Improve home insulation

Home insulation affects heat loss, damp risk, ventilation, comfort and bills. The right measure depends on wall type, loft access, cavity condition, roof structure, suspended floors, existing ventilation and whether windows or heating will also change.

Good Insulation contractors do not treat insulation as a simple blanket. They check moisture, cold bridges, ventilation and existing defects so the home gets warmer without trapping damp.

Wall and loft insulation can mean loft top-up, cavity wall insulation, external wall insulation, internal wall insulation, floor insulation, draught proofing or a whole-house retrofit. Each has different disruption and risk.

Quotes should explain the building fabric, material, thickness, ventilation plan, enabling works, making good and warranties. The cheapest cavity fill is not right for every wall.

Loft insulation commonly costs around GBP 900 to GBP 2,000, cavity wall insulation around GBP 1,000 to GBP 3,000, and external wall insulation can range from GBP 10,000 to GBP 25,000 or more. Access, scaffold and making good drive the spread.

A proper comparison includes survey, ventilation, material, thickness, scaffold, render, trims, guarantees and any damp repairs. Grants may change affordability, but quality matters because poor insulation can cause mould.

The process runs from survey and fabric assessment to quote, grant check, preparation, installation, ventilation checks, making good and handover. Loft work can be quick; external wall insulation usually takes weeks.

Good installers photograph hidden work and explain how ventilation has been maintained. If the home already has condensation, solve airflow and moisture sources before adding insulation.

Mineral wool, blown fibre, EPS, wood fibre, PIR, phenolic board and internal insulation boards all behave differently with moisture, fire, acoustic performance and carbon footprint.

The best material depends on the wall and risk, not only headline U-value. Vapour control and ventilation details are as important as thickness.

Before work starts, clear loft access, wall areas, gardens and scaffold zones. External work depends on weather and drying times.

Sequence insulation with windows, roof and heating upgrades. Doing windows after external insulation can damage new reveals; fitting a heat pump before insulation may oversize the system.

Common mistakes are insulating over damp, blocking ventilation, ignoring thermal bridges and choosing a system without local exposure in mind. Poor retrofit work can look fine at handover and fail months later.

Use funding, checklists and the customer guide to compare survey quality. Ask the installer how they prevent condensation, mould and cold bridges at edges.