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How to build an energy efficient house extension

Going green not only saves the planet, it can also help you save on bills, and increase your home's value.

3 min read

Once the domain of hippies and guys named Dreadlock Dan, becoming energy efficient is now mainstream - especially for homeowners. Not only does it help you save the planet, but it also helps save some pennies when it comes to household bills.

If you’re looking to go green, there are three things to remember:

  • Lighting
  • Heating
  • Insulation

Remember this trio and you’re on your way to a creating an eco-friendly space. Here’s how to apply these principles to your extension...

Building your extension

Energy efficiency can be enforced right at the get go, through the use of cavity concrete blocks over regular bricks. This means that you can use external wall insulation (EWI) to ensure that your property is enveloped in the best possible insulation - even though this process is slightly more expensive, in the long run it will cut your bills by 40%.

The use of polyisocyanurate (PIR) is a fancy name for a blend of materials forming a rigid foam product, a great way to insulate your extension from the ground up as it's a floor insulation that improves heat retention.

Double glazed windows over regular panes is perhaps one of the simplest insulation methods out there. Although, as with concrete blocks, this option is slightly more costly than your average window, we definitely advise that you splash out on this initial cost to save yourself roughly £80 per year in the long term. You can also check out the U-values of different panes of glass, a helpful way to measure the rate of heat loss through your window. The lower the U-value, the better the thermal performance of the glass.

Heating doesn’t always need to be break the bank

There are countless practical, financial, and environmental benefits to using underfloor heating as the primary heat source in your home, a concept that is not commonly acknowledged as a stand-alone alternative to central heating. Not only does it save 15% to 50% on heating bills, but it avoids the need for clunky wall-hung radiators, spreads heat more evenly, and operates at a lower temperature.

If you do stick with radiators, avoid positioning large items such as sofas and sideboards near radiators, as these objects are likely to unnecessarily absorb a lot of heat.

Also, all heating methods can be amplified through effective draught proofing, the process of blocking unwanted gaps that let in cold air. You can either hire a professional to do this, or simply do it yourself for a lower cost.

Bright ideas to save on lighting costs

LED lights have been growing in popularity, mostly because they use 90% less electricity than regular bulbs. While LED lamps are more expensive than CFL lamps, it’s important to remember they have a much longer lifespan. Not to mention, are more durable and eco-friendly.

The most obvious preventer of high lighting costs is taking advantage of natural light, either by installing skylights or large glass doors. This not only keeps costs down, but, in our opinion, creates a more attractive space.

skylight infographic final-01 copy

Looking to make green your build? Book a free consultation call with our team to have our experts show you how to transform your home, and your carbon footprint.

Design your own extension

With Resi Ready, you do the designs yourself on our whizz bang tech configurator. It’s the simplest way to get a spiffy new home extension.

Let's have a play

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