House
extensions
in St James's, SW1

The 2002 audit records that infilling at the rear has taken place in many locations in St James's, and says the internal courtyards and rear gardens that remain are important. An extension here is usually a question about a small yard or courtyard behind a house where earlier infill may already have taken much of the plot, and the first test is how much open space would be left.

At the front, the audit describes building lines set on the pavement edge or behind shallow lightwells with railings, and notes that many good quality original railings survive. We keep front lightwells and railings out of an extension brief; if the lower floor needs more light, we look at the rear first.

Brick, the audit says, is principally found in the secondary routes, in the smaller mews-type buildings and at the rear. A rear addition is therefore normally detailed in brick matched to the house's own bond and colour rather than in the Portland stone of the main frontages.

Most of the original 17th and 18th century mews survive hidden between St James's Street and Green Park, and Blue Ball Yard still opens onto a granite setted mews. Work behind these houses often shares access with neighbours, so the party wall line and any shared yard are checked before a design is fixed.

Westminster does not permit demolition, excavation or piling on Saturdays without special permission, and we plan any foundation work around that.

The St James's Conservation Area was designated on 27 March 1969 and extended in 1974 and 1987, and the audit describes buildings of every age that have seen few alterations affecting its character. An extension is judged against that record.

We draw the whole existing rear elevation, later additions included, before proposing a new one, so that the planning drawings show clearly what is original and what is not, and we photograph it from neighbouring yards where access allows.

Most of the original 17th- and 18th-century small mews survive hidden between St James's Street and Green Park, the audit records. A rear addition nearby is designed to leave those mews, and the light they receive, as they are.

Not in St James's, but a related project: Belsize Park Gardens, NW3, a whole-house project in Belsize Park, NW3, whose scope included the loft, the basement and an extension. We point to it because the work is comparable; the project itself is outside St James's.

Where the work touches a shared wall or digs near a neighbour's foundations, we prepare the party wall notices before the programme is fixed and record the condition of the neighbouring side. Glazing on a rear addition is chosen with the windows that look onto the yard in mind. Where a yard serves more than one building, we confirm who owns it and who has rights over it before anything is drawn.

Sources: Westminster City Council: St James's conservation area audit (SPG, adopted 27 November 2002); Westminster City Council: noise problems we can investigate.