Westminster / Camden
We design loft and roof conversions for St John's Wood houses and flats, including dormers, mansards and rooflights. The complete address selects Westminster or Camden, and the measured roof, legal building type, mapped heritage record, title or lease, structure, stair and fire strategy determine the route.
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The short answer
The route depends on the complete address, legal building type, roof and proposed work. Confirm Westminster or Camden, the mapped designation, Part 1 position, planning history, listing and title or lease before assessing head height, stair, structure, fire strategy and roofscape.
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 → |
The conversion type depends on the measured roof. Record the pitch, ridge, parapet, structure and usable volume before comparing rooflights, a dormer, hip-to-gable work or a mansard. Match the option to the host building and the verified consent route rather than assuming a particular St John's Wood typology.
Head height must be measured with the proposed floor, insulation and roof build-up included. The useful area, not a postcode rule of thumb, determines whether the space supports the intended room and compliant circulation. Record shallow zones and structural constraints before treating the roof as convertible.
Resolve the staircase at feasibility against the measured floor below and the applicable Building Regulations guidance. Its position can affect usable space, circulation and the fire strategy. A top-floor flat also requires title and lease checks to establish ownership of the roof void before design proceeds.
Develop the fire strategy for the actual building, height, storeys, layout and proposed use using current Building Regulations guidance and competent fire input where required. Do not prescribe a protected stair, door rating, suppression system or secondary escape from the neighbourhood or a generic storey description.
A structural engineer should design the roof alterations from the surveyed construction and load paths. Party Wall procedures apply only if the resulting work is notifiable under the Act; establish wall ownership, bearing details and the relevant adjoining owners before deciding that notices are needed.
If the site is within a mapped conservation area, explain how the proposed roof reads against the significance identified by the applicable Westminster or Camden appraisal. Set-backs, materials, visibility and host-building form are project evidence, not a guaranteed formula for approval.
Local analysis
Where the surveyed building has a parapet, test how a dormer or mansard would read from relevant viewpoints and against the applicable Westminster or Camden appraisal. Set-back, pitch and covering can affect that evidence, but no dimension or material guarantees acceptance. We record the actual roof and explain the proposal rather than relying on a local formula.
A top-floor flat does not use Part 1 householder rights. Check the planning history and proposed work for the public route, then read the title and executed lease to establish whether the roof void is demised and what landlord consent is required. Do not infer ownership or a Licence to Alter from the building label.
Survey the structure, fire separation, acoustics, common stair and any proposed terrace. Party Wall procedures apply only where the designed work is notifiable. We map each public, private and technical decision separately before treating the roof space as convertible.
Draw the staircase against the measured floor below, usable roof volume and current technical guidance before valuing the extra room. The building-specific fire strategy determines the escape route, compartmentation, detection and whether engineered measures are needed; a three-storey description alone does not prescribe the solution.
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, conservation mapping or roof precedent. The councils maintain separate St John's Wood conservation records, so neither the neighbourhood nor NW8 establishes one authority or designation.
For a qualifying dwellinghouse, test the roof work against the applicable Part 1 class, every limitation and condition, planning history and any live Article 4 direction. Conservation-area status adds class-specific limits but does not remove every right; flats do not use Part 1. If an application is required, the statutory non-major target runs from validation and is not an end-to-end promise.
Where the applicable appraisal identifies a roofscape as significant, test the visibility and effect of front, rear or mansard work against that record. Flats do not use Part 1 householder rights, but the planning and landlord routes still depend on the proposed operation, planning history, title and actual lease; establish each separately.
Westminster and Camden publish separate St John's Wood conservation maps and appraisals. If the complete site is designated, use the applicable record to identify the roof forms, chimneys, parapets, views or garden relationships that contribute to its significance.
Check the exact address on the relevant council map for any locally identified building and separately search the National Heritage List. A local heritage record can inform design, but it does not establish statutory listing or a neighbourhood-wide roof rule.
Search the exact address on the National Heritage List and correct council records. Listed-building consent is required only where the proposed roof, structural or stair work affects the special architectural or historic interest of a listed building; it remains separate from planning permission.
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 details of the roof space. We will identify Westminster or Camden, check mapped heritage, title or lease, structure, stair and fire questions, and set out a proportionate drawing route without promising consent.
