Basement in a London Home - Cost on the pocket

Updated: Dec 3, 2018

A basement in your home is no doubt a bonus. An extra habitable space instantly ups the value of your home in case you are planning to float it in the real estate market. However, building a basement is not that simple. Due to its structural and construction complexity, the expense of carving it out and giving it a finished look sometimes acts rude to the pockets.

The below pointers will help you understand in giving shape to a potential basement and factors affecting the overall cost:

· If you already have a cellar, you have almost halved the cost of finishing a basement Vis a Vis digging out an entirely new one.

· The basement built under the garden is not much functional as the one directly under your house. However, some opt for this, as it is a way cheaper.

· The closer the water table is, the more challenging it is to avoid future damping; hence the added cost of prefixing it.

· For Basement with an external access, shed an extra £6000 - £8000.

· Another key factor adding to the expenses is the effort put in diverting sewers and drains.

· Add to this, the land value, excavation cost, and type of waterproofing system.

Depending on the size of a property and the amount of excavations, the cost of a basement addition in –

- An average three bedroom London home is 4000£/m² - 5000£/ m².

- A typical Victorian terraced house is £75,000 – £140, 000.

Winsham Grove, London, Basement Extension. WWW.INTEGRATE.HOMES

Generic Breakdown of Costing

§ Fully fitted structural conversion - 300£/ft² + VAT

§ Structural shell and waterproofing – 150 - 200£/ft²

§ Conversion of the existing cellar - 750 – 1400£/ m²

§ New builds - 300£ - 450£/m²

§ Job cost - £200, 000

§ New basement underneath a garden - 1500-2000£/m²

§ Lowering a floor level and underpinning an existing cellar - 1500- 2000£/m²

§ New basement and underpinning - 2000£ - 3000£/m²

§ External access - 5000-7500£

§ Engineer’s fees - 1000£ - 1500£

§ Planning application - 165£

§ Building regulation application - 750£ + value of the work

§ Party wall agreement - 700£/ neighbour

§ VAT - 20% by the registered contractors

§ Electrics, plumbing, staircase, plasterboard walls, flooring - 900£/m²+VAT

With this information at hand and your budget in mind, you can pick the quality you desire and opt for a design that best suits your requirement.

Mehran Gharleghi


If you are thinking of a home renovation or building a brand-new home, contact us to benefit from our FREE phone consultation.

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