However, although not as expensive as a house, extensions are still a significant investment. Homeowners need to consider various factors if they are to get maximum value. This can range from thinking imaginatively about layout for optimum living space to considering which materials to specify to improve energy efficiency, keeping bills down.
More space, better living
Given the choice, most people would choose to live in a larger home, with numerous and spacious rooms, particularly growing families. There’s also the financial element. According to the ONS, the average cost of a house sold is £2395 per square metre. Additionally, if more space means an extra bedroom, it can be rented out, providing an extra source of income.
How can homeowners get the most space out of an extension? Sometimes this can be achieved cosmetically. Wide windows, mirrors and light colours can make a room appear larger than it is. When it comes to physical expansions, incremental gains can add up to significantly more room. Recessed skirting boards, built-in storage and sliding doors may seem small changes, but combined they make a noticeable difference. Further, new innovations in building materials can make walls up to 100mm thinner. This provides 5 to 7.5% extra floor space. Considering a square metre adds £2395, this gain can quickly accumulate to add significant value.
Upgrade your energy efficiency
All new builds in the UK have to adhere to a minimum level of energy efficiency. Not only does this help the environment by reducing carbon emissions, it also significantly slashes occupants’ heating bills. However, older homes built before the 2018 ‘Domestic Minimum Energy Efficiency Standard’ (MEES) do not have the same performance levels as homes built after this legislation came into force. Adding an extension is an excellent opportunity to improve an old house’s overall thermal efficiency, bringing it up to speed with modern homes.
About a third of all heat lost within the home can be attributed to uninsulated or poorly insulated walls, so they should be your first port of call. Cavity walls are an excellent option for an efficient build and should be used for any new extension. The cavity can be filled with a layer of insulation, keeping heat trapped within the room. It’s also important to consider what the actual wall is made of. One thing to look for is a material’s U-value. This shows the rate of transfer of heat through a structure. The better insulated a wall, the lower the U-value.
Poor insulation carries the risk of damp forming, or worse, mould, as warm air traps more moisture. This can damage an extension’s envelope as well as cause respiratory issues for tenants – more important reasons to carefully choose building materials.
A positive solution
New innovations in building materials mean that backing blocks can be replaced by a non-porous, polypropylene sheet which maintains an effective air gap, an essential element in cavity wall construction. This seals the wall against wind-driven rain and other outside moisture, keeping the insulation within dry and preventing the formation of damp and mould. The sheet itself allows a thicker layer of insulation to be used in the cavity, delivering a lower U-value and improved energy efficiency.
An added bonus of using polypropylene sheets is they also help reduce embodied carbon, just like improved insulation. Using these sheets removes a layer of concrete within the wall.
Concrete is one of the most carbon-intensive materials in the construction sector. As such, designing it out is vital to help keep the industry’s carbon footprint as low as possible.
In today’s eco-aware society, it’s crucial we push for more sustainable construction practices. Reducing operational emissions of buildings through a focus on energy efficiency is an excellent approach to this issue.
Fortunately, balancing energy efficiency and occupant health needn’t be a zero-sum game. We implore any self-builder looking to undertake an extension project to take the time to research what products are available that will achieve both strong U-values and protect residents from damp.
While extensions can be a massive and disruptive undertaking, the benefits are worth it: more living space and a higher property value. In a sluggish market, it’s more financially savvy than moving to a brand-new home. Still, making such an investment needs to be well thought through.
Consulting experts such as architects and structural engineers is an excellent place to start. Carefully considering each aspect of the new build will bring savings, sustainability and a more pleasant living environment.