External Wall Insulation Guide
External Wall Insulation Guide
External wall insulation is one of the most effective ways to improve your home’s thermal performance, reduce energy bills, and enhance exterior appearance. In this guide, you’ll learn how it works, its key benefits, and why it’s a smart upgrade for older or poorly insulated buildings.
External Wall Insulation
Improve your home’s energy efficiency and curb appeal with external wall insulation. Whether you’re retrofitting an older home or upgrading to meet modern standards, this guide covers everything you need to know.
What Is External Wall Insulation?
External wall insulation (EWI) involves adding a layer of insulating material to the outside of your home’s walls, then covering it with protective render or cladding. It improves energy efficiency by reducing heat loss through walls and can also enhance the appearance and weather resistance of your property.
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:
- Homes built before the 1920s with solid walls (which have no cavity to insulate).
- Properties with high heating costs or poor thermal performance.
- Buildings in cold or damp climates where wall insulation can help prevent condensation and mould.
Types of External Wall Insulation
The most common materials used for EWI include:
Expanded Polystyrene (EPS)
Lightweight and cost-effective.
Mineral Wool
Great for thermal and acoustic insulation and fire resistance.
Phenolic Foam
High-performance with thinner profiles.
How to Install External Wall Insulation
Installing EWI typically involves the following steps:
- Wall Preparation – Cleaning and repairing the wall surface.
- Fixing the Insulation – Boards are attached using adhesive and mechanical fixings.
- Applying the Basecoat – Reinforced with mesh for stability.
- Finishing Render or Cladding – Protects the insulation and enhances curb appeal.
