The authorities are reluctant to grant planning permission for visible upward extensions and the footprint of many properties means that there is significant potential for substantial basement extensions. Indeed, building extensions below the ground harks back to the Victorian era when many people had their wine or coal cellars constructed underground. If you own a house in London, you also own some of the ground below your premises, making this a logical option for an extension.

What are the advantages of basements in London? – It can be far cheaper to extend than to move, particularly with the recent changes in stamp duty at the higher end of the market. Given central London property prices, it is well worth considering working with what you’ve got and extending the building.

You do not need to have an existing cellar in order to create extra accommodation. Today’s construction technology, including elements such as waterproofing, has advanced to a point whereby an underground conversion is now viable in situations which would, hitherto, have proved to be impossible or prohibitively expensive.

You can of course generate income from the new living space as it can be rented out, using it as an entirely separate flat for visitors, tourists, students or corporates looking for relocation and accommodation solutions for key staff.

Indeed, a basement extension can be used for a wide variety of purposes. It can become an extra suite of bedrooms, living rooms, nanny accommodation or an entertainment or leisure complex. Some so-called hyper basements even include a substantial swimming pool and a gymnasium.

The limited availability of natural light is easily addressed thanks to modern, intelligent LED lighting solutions and contemporary construction techniques ensure that there is no adverse impact in areas such as groundwater or the structural integrity of the building and its neighbouring structures.

Building downwards also gives you the freedom of choosing the number of floors required, in sharp contrast with any visible upwards extension. Your new basement complex will not affect any view from the neighbours and will not overlook others, minimising the likelihood of justifiable planning objections.

Effective management – There are of course issues associated with the construction of a significant basement extension. Neighbours will be unlikely to welcome the accompanying noise and intrusion associated with the build but an experienced contractor will be able to minimise what is, after all, a short term issue.

Despite the associated cost, having a basement extension is almost invariably a sound financial decision for owners of central London properties – and indeed properties in any location in which space and land is at a premium. The precedent has long since been set with numerous examples to be found in high end locations such as the Royal Borough of Kensington and Chelsea. If you select the right professionals, the entire project can be designed to minimise the intrusion associated with the construction process and the outcome should more than justify the time and the investment.