WE'RE OPEN: 7 DAYS A WEEK, 8am - 11pm
    Get a Valuation
    Register/⌂ Propertyfile
    Logo
    LogoLogo

    Open 7 days a week, 8am - 11pm

    Property Management

    PROPERTY MANAGEMENT / EMERGENCIES
    t: 0208 878 4277

    Barnes

    SALES
    e: sales@jabarnes.co.uk
    t: 020 8876 0100
    Contact Branch
    Properties for sale

    LETTINGS
    e: lettings@jabarnes.co.uk
    t: 020 8878 8688
    Contact Branch
    Properties to rent

    BARNES MARKET DATA

    East Sheen

    SALES
    e: sales@jasheen.co.uk
    t: 020 8876 6611
    Contact Branch
    Properties for sale

    LETTINGS
    e: lettings@jasheen.co.uk
    t: 020 8392 6161
    Contact Branch
    Properties to rent

    EAST SHEEN MARKET DATA

    Putney

    SALES
    e: sales@japutney.co.uk
    t: 020 8788 6611
    Contact Branch
    Properties for sale

    LETTINGS
    e: lettings@japutney.co.uk
    t: 020 8785 4400
    Contact Branch
    Properties to rent

    PUTNEY MARKET DATA

    Lifestyle

    Digging deep to add a basement

    almost 4 years ago

    Much has been made of this year’s ‘race for space’, with home movers buying and selling to gain an extra bedroom, a bigger living area or a much-coveted home office. When you couple this with news that a detached house was the most popular property type bought by new home purchasers during the pandemic, it’s no surprise there is a big squeeze on space.

    Many people buy a smaller property for its potential to extend but the traditional route is to go up – a two-storey extension or a loft conversion, for instance – but how about digging deep? It’s easy to assume that basement conversions are just for property high rollers, with A-list celebrities excavating to add a swimming pool, a home cinema or a gym complex, but can anyone add extra square footage by going underground? 

    With land at a premium, basements are gaining in popularity as an extension option. If you are considering this route, a quick look at other houses like yours may give you a clue as to whether you’ll enjoy success – if the properties already have basements, your plans will start on a positive note. 

    If you are not aware of a successful cellar conversion or basement excavation at neighbouring houses, you will need to work with a structural engineer and the local council on a feasibility study. They are likely to raise the following points:

    • The Party Wall Act: neighbours will need to be notified about any planned work as part of this Act, as it may involve underpinning their party walls and inserting beams into shared brickwork.
    • Permissions: your local planning officer and building control department will decide what’s possible and what will need planning permission.
    • Evaluation: every aspect of your home and land, from soil type and the water table to access and service pipework will need appraising as part of the planning stage. If you don’t understand what heave and hydrostatic pressure is – and how they can affect basement plans – consult with the professionals.

    Don’t forget that creating a basement isn’t a run-of-the-mill building project. Going underground requires a team of experts, including structural engineers, surveyors, architects, excavators and waterproofing professionals. This basement guide, created by SWJ Consulting, is a good read for those who’d like more detail about what adding a basement involves.

    The need for specialist skills brings us to the cost of creating or converting a basement, and this will vary according to what you have already. If you’re converting an existing cellar, costs can range between £900 to £1,400 per square metre. If your basement is brand new and requires excavating, expect to pay in excess of £1,500 and £2,000 per square metre.

    It’s wise to contact everyone who needs to be on board for an estimate before getting too carried away. Ask about their availability too – the best trades can be booked up for months and demand may also mean their prices rise (as will a shortage in building materials).

    So will a basement end up paying for itself? The answer is: possibly. For the shrewd property owners out there, basements may present a way of creating an additional income stream. Xcavate Robotics is a company that works with homeowners to establish whether they can squeeze additional underground properties onto their land, with the build taking place under their garden. 

    Its subterranean construction system is capable of adding a lower ground floor below an existing structure, and it can even carve out an entire one-bedroom apartment beneath a lawn – perfect as a property that can be rented out, or as an annexe for multi-generational families.

    Even if you’re not looking to become a landlord, adding a basement can add as much as 20% to your home’s value, reports the HomeOwners Alliance. Already have a cellar? Even converting somewhere dark, dingy and demoted to a dumping ground will increase your property’s worth.

    Ask us for advice and examples if you’re looking to buy a property with basement potential. If the idea sounds like too much hassle and you’d prefer the work to have already been completed, we can find you a home with more space than you have now.

    Share this article

    More Articles

    Home improvements that don’t require planning permission

    Home improvements that don’t require planning permission

    Published 16 days ago

    Earlier this year, it became apparent that home buyers aren’t that fussed about finding the ‘perfect’ property. A Rightmove survey of 34,000 home movers found 73% of those leaving rented accommodation viewed fixer uppers as a more affordable route to property ownership. Additionally, 73% of existing homeowners wanted to buy a property that needed work in order to create their dream home.

    Read More
    Pattern drenching: when more is more

    Pattern drenching: when more is more

    Published about 1 month ago

    Avid readers may remember our blog on colour drenching – the interior design trend that sees every surface in one room – walls, ceiling, woodwork and radiators – painted in the same colour.

    Read More
    Every seller should try biophilic decluttering

    Every seller should try biophilic decluttering

    Published 2 months ago

    Described by House Beautiful as ‘the secret to a calm and clutter-free home’, biophilic decluttering is a trend we can really get behind. It merges two interior aspects that are hugely important when selling a home – presenting a property that’s clear and streamlined, and dressing a home so it is visually appealing.

    Read More

    Sign up for our newsletter

    Subscribe to receive the latest property market information to your inbox, full of market knowledge and tips for your home.

    You may unsubscribe at any time. See our Privacy Policy.

    Back to Home

    GUIDES 

    Selling a property
    Letting a property
    Buying a property
    Renting a property

    LETTINGS BRANCHES 

    Barnes
    East Sheen
    Putney

    SALES BRANCHES 

    Barnes
    East Sheen
    Putney Hill
    Lower Putney

    ARLA
    Guild
    NAEA
    OnTheMarket
    RightMove
    ThePropertyOmbudsman
    © 2025 James Anderson
    Privacy policy|Terms & conditions|Cookie policy|CMP Certificate
    Powered by