Should You Build a Basement?

Our neighbours on the continent have recognised the advantages of home basements for many years, but here in the UK we’ve been a bit slow on the uptake. In places like Germany and Switzerland, most houses have one, so the benefits in terms of space and cost versus value are well understood.

The scarcity and high cost of plots, decreasing size of new build footprints and planning constraints limiting height are squeezing available space for new houses.

As self builders are often the first in the home building sector to implement new ideas, it’s no surprise that many appreciate the value of the space under their building site.

Can I add a basement to my home?

No longer dark and dingy zones, basements can be used as hobby rooms, home cinemas, gyms and swimming pools, even self-contained apartments.

By creating an additional floor downstairs you get extra accommodation without changing the footprint of the property. This can be useful even if you just use the basement for building services, laundry or storage, as it frees up space elsewhere.

Key considerations

When planning a basement project, it’s hugely important that it’s completely waterproof. Having gone through the extensive process of designing and constructing a new house, the last thing anyone wants is signs of damp and leakage, which can leave lasting damage on your property’s building fabric and structural integrity.

It is vital that the basement materials used keep out moisture. So you’ll want a basement system that includes waterproofing methods that will allow you to be eligible to receive an insurance-backed guarantee.

Having an external area leading out from the basement, even if simply for a staircase, offers the opportunity for natural light to be filtered into the storey

Top quality insulation materials are used to create a warm and inviting space, also helping to minimise heat loss. This will help to prevent the formation of condensation and the musty smell associated with older basements.

Incorporate as much natural light as possible – for instance, having glazed doors, leading out to a lowered outdoor courtyard, are ideal. Light wells will also serve this purpose if windows need to be fully underground.

In most cases, adding a basement level costs much less than you might first assume – our fixed price projects typically account for approximately 10% of the total house build project cost.

That said, construction fees can be higher in cases with problematic ground conditions or on complex basements designs. However, many of our clients with sloping plots are able to use a basement to exploit what may be seen as a disadvantage to create additional usable space.