House extensions and structural alterations in London

Size, ground conditions and drains, the amount of structural work into the existing house, the size and type of glazing, the roof design, and the level of finish inside. A kitchen extension with a large sliding door, a rooflight and a new kitchen is a different project from a simple rear room.

We quote after the site visit with an itemised breakdown, so you can see the cost of the shell separately from the glazing, the kitchen and the finishes, and adjust before work starts.

A side-return extension fills the narrow strip beside the original back addition of a Victorian or Edwardian terrace, turning a narrow galley kitchen into a wide room without losing much garden. A rear extension adds depth instead. A wraparound combines both and gives the largest open-plan space, though it costs the most and usually needs a planning application rather than permitted development. We draw options for both so you can compare the space gained against the cost.

Yes. Removing a load-bearing wall means installing a steel beam, designed by our structural engineer, with padstones and sometimes new foundations below. The work needs building regulations approval and, where the wall is shared with a neighbour, a party wall notice. Done properly it is routine; the beam can be hidden within the ceiling depth so the two rooms read as one.

A single-storey rear or side-return extension usually takes ten to sixteen weeks on site once approvals are in place, from breaking ground to a finished kitchen. Add four to eight weeks beforehand for design and approvals if starting from scratch, and allow for glazing lead times of six to ten weeks, which we order as soon as the structure is confirmed.