020 7864 7245Request a fixed quote

Kensington and Chelsea, London

Flat conversion drawings in Kensington and Chelsea

Kensington and Chelsea charges a zoned community infrastructure levy with some very steep rates, so the layout of a conversion decides whether it pays. We prepare flat conversion drawings in Kensington and Chelsea from £1,195 including VAT, as MCIAT chartered architectural technologists, and we test each scheme against the Local Plan 2024 (New Local Plan Review) and the levy zone before it is priced.

From £1,195 (VAT included)

  • MCIAT chartered
  • £2m PI insured
  • LABC Partnered
  • Fixed fees, VAT included

Request a fixed quote

We use it to check conservation areas and constraints.
Pick the council that decides your application.
A few lines: what you want to build, and anything the council has already said.
Add photos or drawings

Drop files here or choose from your device

PDF, JPG, PNG, DWG · up to 10 files, 90 MB in total

    Architectural model of a four-storey London stucco townhouse in its terrace, with a portico, area railings, sash windows, a cornice and chimney stacks
    The house as it stands: four storeys over a lower ground floor.Existing Proposed worksAn illustrative model, built for this page.

    How we work on flat conversion drawings

    Seven steps from first call to approval.

    The same model cut through the middle: every floor, the stair, the chimney breasts, the new mansard, rear extension and basement in section
    Section through the model: every floor on one datum.

    1. Enquiry and constraints check

      We check the property against conservation areas, listed status, Article 4 directions, tree preservation orders, flood zone and planning history. We choose the right route and send a fixed quote.

    2. Measured survey

      We survey the house on one datum: rooms, levels, boundaries, drains, trees and the neighbours' windows that the 45° and 25° tests depend on.

    3. Design options

      We model the house in Revit and show you options in 3D and plan, with the planning strategy and the precedents in your street.

    4. Design frozen

      You choose an option in writing. Nothing changes after this without your say.

    5. Independent check

      A second chartered technologist checks every sheet against the council's validation checklist and the policy. A senior review signs it off before anything is submitted.

    6. Submission

      We prepare the forms, certificates, fee and documents and submit through the Planning Portal.

    7. Officer liaison

      We answer the planning officer and make any amendments within five working days, at no charge until approval.

    Free redraws until approval. Every drawing set is checked independently, and the checker is never the person who drew it.

    Request a fixed quote
    Pencil resting on a dimensioned technical drawing beside a scale rule

    The Kensington and Chelsea plan, levy and basement guidance

    The development plan here is the Local Plan 2024 (New Local Plan Review), adopted in 2,024. The nationally described space standard applies to the flats you create, so a conversion has to prove each one is big enough in the same way a new building would.

    Money is the second test. The levy is set by the council's charging schedule, which divides the borough into lettered zones, from Zone A, where the residential rate is above a thousand pounds a square metre, down to two zones that pay nothing. The full list of zone rates is in the table, and the exemption for small additions does not apply where a new dwelling is created.

    Because the same house can sit in a very expensive or a nil-rated zone, we establish the zone from the address on day one. Where a lower floor is to become its own home, the council's Basements SPD also applies, and it is best read before any basement idea is promised. Our flat conversion drawings guide describes what a full set contains.

    Rear view of brick terraced houses in London with slate roofs and chimney stacks along the shared roofline

    Local figures for Kensington and Chelsea

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Minor application decisions840 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Minor applications granted93.2 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Minor applications decided in time93.7 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted93.7 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Listed building entries1,350 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Conservation areas39 named conservation areas published by the council—planning.data.gov.uk
    Article 4 directions84 Article 4 directions published by the council—planning.data.gov.uk
    Tree preservation orders4,560 tree preservation orders published by the council—planning.data.gov.uk
    Mayoral CIL charging band1 MCIL2 charging band (1-3)—london.gov.uk
    Mayoral CIL rate (indexed)96.97 £/m² (indexed, permissions granted in 2026)—london.gov.uk
    Borough CIL residential rate£1,158.30/m² (Zone A); £911.20/m² (Zone B); £664.09/m² (Zone C); £416.99/m² (Zone D); £293.44/m² (Zone E); £169.88/m² (Zone F); Nil (Zones G Earl's Court and H Kensal)indexed rate for permissions granted 1 Jan to 31 Dec 2026 (Residential C3 & short-term lets)rbkc.gov.uk
    Change of use of a building to one or more separate dwellinghouses, not more than 10: per dwellinghouse, from 1 Apr 2026610 GBP per dwelling—ribblevalley.gov.uk

    A blank value means the figure has not been published, not that there are none. Check your own address with the council.

