How to make your new home extension sustainable

Environmental sustainability is in the news almost every day now, and not just because of the COP26 global climate conference.

Latest reports from the scientific experts say we all need to do more and urgently to limit the rise in global warming to avoid an unstoppable chain reaction and climate disaster in a matter of a few decades.


Save money

You don’t have to be Greta Thunberg to want to do what you can to ensure we all have a future on this planet.

Anyone planning a home extension or conversion can and should look into the ways it can be sustainable, partly because by reducing its carbon footprint at all stages of its life you will also ensure you save money on your heating bills.

Here are some of the things you should think about and discuss which your designer.



The material you build your extension or conversion with will, obviously, be heavily influenced by what the existing house is made from.

While it will need to complement what you already have, and comply with any planning restrictions in your area or relating to your property, you should consider what else might make your finished home more sustainable as a whole.

Wood sourced from sustainably-managed forests is a popular and environmentally friendly choice, partly also because of its ability to be blended into a variety of home styles.


Reclaimed materials

Reclaiming existing building materials is a great way to plan sustainability into your project.

If you prefer or are limited to bricks, reclaimed bricks of the right colour and age will allow you to do your bit for the ‘circular economy’ – keeping materials in use - while blending into your existing home’s style.

Your design team can advise on reclaiming and reusing timber floorboards and beams, glass panels and windows, whole doorsets as well as steel, slates and granite. All of these can be sourced by you or your builder from specialists and local demolition companies as well as using any salvaged materials from your project..



Windows account for 50% or more of energy lost in your home, so installing high-performance units in your extension or conversion will retain heat, save money and help the planet. 

Ask your designer about options including triple-glazing, special coatings, nonconductive framing materials and airtight construction. 

The frames need to be well-insulated with a good U-value - the rate of heat flow through it (lower is better). Triple-glazed windows with a vacuum between the panes can further decrease heat loss.



Ensuring you have a continuous layer of insulation across the walls, floor and roof will allow you to keep draughts out and minimise spend on heating. 

‘Green’ options include:

  • Sheep’s wool
  • Loose-fill cellulose made from 85% recycled newspapers and 15% fire resistant material - which has the most amount of recycled content of any insulation product
  • Recycled jeans - denim is an excellent insulator, thought more expensive than traditional options

If your extension or conversion will have a hot water supply, don’t forget to insulate the pipework as this will ensure your water stays hot.


Heating Options

Underfloor heating is not only trendy, but its’ also an energy-efficient choice for heating your extension or conversion because the heat is in all areas and rises, rather than the pockets of warm air radiators create. It operates at a lower temperature too, which means it can save your money.

Wood-burning stoves have been a popular choice for some time and, apart from looking nice, they’re typically cheaper to run than an electric fire and good on sustainability if the fuel wood has good eco-credentials.



Skylights not only enable natural light to flood into your home, reducing your electricity bills, but they’re a source of passive solar heating. 

Don’t forget to include blinds - to control the temperature and stop heat building up in Summer and escaping in Winter. When triple-glazed, a skylight can achieve good thermal values. 

Another natural lighting option that could save on your power bill is bi-fold or sliding doors. See our blog here for considerations when choosing between them.

Where letting lots of natural light in isn’t an option, opt for LED lighting – which can cut your lighting costs by up to 90%. Less power used also means more sustainable!



Everything inside your extension or conversion which uses power will also contribute to its sustainability, so look carefully at the energy consumption ratings for any new fridges, dishwashers, cookers, tumble dryers or water heaters you plan to install as part of the project.



Once your extension is built and ready to decorate, you can still add to its sustainability score by choosing paints which have been manufactured in more eco-friendly ways and don’t pollute the air you and your family are breathing indoors.


As you see, there are a lot of ways to make your home extension or home conversion as sustainable as possible. Contact us to arrange a chat about the full range of things to think about.


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All Design is a dedicated, friendly team of architectural designers who work alongside external associates and consultants to help people across Scotland find property solutions through carefully-considered designs which respond to their needs, the site, budget and planning policy.

We have more than 30 years of experience in the industry and thrive on using a creative yet practical approach to design to improve space for people.

Our values are: People; Honesty, Delivery; Creativity and Friendly.

Contact us for a FREE quotation.

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