Your Complete Loft Insulation Guide

The right insulation for your London property

The best material depends a lot on the age and construction of your home:

• Victorian & period homes — often have timber roofs that need to breathe. Breathable options like sheep wool, or carefully ventilated mineral wool, work best here.
• 1930s–1970s homes — usually straightforward open lofts. Knauf mineral wool to 270mm is almost always the most cost-effective choice.
• Modern homes (1980s onward) — typically already have some insulation; topping up to the full 270mm is quick and high-value.
• Loft conversions & rooms in the roof — limited depth, so slimline multifoil often makes the most sense.

Not sure which yours is? Our survey settles it in one visit, with honest advice and no pressure.

What good insulation actually does

Around a quarter of a home's heat can escape through an uninsulated roof, so getting the loft right is one of the highest-value improvements you can make.

• Lower energy bills — a properly insulated loft can cut a meaningful slice off your heating costs every year.
• A more comfortable home — warmer in winter and noticeably cooler upstairs in summer.
• A better EPC rating — useful if you plan to sell or let the property.
• A quieter house — insulation dampens sound as well as heat.
• A drier roof — with correct ventilation, insulation helps protect the roof structure.

What happens, step by step

1. Free survey — one of our own fitters visits, checks access, measures the loft and inspects any existing insulation and ventilation.
2. Fixed written quote — a clear price with no hidden extras, usually within 24 hours.
3. Installation day — we lay the insulation to the recommended depth, add any ventilation needed, and clear up fully. Most lofts are done in a single day.
4. Sign-off — we walk you through what was done and leave you the details of your guarantee.

Why your roof must breathe

Insulation and ventilation go together. Pack a loft with insulation but block the airflow, and moist air gets trapped — which leads to condensation, damp and eventually mould on the timbers.

Older roofs sometimes have a black bituminous felt membrane that does not let moisture escape, which is a common cause of loft damp. Where we find moisture problems, we fit lap vents (and improve airflow at the eaves) so the roof can breathe properly. We check ventilation on every survey, not just when there is a visible problem.

Work you can rely on

Every installation we carry out is backed by a guarantee of up to 10 years, covering the workmanship as well as the materials. Because we install with our own fully insured fitters — not subcontractors — we stand behind every job directly.

If anything is not right, you call us and we put it right. Simple as that.