    Councils bordering Kensington and Chelsea
    Building regulations, layer by layerPart A: structure: Approved Document A: Structure, 2004 edition incorporating 2004, 2010 and 2013 amendments. Part B: fire safety: All dwellings: fire detection and alarm system minimum Grade D2 Category LD3 (BS 5839-6), mains-operated smoke alarms to BS EN 14604. Part L: insulation: New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4. Part K: stairs: 2.0 m clear headroom over stairs. Full plans application: Building control body must decide a full plans application within 5 weeks, or longer if agreed in writingPart A: structurePart B: fire safetyPart L: insulationPart K: stairsFull plans applicationABCDE

    Building regulations, layer by layer

    The Approved Documents that shape most house projects, from structure to the application itself.

    A · Part A: structure
    Approved Document A: Structure, 2004 edition incorporating 2004, 2010 and 2013 amendments
    B · Part B: fire safety
    All dwellings: fire detection and alarm system minimum Grade D2 Category LD3 (BS 5839-6), mains-operated smoke alarms to BS EN 14604
    C · Part L: insulation
    New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4
    D · Part K: stairs
    2.0 m clear headroom over stairs
    E · Full plans application
    Building control body must decide a full plans application within 5 weeks, or longer if agreed in writing

    How the council decides smaller schemes

    A conversion into two or three flats is a minor application. In the latest twelve months the council decided 840 of them, more than its 664 householder decisions, and granted 93.2 per cent. Within eight weeks or an agreed extension, 93.7 per cent were decided.

    The householder grant rate is 93.7 per cent, close to the minor figure. The sharper risk is heritage, since many houses sit in a conservation area or carry a listing, so we check both before drawing.

    That is why our drawings show the existing front elevation in detail, mark any original features and separate what is retained from what changes. A case officer can then see in one sheet that the street scene is preserved.

    Heritage, trees and directions

    The borough lists 1,350 building entries and 39 conservation areas, with 84 Article 4 directions and 4,560 tree preservation orders. Green belt covers 0 per cent of it, so that constraint never arises.

    In a house that is listed, turning one home into two usually needs listed building consent as well as planning permission, because internal walls, stairs and floors are protected. We check the list entry and tell you before you commit to design fees whether the plan is realistic.

    A tree in a rear garden affects the amenity space shared out between flats, so we plot trees on the survey drawing. The Kensington and Chelsea area page sets out the borough's constraints in more detail.

    The numbers behind the decision to convert

    The average terraced house in the borough costs about £2,429,086 and the average flat about £971,688. The twelve-month change in the average price is -14.1 per cent, which puts the cost of a conversion in sharper view against the value it adds.

    Only 17 per cent of households live in a house, and 31.7 per cent own their home, so your house is unusual for the borough and a conversion is scrutinised accordingly.

    On top of the borough levy the Mayor charges for new floor area. The borough sits in band 1, with an indexed rate of £96.97 per square metre this year, and the planning fee is £610 for each flat created.

    What we draw

    Sound and height are checked at the same time as space. The London Plan asks for a floor-to-ceiling height of 2.5 m across most of each flat, which can rule out a low lower-ground floor. Approved Document E sets the sound targets between flats, and we draw the floor and wall build-ups that reach them. You receive existing and proposed floor plans, elevations, sections, a block plan and a schedule of areas by flat. Once planning is secured, building regulations drawings follow. For a neighbouring comparison, see flat conversion drawings in Westminster.

    What you receive

    Building regulations section drawing showing the construction build-up
    Sample drawing. Building regulations section showing construction build-up for a building control check.
    Upper floors of a large yellow-brick Victorian house in London with chimney pots
    Unit by unit
    Move up and down — the nearest units slide out.

    Other services in Kensington and Chelsea

    Flat conversion drawings nearby

    Questions

    Why is the levy so important in Kensington and Chelsea?

    The borough's residential rate runs from over a thousand pounds a square metre in Zone A down to nil in two zones, so the address changes the cost enormously.

    Do I need listed building consent to split a listed house?

    Often yes, because internal alterations to a listed house need consent as well as planning permission. We check the list entry first.

    Is green belt a concern in this borough?

    No. The council's green belt share is 0 per cent.

    What does the planning fee come to for two flats?

    It is £610 for each flat created, so twice that figure for two.

    Sources and dates

    City of London skyline glowing at dusk across the Thames under a dramatic orange sky

    Tell us about your property.

    We check the constraints, then send a fixed fee. Messages before 3pm get a reply the same working day.

    Request a fixed quoteCall 020 7864 7245WhatsApp