly reflected in your home’s Energy Performance Certificate (EPC), which is increasingly important for resale value and mortgage eligibility.

Tip: If your loft insulation is under 150 mm thick, topping it up to around 270 mm can still deliver noticeable savings and improved comfort.

Signs your loft needs better insulation

Bedrooms feel cold or draughty, especially upstairs.
Heating turns on frequently to maintain temperature.
Snow melts quickly on your roof compared with neighbours.
You can easily see joists above existing insulation.
Energy bills have increased and you have not changed habits.

If any of these sound familiar, a professional loft insulation survey could help identify cost-effective improvements.

Loft insulation and your whole-home energy plan

Loft insulation works best as part of a wider home energy efficiency strategy. By combining it with other measures, you can maximise comfort and savings.

Cavity & solid wall insulation

Walls are another major source of heat loss. Cavity wall insulation for suitable properties and internal or external insulation for solid walls can dramatically reduce your heating demand.

Floor insulation & draught proofing

Insulating suspended timber floors and sealing gaps around skirting boards, loft hatches, chimneys and windows helps keep warm air in and cold air out.

Heating systems & controls

Once your home keeps heat more effectively, modern boilers, heat pumps, smart thermostats and radiator controls can operate more efficiently, further reducing your bills.

Professional loft insulation installation

While some homeowners choose to install simple blanket insulation themselves, using an approved installer helps ensure your loft remains safe, ventilated and compliant with current Building Regulations.

A typical professional loft insulation installation will include:

Survey and assessment – Checking existing insulation, loft access, ventilation, wiring and pipework.
Preparation – Protecting electrical cables, water tanks and pipework, and dealing with any damp or condensation issues.
Installation – Laying or blowing insulation to the correct depth and coverage, avoiding gaps and cold bridges.
Finishing touches – Insulating and draught-proofing the loft hatch, and advising on safe storage options.

Installers should follow guidance from recognised bodies such as the British Standards Institution (BSI) and industry best practice to ensure long-term performance.

Using your loft after insulation

If you use your loft for storage or plan a future conversion, it is important to insulate in a way that supports these plans.

Storage only: You may need raised loft boarding above the insulation level to avoid compressing the material.
Future loft conversion: You might opt for rafter insulation or insulation boards to create a warm loft space.
Access and safety: Good lighting, safe walkways and an insulated hatch make the loft easier and safer to use.

A qualified installer can design a solution that balances energy efficiency, storage and long-term flexibility.

Grants and funding for loft insulation in the UK

Depending on your circumstances and where you live in the UK, you may be able to access help with the cost of loft insulation. Support changes over time, but options can include:

Government-backed schemes such as the Energy Company Obligation (ECO) and other local programmes.
Local authority grants targeting households in fuel poverty or low-income areas.
Installer finance options that spread the cost over manageable monthly payments.

Eligibility varies and is often based on income, existing insulation levels, benefits received and property type. A quick assessment can confirm which schemes you might qualify for.

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Loft insulation FAQs

How long does loft insulation last?

Quality loft insulation can last 40 years or more when installed correctly and kept dry. It is largely maintenance-free, though it is sensible to check occasionally for damage, damp or disturbance.

Will loft insulation cause damp or condensation?

Properly installed loft insulation should not cause damp. Good ventilation is essential, and any existing moisture issues should be addressed before work starts. A professional installer will ensure vents are clear and the loft can breathe.

Can I still use my loft for storage?

Yes, but insulation must not be compressed by heavy boards or stored items. Raised loft boarding systems can create a safe storage platform above the insulation while preserving its effectiveness.

Is DIY loft insulation a good idea?

Confident DIYers can install basic blanket insulation in a simple, dry loft. However, for complex roofs, limited access, electrical or damp issues, or blown-in insulation, professional installation is strongly recommended.

Do I need to insulate the loft hatch?

Yes. An uninsulated and poorly sealed hatch can undo much of the benefit of loft insulation. Adding insulation to the hatch and fitting draught seals helps maintain an unbroken thermal barrier.

Is loft insulation suitable for all roof types?

Most UK homes can benefit, though the method differs for flat roofs, trussed roofs, low headroom spaces and loft conversions. A survey will identify the best approach for your particular roof structure.

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Updated on 8 Dec 2025