Waldemar Avenue, London

Client: FCM Holdings

Location: Fulham, London

Project: Remodelling and extension to two flats to create luxury, duplex apartments

Project Value: circa £1.5 million

Contractor: Space Basements

Status: Completed 2019


The site was two apartments in a five-storey Edwardian mansion block in a prime location in Fulham, west London. The apartments had the benefit of a large garden and our client had also obtained the rights to develop into the storage basement.


We were tasked with maximising the potential of, not only the existing apartments, but also the space beneath them.


The project faced many challenges. Firstly, we had to secure a planning permission in a conservation area and to a building of townscape merit, for a project that was initially considered wishful-thinking by the local authority planners. In retrospect, that was the easy part.

The technical stage of work required careful structural and architectural design to ensure the safety and well-being of the incumbent residents in the mansion block.


Party Wall Awards were put in place and structural testing was carried out. After many design iterations, with the accompanying planning amendments, the site works started.

With extensive propping, tunnel excavations, and movement detectors, the basement was lowered with no movement of the host building; a remarkable feat.

We created both apartments as duplexes, one having a side garden overlooking an open green space, and the other having a private rear garden accessed through its kitchen and a new light-well. Further lightwells were used to allow daylight and ventilation to the lower ground floor rooms.

The client/contractor at FCM carried out the build with no issues and the finished apartments, maximising this valuable piece of real estate, are a credit to the team’s perseverance.

Barrowgate Road, Chiswick

Client: Private

Location: Chiswick, London

Project: House remodelling and extensions, including basement.

Project Value: £700k

Contractor: Space Basements

Status: Complete

The existing house, on one of the more celebrated avenues in Chiswick, was a large Edwardian family home with many period features and high ceilings. There was an existing storage basement with low ceilings. The house suffered from significant damp and water ingress.

To extend the home to the rear, into a new, larger basement, and into the roof. The damp and water ingress issues were to be resolved, and there were other areas of improvement. We were asked to make substantial alterations to an unviable planning permission and optimise the construction of the building on a technically challenging site.

Finding and resolving the water ingress problem was the greatest challenge. Deepening and extension the basement had to be carefully planned with the family staying in the houses and avoiding movement of the building as a whole.

We worked with damp specialists and water-tested many areas before agreeing on a resolution to the water ingress issues. The basement construction was carefully planned with the family, to avoid clashes with their daily lives, and the exam period for the children.

The result was a raised terrace-room, which opened out to the garden, above a new basement, games and entertaining space, along with a small gym and wine store. The basement could be accessed from the terrace-room or from deeper within the home.

There was significant archaeological interest in the site and a 7-month excavation was ordered, unearthing and cataloguing hundreds of artefacts. The archaeological sensitivity of the site required careful planning of the ground structure to avoid impacting on the finds.

Leave a Reply