Does External Insulation for Walls Work?

Have you noticed your energy bills steadily creeping up? Rising costs and environmental concerns make it crucial to find ways to make your home more energy-efficient.

One solution that has gained popularity is external wall insulation (EWI). But does it work? Let’s explore this question in depth.

What is External Wall Insulation?

External wall insulation or solid wall insulation is a method of adding an insulating layer to the exterior of a building’s walls. This layer acts as a blanket that prevents heat from escaping through the walls. 

The insulation materials commonly used in EWI systems include rigid insulation boards made of materials like mineral wool, expanded polystyrene (EPS), or polyisocyanurate (PIR).

The installation process involves affixing these insulation boards to the existing walls, followed by a protective render or cladding layer. This outer layer not only safeguards the insulation but also gives the building a fresh, updated appearance.

The Benefits of External Wall Insulation

External wall insulation offers several advantages beyond just improving a home’s thermal efficiency:

  1. Improved thermal efficiency and energy savings: By reducing heat loss through the walls, EWI can significantly lower heating costs and energy consumption.
  1. Enhanced weatherproofing and protection against moisture: The added insulation layer and protective render create a weatherproof barrier, protecting the walls from moisture and other environmental factors.
  1. Increased property value: Homeowners who invest in external wall insulation often see a significant boost in their property’s market value, as energy-efficient homes are highly desirable and command higher prices.
  1. Aesthetic improvements and modernized exterior appearance: EWI can transform the look of a building, giving it a sleek and contemporary finish.

Does External Wall Insulation Work? The Evidence

External wall insulation has proven to make a substantial difference in reducing heat loss and improving thermal efficiency. 

Numerous studies and real-world examples have demonstrated the effectiveness of external wall insulation in reducing heat loss and improving energy efficiency.

 According to the Energy Saving Trust’s report, solid wall insulation like EWI can decrease heating costs by up to 25% annually.

Case Studies: Successful EWI Installations

Many homeowners and building managers have reported significant energy savings and improved comfort levels after installing external wall insulation. Here are a few examples:

  • The homeowner in London, UK, reported a remarkable 50% drop in their heating bills after installing a high-quality EWI system, showcasing the substantial difference it can make in reducing energy consumption and costs.


External wall insulation has proven to be an effective solution for improving a home’s energy efficiency and reducing heating costs. It offers numerous benefits with its ability to minimize heat loss, enhance weatherproofing, and modernize a building’s appearance.

If you’re considering external wall insulation for your home or building, consult us and explore the various EWI options available. You can enjoy the benefits of improved energy efficiency by taking the necessary steps. 

Leave a Comment