What affects the cost of loft insulation

1. The size of the loft

Insulation is bought and laid by the square metre, so the floor area of the loft is the starting point. A bungalow has a bigger loft than a two-storey house with the same number of rooms.

2. What’s there already

A loft with sound, dry insulation that just needs topping up is the simplest job. A loft with none needs both layers. A loft where the old insulation is damp, dirty or soiled by pests needs it removed and disposed of first, which adds labour and waste costs.

3. The material

Mineral wool rolls are usually the lowest-cost option. Sheep’s wool, recycled polyester, rigid boards and blown insulation each cost more or less depending on the product and the loft. See insulation types compared.

4. Access and working conditions

A tall, empty loft with a ladder is quick to work in. A small hatch, low headroom, trussed rafters, lots of pipes and cables, or a loft full of belongings all take longer.

5. Extras

• Raised boarding for storage
• A loft ladder or insulated hatch
• Ventilation such as eaves vents
• Lagging pipes and tanks
• Downlight covers
• Clearance of old belongings or debris

6. Funding

Government and energy-supplier schemes come and go, and who qualifies depends on things like income, benefits and the property’s energy rating. Check GOV.UK for what is available now; we can tell you if any scheme applies to your home.

Getting a price you can compare

Ask anyone who quotes to list exactly what is included: material and depth, whether old insulation is removed, hatch, pipes, ventilation and waste. Two quotes for “loft insulation” can describe quite different jobs.