Architect Sophie Bates reveals how to make your renovation and extension projects more sustainable

When undertaking a home renovation or extension, our first considerations are naturally all about our needs, the style, and budget. But, increasingly, sustainability is high on the agenda. There are many ways you can make your project kinder on the environment and these measures can also reduce running costs as well as making your home more appealing should you come to sell.

Insulate your home

Installing insulation will help to keep your home warm in the winter and cool in the summer, reducing your energy consumption and carbon emissions. The type of insulation you use and where you insulate will need to be thought through to ensure that good indoor air quality is maintained and the wider impact is carefully considered. For example, when installing new windows and insulation you need to ensure there is sufficient controlled ventilation otherwise air quality will be reduced and there is a risk of condensation, or, worse, mold forming. Often home improvements are done piecemeal rather than all in one go. Consider the wider picture long term and have a whole house retrofit plan to make sure that the works you do now consider future works e.g. if you are replacing windows, ensure the sill is long enough to extend beyond any future wall insulation to avoid altering the windows down the line. If you are looking to replace your flooring, consider insulating under the floor at the same time. There are different types of insulation suitable for different applications. Natural materials such a mineral wool and wood fibre will create better air quality internally as they are more ‘breathable.’ Breathable insulation can stop heat passing through walls while still allowing moisture to escape. It helps you to avoid problems with damp and condensation if installed properly. Natural materials are more environmentally friendly, using less CO2 to manufacture them. Often foam-based products e.g. PIR insulation, are readily available and sometimes cheaper but as they are plastic based they don’t let moisture move through them as easily and a careful ventilation design is needed.

Choose energy-efficient appliances and lighting

Look for appliances and lighting fixtures that have energy star ratings or other certifications indicating that they are energy efficient. LED light fittings are readily available and cost effective to run and can look fantastic integrated into the build.

Consider using renewable energy sources

This can include solar panels, home wind turbines, and ground or air source heat pumps. With energy bills rising, the payback time from installation is greatly reducing and there are some government grants available.

Use sustainable building materials

Look for materials that are recycled, locally sourced, or have a low environmental impact. Most building materials now have an Environmental Product Declaration (EPD) to allow you to easily compare materials.

Images: Main image top and 1,2: Sophie Bates Architects / 3,5,6: Sophie Bates Architects photo Karen Barrett / 4: Zoe Defert Architects, Sophie Bates Architects photo Simon Kennedy 

Opt for low-VOC (volatile organic compound) paints and finishes

These products emit fewer harmful chemicals into the air and can be better for your health and the environment.

Clever Landscaping

Careful siting of small trees can shade your extension in summer and then in winter, when the leaves have fallen, allow light into your home to help warm it through solar gain. Consider installing a green roof. The environmental and aesthetic benefits of a green roof can increase the value of your home by making it more energy efficient and attractive to look at. The structure of your roof needs to be strong enough so make sure this is designed in at an early stage when planning an extension. A green roof can keep your home warm in the winter and cool in the summer. This can reduce your energy use and energy bills. A green roof can also provide habitat for insects and birds and help improve air quality by releasing oxygen and absorbing pollutants. It can absorb and filter rainwater, too, reducing the amount of water entering the sewer system and help prevent flooding on a wider scale.

Conserve water

Install low-flow fittings for taps, showers and toilets so you will use less water each time. Consider using greywater systems: they collect used water from sinks and baths which can be reused for irrigation. Install a water butt: a simple, low-cost method to store rainwater from the rain falling on your roof into a storage unit to use to water your garden.

Connect to nature

Where you can, follow the principles of biophilic design, which incorporates elements of nature, such as plants, water and natural light into your home. In practice, this means using natural materials such as timber, brick and stone, including views of the sky and landscape to connect to the outside world and including patterns in design used in nature. This could be patterns in flooring, fabrics, shadows cast from the sun or in the architectural detailing. Studies have shown use of patterns allow us to make connections to nature and can reduce stress, improve creativity and improve our wellbeing.

Sophie Bates is a RIBA registered architect based in Teddington, and covering SW London, Surrey and the surrounding areas. Sign up for her newsletter for more sustainability tips: