With UK energy prices still fluctuating and the pressure to meet net zero goals mounting, homeowners are searching for smarter, more sustainable ways to heat their homes. One proven solution is External Wall Insulation (EWI)—a system that can slash heating bills by up to 40%, all while improving comfort, aesthetics, and energy performance.
In this article, we explore how EWI works, the real savings it can deliver, and why now is the perfect time to consider insulating your property with one of Benx’s certified systems.
What Is External Wall Insulation (EWI) and How Does It Work?
EWI involves fixing insulation boards to the external walls of a property and finishing with a protective render or cladding system. It is especially effective for homes with solid walls—typically properties built before the 1920s, which lack cavity insulation and lose more heat as a result.
By wrapping the property in a thermal “jacket,” EWI helps to:
- Prevent heat loss through external walls
- Reduce the amount of energy needed to keep the home warm
- Improve airtightness and thermal comfort year-round
At Benx, we offer fully certified EWI systems, designed to meet modern performance, fire safety, and aesthetic requirements.
The Numbers: How Much Can You Save?
The Energy Saving Trust estimates that insulating solid walls with EWI can reduce heating bills by up to 40%. Actual savings will vary based on your home’s size, current insulation levels, and energy usage—but here’s an example:
A typical 3-bedroom semi-detached home could save £630–£820 a year on heating bills with EWI, based on average energy use in 2025.
Considering the lifetime of the system (typically 25+ years), many homeowners see a return on investment within 8–12 years—even faster if they qualify for grant funding.
More Than Just Savings: The Full Benefits of EWI
While lower bills are a major incentive, the advantages of EWI go beyond financial gain:
- Comfort: More consistent indoor temperatures, fewer cold spots and draughts
- Sustainability: Reduced carbon emissions and energy usage
- Aesthetics: EWI can transform a tired-looking façade, increasing kerb appeal
- Value: Improved EPC ratings can raise property value and attractiveness to buyers
- Protection: Weatherproofs your property, reducing damp and water ingress risk
What Funding Support Is Available in 2025?
Although the Green Homes Grant has ended, funding is still available through schemes such as:
- ECO4 and ECO+ – for eligible homeowners and landlords
- LA Flex – locally managed funding routes based on wider eligibility
- Social housing funding – available to housing associations for large-scale upgrades
- 0% VAT – on insulation installations, extended by the UK government until 2027
Benx can help you navigate funding options or work with your installer to find the best route.
Why Choose Benx?
Benx is a leading supplier of façade and insulation systems in the UK, trusted by contractors, developers, housing associations, and installers alike.
- Fully certified systems – including our new through-wall insulation solutions
- Innovative materials – such as CladWool, our mineral wool insulation range
- End-to-end support – from technical design through to site delivery
- National network – with branches in Stoke, Basildon, Cardiff and Wishaw
Whether you’re upgrading one home or managing a portfolio, we’re here to help.
Ready to Save? Let’s Talk
If you’re ready to reduce your energy bills and future-proof your home, our team is here to help. Visit our Refurbishment or Contact Us pages to get started, or speak to one of our experts about the best EWI solution for your project.