Exterior walls, together with the roof, form the envelope of any building, protecting everyone and everything inside.

They also cover the largest surface area, making them a prime area for preventing heat loss. The main place where heat is lost is by escaping through poorly insulated walls.

With ROCKWOOL external wall insulation, living spaces can be made warm, energy efficient and compliant with modern building standards – as well as gaining additional benefits in terms of acoustics, indoor comfort and fire safety.

Discover the importance of insulation for exterior walls, and the positive impacts it can bring.

Why do we need exterior wall insulation?

Outside walls are where heat loss or heat penetration most commonly occurs in the majority of buildings.

Exterior wall insulation can significantly moderate this – improving the building’s energy efficiency, as well as cutting CO2 emissions and reducing fuel or cooling costs.

Exterior walls come in different shapes and forms. These range from cavity walls to rendered systems and façade cladding, for domestic, commercial and industrial buildings. Each type of external wall has its own advantages and disadvantages. They appeal to the building owner in one way or another, by assuring good energy performance that meets local requirements.

Key benefits:

  • Less heat loss
  • Lower energy bills
  • Protected building structure
  • Lower temperature fluctuations
  • Fewer damp issues
ROCKWOOL boasts excellent thermal performance both in winter and summer. Stone wool slabs can add significant mass to the building envelope, ensuring summer comfort by keeping the heat outside. The fibres in the tightly butted slabs knit together, significantly reducing heat loss that’s caused by gaps between slabs.

Erica Bazzini

Global Product Manager, ROCKWOOL Group
Matt Risinger Trailblazer images

Installing Comfortboard 80 on a typical wood framed and sheathed wall with a non-flanged window

Watch the demonstration video.

Premium partnership program for builders

ROCKWOOL R‑Class is our premium partnership program for builders who demand more.

This is a community for those who take pride in their craft. They use high-performance materials and installation techniques, to ensure their homes are comfortable, beautiful, efficient and built to last.

When a builder joins the R‑Class, you’ll receive support and training by our team of residential building pros, samples, potential rebate savings and more. ROCKWOOL high-performance stone wool is in a class of its own — and so are the builders who make up the R‑Class.

Residential Builder installing ROCKWOOL


Will external wall insulation stop condensation?
How long does external wall insulation last?
What is ETICS?

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