Architects, Engineers, Surveyors & Builders Under One Roof.
Surveyor-led refurbishment advice via Hampstead Chartered Surveyors →One Studio. One Contract. One Team.
We deliver St John's Wood side return extensions with extension designers, engineers and builders under one fixed-price contract - planning, structural design, party wall coordination, procurement, directly managed site teams, Building Control and final handover through one accountable team.
Every side return extension project in St John's Wood is designed to respect the St John’s Wood Conservation Area and the character of stucco Italianate villas, Regency terraces, large mansion blocks. Our in-house RIBA architects handle Westminster planning applications, our chartered structural engineers specify any load-bearing work, and our directly-employed trades deliver the build under one fixed-price contract. We coordinate Building Control, Party Wall awards where needed, and all certifications through to handover.
St John's Wood's conservation area status means extensions must be sensitively designed. Westminster expects extensions to use matching or complementary materials and to respect the scale and character of the original building. We navigate these requirements daily.
Exclusive residential area within Westminster. St John's Wood conservation area features wide, tree-lined streets with substantial detached and semi-detached houses. Home to Lord's Cricket Ground and Abbey Road Studios. Side-return extensions are particularly popular in St John's Wood's terraced streets, transforming narrow kitchen spaces into full-width open-plan living areas connected to the garden.
Victorian and Edwardian terraces were built with a narrow alley beside the rear closet wing — dead space that collects bins and shade. A side return infill claims that strip and folds it into the kitchen, turning a dark galley into a full-width room without losing any garden. A small footprint holds a dense engineering problem: building against a neighbour’s wall, removing your own flank wall, and re-routing the drainage that almost always runs down that alley.
Five stages, with the boundary and structural questions answered before anything is demolished.
Expect 12–20 weeks on site from groundworks to practical completion. Read the full side return extension guide for roof options, glazing comparisons and terrace case detail.
Because the work happens on or beside the boundary, the Party Wall etc. Act 1996 shapes the timetable of nearly every side return: building at the line of junction, cutting into the party wall for steel bearings and excavating near a neighbour’s footings each trigger their own notice, and if an adjoining owner dissents, a surveyor’s award must be in place before that element starts. Building Regulations approval is needed whatever the planning route. Our planning guide library covers the consent picture borough by borough.
Side returns punish loose coordination: the steel, the boundary and the neighbour relationship all have to be managed by people who talk to each other daily. Here the design comes from our in-house RIBA Chartered Architects, the structural calculations are produced in-house, and RICS surveying support for party wall and condition matters comes through our sister company, Hampstead Chartered Surveyors. You get one fixed-price JCT contract backed by £10M public liability cover, a 12-month defects period and a 10-year structural warranty. Enquire before 2pm on a weekday and we respond the same day.
House extensions in St John's Wood typically cost £3,000–£5,000/sqm. A single-storey rear extension runs approximately £69,000–£115,000, while a double-storey extension costs £115,000–£207,000. Our fixed-price contracts include foundations, structural steelwork, full build and interior fit-out.
Visit our studio or invite us to survey your home. We’ll assess scope, discuss design possibilities and provide an honest budget framework — completely free.
We survey your property, discuss your vision and provide a clear budget framework.