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Bromley, London

L-shaped dormer drawings in Bromley

Bromley publishes 108 Article 4 directions. We draw L-shaped dormers for Bromley houses for a fixed quote after a free constraints check, VAT included, and start by finding out whether yours is covered.

Fixed quote after a free constraints check

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

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    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 l-shaped dormer drawings

    Nine 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.

    8. Building regulations

      Technical drawings are coordinated with the structural engineer's calculations, the drainage and the planning conditions.

    9. Approval and hand-over

      Building control approval, then a next-steps pack covering the commencement notice, party wall timing and CIL.

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

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    Slate-clad roof extension on a yellow-brick London terraced house

    Bromley design guidance for an L-shaped dormer

    Bromley's guidance is the Urban Design Guide SPD, supported by the Bromley Local Plan. Neither gives a measured limit for an L-shaped dormer that we can quote. The council relies on design judgement, so the drawings carry the argument rather than a number.

    That puts weight on the street scene. We include a contextual elevation showing neighbouring roofs, the position of the new dormer and the cladding, because an officer weighing a dormer with no fixed limit looks at how it sits among the houses beside it.

    We also record the roofs either side and behind, because the officer will compare your dormer with what is already there. Our constraints check includes the planning history, so if neighbouring houses carry approved dormers, their references support the case. If the street has none, a smaller L kept well below the ridge is the stronger proposal, and a short design note explains the reasoning to the case officer.

    Converted loft bedroom with roof windows and a Juliet balcony

    Local figures for Bromley

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Article 4 directions108 Article 4 directions published by the council—planning.data.gov.uk
    Conservation areas47 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries412 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Householder decisions1,609 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted78.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time89.1 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder appeals decided by the Planning Inspectorate502 householder appeals decideddecision dates 1 Jul 2021 to 30 Jun 2026assets.publishing.service.gov.uk
    Householder appeals allowed37.6 % of householder appeals alloweddecision dates 1 Jul 2021 to 30 Jun 2026assets.publishing.service.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 Bromley

    Householder applications by street in Bromley

    Streets in Bromley with the most householder applications, and the share approved
    StreetApplicationsApproved
    Petts Wood Road3981%
    Hayes Way3667%
    Crescent Drive3472%
    Village Way3281%
    Pickhurst Rise3187%
    Hayes Chase3083%
    Charterhouse Road2788%
    Farnaby Road2788%
    Kings Hall Road2591%
    St Paul's Wood Hill2588%
    Eden Park Avenue2477%
    Kent House Road2490%
    Broxbourne Road2391%
    Clock House Road2386%
    Elmstead Lane2381%
    Counts of householder applications by street; no individual applications are shown. Streets with fewer than five applications are left out.Source: GLA Planning London Datahub, householder applications, all years held. Contains public sector information licensed under the Open Government Licence v3.0. Contains OS data © Crown copyright and database right 2026.
    Loft enlargement in section: the permitted development limitsExtra roof volume allowed: 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume. Set-back from the eaves: Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension). Height limit: No part higher than the highest part of the existing roofABC

    Loft enlargement in section: the permitted development limits

    A dormer on the rear slope, with the limits that decide whether it needs planning permission.

    A · Extra roof volume allowed
    40 m³ (terrace house) / 50 m³ (any other house) additional roof volume
    B · Set-back from the eaves
    Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension)
    C · Height limit
    No part higher than the highest part of the existing roof

    Article 4 directions and protected areas

    The council has 108 Article 4 directions and 47 conservation areas, with 412 Historic England list entries. In an area under a direction, roof rights may be withdrawn, and in a conservation area the national rule applies: Class B roof enlargements are not permitted development on article 2(3) land.

    A direction can cover a single street or a whole estate, so we find out first. If your house is free of all of them we can talk about permitted development. If not, we move directly to a householder drawing set.

    About 51 per cent of the borough is Green Belt. That seldom limits a roof alteration to an existing house, but it matters if you also plan an extension.

    The appeal record

    The Planning Inspectorate decided 502 householder appeals in Bromley and allowed 37.6 per cent. Most refusals taken to appeal have therefore been upheld.

    The sensible conclusion is that Bromley refusals tend to stick. We want a scheme officers can approve on the first submission, which means the restrained L, not the maximum one.

    Decisions and the housing stock

    Bromley decided 1,609 householder applications in its latest year, a large caseload, and granted 78.6 per cent. It decided 89.1 per cent within eight weeks or an agreed extension.

    About 68.6 per cent of households live in a house or bungalow and 68.5 per cent own their home. A house is the usual home here, though only some have the two-storey outrigger an L-shaped dormer needs.

    The permitted development tests

    Where the rights remain, the volume limit is: 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume. Height must satisfy: No part higher than the highest part of the existing roof. The L-shape works because of this: Eaves-retention and 0.2 m set-back do not apply where the enlargement joins the original roof to the roof of a rear or side extension.

    We calculate the volume on the model and give you the answer before you commit to a design. If the L is too large, we show the reduced version and the planning alternative side by side.

    Shared structure, stairs and fire safety

    A shared roof brings notices: Party structure notice at least 2 months before work. The stair allowance is: Loft conversions where 2.0 m cannot be achieved: 1.9 m at the centre of the stair, 1.8 m at the side (half width). For a larger loft: New storey above 4.5 m by loft conversion: protect the full escape route with fire-resisting doors (min E 20) and partitions (min REI 30).

    These go into the building regulations drawings in Bromley, and the party wall notices service handles the notices.

    Detached houses avoid the shared-wall question, but the stair and fire rules apply to every Bromley loft, whatever the house type.

    Cost and next steps

    For a fixed quote after a free constraints check, VAT included, you receive plans, the roof section, elevations and location and block plans. A colleague holding MCIAT, never the drafter, reads every sheet before issue, and requested changes cost you nothing to redraw until approval.

    For a smaller roof see dormer loft conversion drawings in Bromley. The overview is architectural drawings in Bromley, with Lewisham and Croydon close by.

    What you receive

    Planning drawing sheet for a rear extension with plans, elevations and sections
    Sample drawing. Planning drawings for a rear extension: plans, elevations and sections on one sheet set.
    Brick cottage with a tiled roof, chimneys and a front dormer window
    Storey by storey
    Move up and down — the car travels between floors.

    Other services in Bromley

    L-shaped dormer drawings nearby

    Questions

    Is my Bromley house in an Article 4 area?

    Bromley publishes 108 directions, so check the address. We do this free before quoting.

    Does Bromley set an L-shaped dormer limit?

    There is no measured limit we can cite in its Urban Design Guide SPD, so design judgement and the street scene carry the decision.

    How often do Bromley householder appeals succeed?

    The Inspectorate allowed 37.6 per cent of 502 cases.

    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.

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