External Wall Insulation: The Ultimate Guide
Published: 19/02/2024 18:00 by Spray Render Services
Example of wall insulation work on a recent project for a customer in Huddersfield.
With pressure on the wallets of households and businesses from around Britain continuing to grow, insulation is becoming an ever more popular property upgrade. Adding insulation to your property is one of the most effective ways of reducing heat loss during the winter months, reducing your heating bills. Furthermore, quality insulation will shield you from the scorching sun during the peak of summer. If you're wondering how external insulation can save you money on your energy bills, read on!
What is External Wall Insulation (EWI)?
External Wall Insulation installations consist of a layer of insulating material added (commonly Expanded Polystyrene or Mineral Wool) to the outside walls of your home or business to reduce heat loss during winter and heat gain during summer. The result is that you save on your energy bills as you are required to use less of your heating over winter and, if you have air conditioning, electricity over the summer months.
Which is better: Expanded Polystyrene (EPS) or Mineral Wool?
When opting for wall insulation to be added to your property, the choice of materials almost always includes these two. They're the most popular and, consequently, best-documented ones. Here is a summary of their differences:
Advantages of Expanded Polystyrene | Advantages of Mineral Wool |
|---|---|
|
|
Can insulation keep my house cool during summer?
Absolutely! Insulation assists with keeping the temperature inside your property stable all year round, including summer. Wall insulation can be a great alternative with no running costs (a study by Spanish researchers found that effective insulation of properties combined with night-time air flow could lower the indoor temperature by as much as 2 °C at night).
With each year being a record-breaking one in average outdoor temperature, heat waves are becoming an ever-growing health risk (a European study published in 2008 found that a 1 °C increase in temperature above 29.4 °C increased the mortality risk by 3% in the Mediterranean).
Heat waves in recent years have become more frequent and noticeable than ever before. Due to this, the demand for air conditioning units for houses has been steadily rising. While they are, without doubt, effective at reducing indoor temperatures, they do come with additional running costs that will make themselves very apparent during times of high energy bills.
Is External Wall Insulation right for my property?
If your property was constructed within the last 20 years, insulation was probably incorporated into the walls during the building process as per modern construction standards. However, it's important to note that the effectiveness of insulation can vary depending on factors such as the type and quality of insulation used, as well as any subsequent modifications made to the property. External Wall Insulation (EWI) can significantly enhance thermal efficiency, particularly in older buildings with solid walls where insulation might be lacking. Solid walls are typically found in buildings constructed before the 1920s when cavity wall construction became more common. These older structures often suffer from poor thermal performance due to their lack of insulation, making them prime candidates for EWI.
If you're uncertain about the insulation status of your property or whether EWI is suitable, don't hesitate to reach out to us for a professional inspection. Our team can assess your property's insulation levels, identify areas for improvement, and provide tailored recommendations to optimise energy efficiency and comfort in your home. Whether it's recommending additional insulation measures, suggesting upgrades to existing insulation, or determining the suitability of EWI, we're here to guide you toward the most effective solutions for your specific needs.
Do I need planning permission for External Wall Insulation?
Although not generally required, you may want to confirm with your local council if you need planning permission for an External Wall Insulation installation on your property. Furthermore, you may wish to consult your local planning authority if your property is listed or is in a conservation area. You may find that you're not allowed to go ahead with an installation that drastically changes the appearance of the building.
Unsure if your property is listed? You can check your postcode at the Historic England website.
How much does External Wall Insulation cost?
It is typically more expensive than Internal Wall Insulation. According to the Energy Saving Trust (ESA), an installation for a typical 3-bedroom semi-detached house is generally expected to cost around £12,000 compared to Internal Wall Insulation at £7,500.
You may want to consider that Internal Wall Insulation will require significant redecorating afterwards. Furthermore, the government has announced in 2022's Spring Budget Statement that a temporary 0% VAT rate will apply to Energy Saving Material (ESM), such as EWI, installations on residential properties until the end of March 2027.
How much can External Wall Insulation save me on my energy bills?
When installed on suitable properties, you can expect a reduction in heat loss of up to 45%. This translates, according to the ESA, to yearly savings between £180 for a mid-floor flat up to £660 per year for a detached house.
If you're interested in adding External Wall Insulation to your property, you can contact us today for additional information and a FREE quote.
You can learn more about our EWI services here.