Internal Wall Insulation Guide
Internal Wall Insulation
Internal wall insulation is a practical solution for improving the energy efficiency of homes with solid walls—without altering the exterior appearance. Whether you’re retrofitting an older property or looking to boost comfort and cut heating costs, this guide will walk you through everything you need to know, from how it works to which homes benefit most.
Internal Wall Insulation Guide
Looking to improve the energy efficiency of your home without altering its exterior? Internal wall insulation (IWI) is a smart, effective solution. It helps retain heat, cut energy costs, and make your living space more comfortable—all from the inside.
What Is Internal Wall Insulation?
Internal wall insulation involves installing insulating materials—typically rigid boards or stud frames filled with insulation—on the inside of exterior walls. It creates a thermal barrier that prevents heat from escaping through solid walls.
Benefits of Underfloor Insulation
Lower Energy Bills
Prevent heat loss and reduce heating costs.
Greater Comfort
Say goodbye to cold, drafty floors.
Noise Reduction
Insulation can help muffle sound between levels.
Sustainability
Use less energy and reduce your carbon footprint.
Moisture Protection
Prevent damp air from rising and protect floorboards.
Increased Property Value
Boost appeal with energy-efficient upgrades.
Which Homes Need It Most?
External wall insulation is especially beneficial for:
- Older homes with solid (non-cavity) walls.
- Listed buildings or homes in conservation areas where external changes are restricted.
- Flats or apartments where external access is limited or shared.
Types of Internal Wall Insulation
The most common internal wall insulation options include:
Insulated plasterboard
Quick and space-saving, it combines insulation with a finishing layer of plasterboard.
Stud wall system
Timber or metal studs filled with mineral wool or rigid foam, ideal for higher insulation performance.
Flexible insulation rolls
Often used in combination with battens and plasterboard.
How to Install Internal Wall Insulation
Installing internal wall insulation usually follows these steps:
- Wall Assessment – Check for damp or structural issues.
- Fix Insulation – Attach boards or build stud framework.
- Seal Gaps – Ensure airtightness to prevent heat escape.
- Finish Interior – Plaster and decorate the surface.
