5m deep basement within busy city centre

basement for a swimming pool under a listed facade


The construction of a new basement poses a number of engineering challenges and our experience is that the structural engineer needs to be involved from the start of the project. The key issues are identified at an early stage allowing budgets and programmes to be developed with greater certainty, and a zone for the basement structure is allowed for in the planning of the proposed layout.

There are generally a number of solutions for the basement structure and it is important to allow sufficient time in the programme to develop the optimum solution. Criteria will include the space taken up by the structure, waterproofing, constraints imposed by the site such as soil conditions, trees or adjacent buildings, and buildability issues like the sequence of construction and temporary works.

It is becoming more common for local authorities to ask for a structural engineering report to accompany a planning application that includes a new basement, especially if there are potential implications for listed buildings. We have provided structural reports, either as part of the design team or as a specialist consultant. Our reports are written in a non-technical language and accompanied by clear drawings. They are underpinned (sorry for the pun!) by a combination of our experience of basement designs, an understanding of buildability issues and our expertise of works to historic buildings.

basement for a private house around protected trees

basement for a listed building in Central London

1 South Eaton Place, Sloane Square

The existing mews building behind a large mid-19th century house within a conservation area was dismantled between the party walls and rebuilt to similar heights with a new basement over the entire plan area of the mews.

The two party walls were underpinned with reinforced concrete retaining walls cast in front of the underpins, while contiguous reinforced concrete piles support the ground to the front and rear elevations.

Mowbray Road, Kilburn

A new basement was constructed towards the rear of the house and supports a one storey high rear extension. Part of the basement was under the existing house which needed to be underpinned and the existing rear wall had to be temporarily supported.

basement during construction

rear extension with basement under

Hampden Road, Hornsey

Conversion of the basement and ground floor of a 19th century, end of terrace shop into two flats. The existing cellar was lowered and underpinned to provide adequate headroom and a new external lightwell within reinforced concrete retaining walls was added to provide access and additional rooms. Concrete internal walls act as buttresses at regular spacings to provide supports to the retaining walls.

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