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Barnet, London

Hip-to-gable loft conversion drawings in Barnet

Barnet has long streets of semi-detached houses with hipped roofs, and a hip-to-gable loft conversion is a common way to turn one into a proper bedroom and bathroom. We prepare hip-to-gable loft conversion drawings in Barnet as MCIAT chartered architectural technologists, and we give you a fixed quote after a free constraints check, VAT included.

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 hip-to-gable loft conversion 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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    Brick cottage with a tiled roof, chimneys and a front dormer window

    How Barnet treats hip-to-gable extensions

    Barnet's guidance for householders sits in the Sustainable Design and Development Guidance SPD, Part 4: Guidance on residential extensions and alterations, under the Barnet Local Plan 2021-2036, adopted in 2,025. Its Part 4 covers residential extensions and alterations, which is where a roof change is tested when permitted development does not apply.

    In practice the question is balance. A gable beside a hipped neighbour can look lopsided and the pair of houses loses its symmetry, so the first thing we do is look at the next-door roof, and the roofs further down the street, to see what the pattern is. If the neighbour already has a gable, the case is easier to make. If both of you are hipped, we look hard at the alternatives and show you each in elevation.

    For houses where the right exists, national rules apply: the usual set-back is waived for this type of work, as the order says: Eaves-retention and 0.2 m set-back conditions do not apply to a hip-to-gable enlargement. The cap on new roof volume remains: 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume.

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

    Local figures for Barnet

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Householder appeals decided by the Planning Inspectorate413 householder appeals decideddecision dates 1 Jul 2021 to 30 Jun 2026assets.publishing.service.gov.uk
    Householder appeals allowed50.6 % of householder appeals alloweddecision dates 1 Jul 2021 to 30 Jun 2026assets.publishing.service.gov.uk
    Conservation areas16 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries651 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Article 4 directions15 Article 4 directions published by the council—planning.data.gov.uk
    Tree preservation orders718 tree preservation orders published by the council—planning.data.gov.uk
    Householder decisions1,361 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted80.2 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time95.1 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    GPDO 2015 Sch 2 Pt 1 Class B, para B.1(d)40 m³ (terrace house) / 50 m³ (any other house) additional roof volume—legislation.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 Barnet

    Householder applications by street in Barnet

    Streets in Barnet with the most householder applications, and the share approved
    StreetApplicationsApproved
    Wolmer Gardens4282%
    Hampden Way3686%
    Oakleigh Park South3677%
    Marsh Lane3591%
    Millway3493%
    Sturgess Avenue3494%
    Uphill Road3273%
    Chanctonbury Way3190%
    Oakleigh Road North3079%
    Woodlands3076%
    Laurel Way2976%
    Mount Pleasant2880%
    Arlington Road2780%
    Berkeley Crescent27100%
    Longland Drive27100%
    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

    Barnet appeals, designations and trees

    Barnet's appeal record is useful evidence. The Planning Inspectorate decided 413 householder appeals in the borough and allowed 50.6 per cent. About half of challenges to refusals therefore succeed, which tells us that a refusal here is not always the end.

    The borough has 16 conservation areas, 651 listed buildings and 15 Article 4 directions covering 48 mapped areas. In a conservation area the national rule is: Class B roof enlargements are not permitted development on article 2(3) land.

    Trees are a real factor. The council records 718 tree preservation orders and 3,219 protected zones, and around 28 per cent of Barnet is green belt, so we check the boundary on each address.

    Householder decisions in Barnet

    The council decided 1,361 householder applications in the latest year, granting 80.2 per cent, with 95.1 per cent decided in eight weeks or an agreed extension. It is a large volume for a single authority.

    Past decisions on roofs like yours are the better guide. We study the reports for roofs like yours and shape the drawings to meet the points that were raised, such as the side window, the flank wall materials and the proximity to the boundary.

    If a refusal looks likely, we say so before you commit to a full design.

    What the drawings must prove

    Two more national conditions apply. The enlargement may not go beyond the walls of the house: No part of the enlargement may extend beyond the outside face of any external wall of the original house (except where joining a rear or side extension roof). And on the street side: No enlargement beyond the plane of a roof slope that forms the principal elevation and fronts a highway. A semi on a corner plot can fail the second test even when its neighbour is fine.

    Inside, the stair is crucial. Where headroom is short: 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). The new storey also needs a protected route: 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).

    Our sections and elevations show each figure, so a building control officer can tick them off without asking you for more.

    Fees and the Barnet levy

    We quote a fixed fee after a free constraints check, VAT included, and redraw free if the council asks for changes. A hip-to-gable has no list price because the roof and the route vary.

    The Mayoral levy for Barnet is in band 2, at £72.73 per square metre this year, and the borough levy is £361.44/m² indexed 2026 (schedule rate £300/m², residential incl. C2, C3, C4 and sui generis HMOs). Your next-steps pack says whether a charge reaches your loft.

    A refusal is not the end in Barnet, as the appeal record shows, but an appeal costs months. We would rather get the drawing right first: the survey captures the ridge, the party wall and the neighbour's roof on one datum, and a second chartered technologist checks the set before it goes in. Drawings are normally ready about a week after the survey.

    Related services and neighbouring boroughs

    A rear dormer often accompanies the gable, so see dormer loft conversion drawings in Barnet and loft conversion drawings in Barnet. The overview is architectural drawings in Barnet.

    We also work in Haringey, Enfield and Brent. The service guide is hip-to-gable loft conversion drawings.

    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.
    Slate-clad roof extension on a yellow-brick London terraced house
    Storey by storey
    Move up and down — the car travels between floors.

    Other services in Barnet

    Hip-to-gable loft conversion drawings nearby

    Questions

    Does Barnet allow hip-to-gable loft conversions?

    Yes, either as permitted development or by application. The guidance is the Sustainable Design and Development Guidance SPD, Part 4: Guidance on residential extensions and alterations, and the neighbouring roofs on your street are the first thing we read.

    How many householder appeals are allowed in Barnet?

    50.6 per cent of 413 householder appeals decided.

    Do I need planning permission for a hip-to-gable in a Barnet conservation area?

    Yes. Class B roof enlargements are not permitted development on article 2(3) land, and the borough has 16 conservation areas.

    What is the volume limit for permitted development?

    40 m³ (terrace house) / 50 m³ (any other house) additional roof volume.

    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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