Basements

Terraced house basement

We provide structural design for terraced house basement conversions, including new basement excavations, underpinning, retaining walls and permanent structural alterations. Terraced properties require careful assessment of the shared party walls, neighbouring foundations and restricted construction access. We design the permanent underpinning arrangement, reinforced-concrete walls and slabs, steel beams and stair openings to safely transfer the existing house loads. Our design also considers soil conditions, groundwater, nearby drainage, trees and adjoining structures.

End-terrace and semi-detached house basement

We provide structural engineering for end-terrace and semi-detached house basements, where the building normally has a shared party wall on one side and an exposed external flank wall on the other. We assess the existing foundations and design the necessary underpinning, retaining walls, ground slab and structural connections. The exposed side may require additional retaining-wall design and lateral support to resist soil and groundwater pressures. We also consider lightwells, stair openings, drainage routes, soil capacity and the effect of excavation on neighbouring structures.

Detached house basement

We provide structural design for detached house basements, including full-footprint excavations, basement extensions and new-build basement structures. Detached properties can involve larger excavation areas, deeper retaining walls and more complex load paths from the building above. We design reinforced-concrete walls and slabs, underpinning, columns, transfer beams and foundation details to safely support the existing structure. Groundwater, soil capacity, trees, drainage and nearby foundations are also considered.