Extensions on existing properties are one of the most popular residential construction projects in the UK. Here, Charlie Ayers, MD of sustainable backing system brand SureCav, offers his tips on how to make your extension investment go further. 

‘Don’t move, improve’ has become an increasingly popular trend. As house prices fluctuate and COVID-19 reduces buying appetite, it’s likely more people will look to invest in their own homes in anticipation for sunnier times in the housing market.

Although not as expensive as some other structural renovation and improvement projects, extensions still represent a significant investment. Homeowners should consider a variety of factors to get the maximum value for their money. This ranges from thinking creatively about the layout of the build to achieving optimal thermal performance and energy efficiency through material choice.

The Case for Space

Most people, given the choice, would choose to live in a larger home with more space, particularly when they have growing families. There’s also a financial motivation. According to ONS, the average cost of a house sold is £2,395 per SqM.

Getting more space from an extension is often simpler than one might think, even within the parameters of a build. On a cosmetic level, it might be specifying wide windows, installing wall length mirrors or painting the space with light colours to create the illusion of a larger area.

When it comes to physically expanding, incremental gains can add up to significantly more internal room. Recessed skirting boards, built-in storage and pocket doors may seem modest, but in combination they make a noticeable difference. Further, new innovations in building materials can deliver a thinner wall, providing up to 7.5% extra floorspace without compromising on performance. Considering the worth of each SqM, this gain can accumulate to add significant value to the property.

The Efficient Secret

A standard, minimum level of energy efficiency is a legal requirement of any new build or structural improvement to an existing property. Not only does this rule help the environment through the reduction of carbon emissions, it also slashes homeowners’ gas and/or electricity bills.

However, older homes, built before the 2018 Domestic Minimum Energy Efficiency Standard (MEES), do not have the same performance levels as those built after the legislation came into effect. As such, adding an extension can be an excellent way to improve an old house’s thermal performance.

Getting the insulation right is key. Uninsulated, or badly insulated, walls can account for a third of heat loss from a home and, as such, should be a primary concern, particularly if using a cavity wall system.

Look at the make-up of the insulation and do some research into respective U-values of different products. These are calculations which show the heat transfer rate through a structure and performance will differ according to composition. It’s also important to consider location of the property, as some materials will be more appropriate than others depending on climate and weather conditions.

Poor insulation should be avoided at all costs, as it comes with the risk of damp formation or, worse, mould from warm air trapping more moisture. This will irrevocably damage the extension’s envelope, as well as causing potential respiratory and rheumatoid problems for occupants.

A Positive Solution

New, low-impact and sustainable building materials mean extensions can be made as energy efficient as possible. One quick and effective way to achieve this, particularly if you’re using a cavity wall system, is to see where positive substitutions can be made to drive down the carbon footprint.

One way of achieving this is to replace the standard backing block with a thinner option, made from recycled materials. This type of solution maintains an effective air gap, essential in cavity wall construction. They also seal the wall against the elements and outside moisture and keeps the insulation dry, preventing damp, rot and mould, protecting occupant health.

The added benefit of using such products is they also help reduce embodied carbon by replacing a thick layer of concrete from the build.

In today’s eco-aware society, it’s vital we pursue more sustainable construction practices. Reducing household operational emissions through a focus on energy efficiency is an excellent approach. Well-built cavity walls, particularly for extensions are an excellent way to achieve this.

We implore any selfbuilder looking to undertake an extension project to take the time to research what products are available to them to achieve optimal thermal performance and reduce environmental impact.

Big Benefits

Extensions can be a disruptive undertaking. However, the benefits are definitely worth it: more living space and a potential increase in property value. In the current climate it’s a financially savvy option. Still, such an investment needs to be well thought through and underpinned by quality in all things, from products to services.

Consulting accredited experts including architects and structural engineers is a good place to start. Carefully considering each step, especially the materials you specify, will deliver savings, sustainability and a more comfortable home environment.

Charlie Ayers, Managing Director, SureCav