There’s plenty to consider when opting for a basement conversion. Here are our insider tips:
The two main types involve either renovating an existing basement or cellar or creating a new basement. Generally, it is more straightforward if you have an existing cellar or basement, and you may not need planning permission. Timewise, the project could take as little as one month if in good existing condition.
Creating a new basement will most likely need planning permission and is often the most expensive type of extension. You should allow 6-9 months from initial planning through to construction. The actual construction can last up to six months, depending on complexity.
Either way, you will need to comply with building regulations on the structure, fire resistance, access and escape means, insulation and ventilation, damp proofing, and water supplies.
The recommended ceiling height is 2.4 metres in order to create a comfortable living space.
Drainage is important. Investigate whether the conversion impacts your existing drainage, and if you need to divert this as part of the work.
Don’t forget a site survey to determine the implications of factors such as the local water table, and the geology of the underlying land.
You will also need to consider how you will access the basement from the original ground floor, and whether you want access onto your garden.
Top tip: Having your basement lead out onto a sunken garden space is a great way to introduce natural light!
Introducing as much light as possible is a key design consideration, and multiple lightwells are effective for this also. The exceptions would be if you were using the space for a cinema or wine cellar (we like your style!).
Finally, the Party Wall etc. Act 1996 (England and Wales only) often applies to basement conversions.
If you’re looking for a substantial increase in entertainment space, or want to preserve your garden space, a basement conversion is a very worthwhile option.