Westminster / Camden
We design side-return extensions for St John's Wood terraces and semi-detached houses. The complete address selects Westminster or Camden; the measured boundary, structure, drainage, neighbouring openings and mapped records determine the footprint, consent route and whether Party Wall procedures apply.
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The short answer
It may be possible where the measured building and side strip support an infill. Confirm Westminster or Camden, the mapped heritage and Article 4 position, planning history, boundaries, adjoining openings, structure and drainage before fixing the design; do not assume planning or Party Wall outcomes.
Planning at a glance
St John's Wood
| Local planning authority | Westminster City Council or London Borough of Camden — confirm the exact address |
|---|---|
| Postcode districts | NW6 / NW8 |
| Likely approval route | Householder planning application or permitted development, depending on conservation status, listing and property type — confirmed for the exact address before drawings begin |
| Statutory determination time | 8 weeks for most householder applications (13 weeks for major applications) |
| Local planning note | St John’s Wood and NW8 are place and postcode descriptions, not local-authority or conservation-area boundaries. Confirm the complete address and application site before using council material. For a Westminster site, use the City Plan 2019–2040 (2026), current policies map and the mapped conservation-area, Article 4, listing, tree and planning-history records. For a Camden site, the Camden Local Plan 2017 remains current; the Proposed Submission Draft is still at examination and must not be described as adopted. Use Camden’s mapped conservation-area appraisal, Article 4, listing, tree and planning-history records for the exact site. Westminster and Camden maintain separate St John’s Wood conservation records, so do not infer one designation or adoption date from the neighbourhood or postcode. Westminster’s city-wide basement Article 4 direction came into force on 31 July 2016; Camden’s borough-wide basement direction was adopted on 1 June 2017. Other Article 4 controls are address- and operation-specific. Westminster’s basement policy and Code of Construction Practice and Camden’s Policy A5 and Basement Impact Assessment process are separate. Planning permission, listed-building consent, title or landlord consent, Building Regulations or BSR approval, Party Wall procedures and tree controls remain separate. |
| Where most projects start | Planning Route Review — £395 inc. VAT, credited in full against your package if you proceed. Find my package → |
Where the surveyed house has a rear wing and side strip, an infill may widen the rear room or combine with a measured rear projection. We establish the legal boundary, adjoining building, existing openings, structure and below-ground services before deciding how much of that strip can form part of the design.
Rooflights, rear glazing and the roof profile are tested against the room depth, orientation, adjoining openings and overheating risk. The daylight strategy follows the measured site instead of assuming that a continuous rooflight, a large rear opening or any standard proportion is right for every side return.
Party Wall procedures apply only if the designed foundations, wall work or other operations are notifiable under the Act. Establish the boundary, wall ownership, adjoining foundations and structural method before deciding who must receive notice or whether surveyors and an award become necessary. Planning permission does not settle that separate procedure.
Survey soil and rainwater pipes, gullies, chambers and sewer records within the proposed footprint. If the work affects a public sewer, check the relevant undertaker's current requirements; any build-over or build-near agreement, diversion or access detail follows the actual asset and proposal rather than the side-return label.
The complete address selects Westminster or Camden, and the legal building type, operation, planning history, mapped designation and live directions decide whether permitted development or an application route applies. Where an application is needed, the responsible authority assesses the extension's depth, height, glazing, neighbour amenity and effect on the applicable rear and garden context.
Detail the junctions between the new roof, existing wing and any boundary wall from the surveyed construction. Roof build-up, upstands, flashing and rainwater disposal must be coordinated with structure and glazing. Those drawings reduce avoidable risk but do not guarantee performance, approval or a particular room outcome.
Local analysis
Survey the boundary, wall ownership and adjoining foundations before placing the new structure. The Party Wall etc. Act applies only where the actual work meets a statutory notification test. If it does, provide the relevant structural and boundary information for the separate procedure without assuming neighbour consent, appointment of surveyors, an award or a fixed programme.
Record any rainwater gully, soil stack, chamber and below-ground run within the proposed footprint, and establish ownership from current records. Where a public sewer is affected, check the relevant undertaker's current requirements. Access, diversion, build-over or build-near details are then designed for the actual asset and coordinated with the foundations.
Test rooflights and rear glazing against the measured room, orientation, adjoining openings and garden context. If the complete site lies in a mapped Westminster or Camden conservation area, assess the roof form, glazing and materials against that council's applicable appraisal. The evidence can explain the proposal but cannot establish permission in advance.
Thinking about a project in St John's Wood?
Send the address and a short description. We will confirm the likely approval route and the drawings your project needs.
Local planning
Confirm the complete address and application site before selecting Westminster or Camden policy, planning history and mapped conservation records. For a qualifying dwellinghouse, test the side-return proposal against every applicable Part 1 limit, condition, history restriction and live Article 4 direction; conservation status alone does not remove every right.
If an application is required, the responsible authority assesses the proposal against its current policy and the evidence for the exact site. Rear elevation, garden context, depth, height, roof form, glazing, neighbouring outlook and daylight may be relevant, but no proportion or design formula establishes approval.
St John's Wood and NW8 do not establish an authority, conservation designation or Article 4 position. Confirm the complete address and application site, then use only the responsible council's current policies, maps, directions and planning history; do not route the project from a street example or nearby permission.
Westminster and Camden maintain separate St John's Wood conservation maps and appraisals, and not every address or NW8 property is designated. If the complete site is mapped within one, assess the side return's scale, roof, glazing and material junctions against that council's applicable record.
Use the responsible council's current map and property record for any local heritage status. A neighbourhood description does not establish designation, significance or the treatment of a particular rear elevation.
Search the exact address on the National Heritage List and responsible council records. If the building is listed, listed-building consent is required where cutting openings or joining new work to the rear affects its special architectural or historic interest; planning permission remains a separate decision.
For the wider local-authority picture — policies, timescales and application routes — see planning in Westminster.
Services
Extensions & Renovations
Planning & Consents
Technical & Building Regulations
Leasehold & Licence to Alter
Nearby
Send us the complete St John's Wood address, application site and photos of the rear wing and side strip. We will identify Westminster or Camden, check mapped constraints, boundary and drainage evidence, and set out the design and consent questions without promising an outcome.
