Johanna Elvidge at Marshalls shares her advice for building sustainability into your home’s outdoor space to bring life-long benefits

Creating a sustainable home is now a top priority for self-builders, from locally sourced materials to energy efficiency measures. When it comes to your outdoor space, there’s plenty you can adapt to your design and add in once your initial build is complete. 

Begin by focusing on what you can source locally. Use a good mix of native and non-native plants to benefit pollinators, and consider flowering times to make sure there’s something in flower all year. Ensure plant success by choosing the right plants for the soil type and position in the space; your local garden centre can advise if you’re unsure. 

When it comes to planting, you can use reclaimed building materials instead of topsoil, diverting them from landfills and reducing the need for extra materials. The low nutrient levels in rubble are perfect for growing wildflowers; leaving some spaces to grow a little more ‘wild’ is great for biodiversity. 

Including habitats for wildlife within your garden design is another excellent way to support biodiversity. Creating piles of stones or logs within planting areas provides shelter for insects and invertebrates, and it’s another opportunity to reuse building waste on your site.

Buildings and pavements absorb and retain more heat than natural land, affecting health, energy use, biodiversity, water consumption and air quality. Trees and plants can help offset this as they increase the amount of shade and sun protection while also cooling the surrounding areas. 

Shaded surfaces under trees can be up to 11-25 °C cooler than unshaded surfaces, making them both useful and attractive. A building with a living wall or suitable climbing plant growing on it can impact both the outdoor and indoor temperatures, meaning less energy is required to cool inside in the summer or keep it warm in the winter.

When it comes to hard landscaping, you should consider permeability as well as selecting British-made or quarried materials. Whatever the material, it’s often harder for water to soak into the ground where it lands, leading to overwhelmed drains and flooding. You could consider permeable paving or grass paving flags to get around this. 

Permeable paving looks like regular block paving, but has a defined joint width and material, ensuring water can seep through the joints and reach the ground rather than run off into a drain. Grass paving is similar, but this type of solution forms more of a grid system, where the grass is encouraged to grow through the openings in the block. This has the additional benefits of increasing biodiversity and potentially lowering the temperature around your house on very hot days.

WATER REUSE

Reusing rainwater is an excellent way to reduce water consumption to benefit the environment – and your bills. It’s generally thought of as collecting the run-off from buildings via the guttering and storing it in tanks, but a simple water butt will do a great job if you’re short of space. For a stand-out sustainable design feature, you could create a rain box planter connected to a garden nature pond, with a tap and overflow onto a permeable surface.

Greywater is wastewater that comes from the home. Showers, baths and dishwashers are good sources; depending on use and ‘after-treatment,’ some are suitable for use elsewhere around the home. Water from washing machines and sinks is harder to reuse, and isn’t recommended for your garden. 

Greywater systems come in all shapes, sizes, and levels of complexity, but most have the standard features of storing the water, then a treatment process and a way to get the water to where it’s needed. As greywater contains organic matter, it does need some treatment if you store it for more than a few hours to minimise potential health risks.

The most straightforward way to implement a greywater system at home is to collect it from your shower or bath, and then allow it to cool for a few hours, allowing any debris to settle. You can then use this directly on non-edible plants. Using untreated greywater on fruit or crops is not recommended, and you should never mark it as safe for human consumption. Where looking to store and use greywater for more than a few hours, you should install a more robust system, ideally with treatment.

Johanna Elvidge is head of design at Marshalls