Refurbishment and Restore Issue 14 2019 | Page 24

How much does a basement conversion cost? Ensoul As the total cost of moving to a new house in the £1m+ bracket becomes increasingly expensive, home owners are looking far more closely at the economics of improving their existing home. Therefore, as the trend for London basement conversions and extensions continues, the most popular question we get asked is “How much does a basement conversion cost?”. The issue that anyone has when they go online, or they talk to a basement contractor, is the price range. Estimated basement costs will vary from <£2,000 per sqr M to >£3,500 per Sqr M and the scope of what is included is often vague at best. 24 - www.refurbandrestore.co.uk To be fair, the reason for the wide cost range is due to several factors including: • Scope: Is this the cost for the “watertight shell and core” alone or does it include professional services and what about the fit-out costs? • Insurances and guarantees: the kind of insurances and warranties offered can have a material impact on costs • Geology and access: without a site survey, it’s impossible to ascertain ground conditions, water tables, drains, access routes, etc. All these are unknown risks that are priced in to high level estimates TERMINOLOGY Before we delve into the costs. The basement industry is full of jargon. Here are a few definitions that will help you navigate your way through the process: • Basement shell and core: This is the concrete box without any fit-out. • Professional services: This includes Architects, Interior Designers, Structural Engineers, Geotechnical Engineers, Arboriculturist to name a few. • BS8102:2009: The definitive standard to follow for making sure that your basement is watertight • Light-well: The escape hatch from your basement at the front or rear. It’s also a way of letting more light in and creating an extra space for possibly an urban garden.