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Brent, London

Dormer loft conversion drawings in Brent

Dormer loft conversion drawings for a Brent house start at £695 including VAT. Brent sets a hard height line and a generous width: no dormer may rise above the original ridge, while a rear dormer can run to the full width of the original roof if it is set up from the eaves.

From £695 (VAT included)

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    Converted loft bedroom with roof windows and a Juliet balcony

    Brent's measured rules for a dormer

    Brent's Residential Extensions and Alterations SPD sets measured rules for dormers. The first is a ceiling: no dormer may be higher than the original ridge. The second concerns the front, where a dormer is acceptable only if dormers are a common feature of the street.

    The third is the rear dormer rule, which the SPD states as full width; 0.2 m above eaves. In plain terms, you may use the whole width of the original roof, and the dormer must start above the eaves by at least the stated margin.

    We use this to get the most from a narrow terrace. The room can reach both party walls where permitted development rights allow it, with the height held below the ridge line. Under those rights the dormer must also leave the original eaves in place and sit back from them: 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). When the house has lost its rights, the SPD figures tell us what an officer will treat as reasonable.

    Brick cottage with a tiled roof, chimneys and a front dormer window

    Local figures for Brent

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Rear dormers can be up to the full width of the original roof and must be set up at least 0.2 metres from the eaves.full width; 0.2 m above eaves—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.34, paras 3.6.7-3.6.8
    Conservation areas23 named conservation areas published by the council—planning.data.gov.uk
    Article 4 directions39 Article 4 directions published by the council—planning.data.gov.uk
    Article 4 direction areas162 Article 4 direction area polygons published by the council—planning.data.gov.uk
    Listed building entries93 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Householder decisions879 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted86.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time97.2 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Households living in a house43.3 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.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
    Class B, para B.1(c)No enlargement beyond the plane of a roof slope that forms the principal elevation and fronts a highway—legislation.gov.uk
    Class B, para B.1(f)Class B roof enlargements are not permitted development on article 2(3) land—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 Brent
    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 flats in Brent

    Brent has published 39 Article 4 directions, mapped as 162 separate areas, plus 23 conservation areas. A direction can withdraw the right to alter a roof or a front elevation, so the address check comes before any design.

    Only 43.3 per cent of Brent households live in a house or bungalow. Flats do not carry the householder permitted development rights that houses do, so a dormer on a flat roof or a converted maisonette is a planning application from the start. We confirm the type of dwelling before we quote a route.

    Historic England lists 93 entries in the borough. A listed house needs separate consent for roof changes, and the drawings for that consent are a different package.

    Brent householder decisions in numbers

    In its latest published year Brent decided 879 householder applications and granted 86.6 per cent. 97.2 per cent were decided within eight weeks or an agreed extension.

    The figures cover every kind of householder project, not only dormers, so they describe the council rather than your roof. We use them to set a timetable and to talk through risk with you, never to promise an outcome.

    Where the design stays within permitted development, a Lawful Development Certificate gives the same assurance with a proof you can show a buyer. We advise which route fits when we have seen the roof.

    Finish and windows are part of that judgement. The national condition on materials is that they are Exterior materials similar in appearance to the existing house, and for side windows in the dormer cheek: Upper-floor side windows obscure-glazed and non-opening below 1.7 m above floor. On a terrace the side windows rarely matter, but on a semi they face the neighbour, so we plan them early.

    Brent dormer loft conversion drawings and what you get

    The set covers the existing and proposed floor plans, the stair, the roof in section with the dormer and its build-up, and every elevation. It comes with the location and block plans the council needs for an application.

    A dormer that runs the full width of a roof is a large flat structure, so insulation matters. The target for new roof elements is 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. We put the build-up on the section early, because the extra depth raises the dormer and the ridge limit is fixed.

    The price is £695 including VAT, quoted before you commit. A second MCIAT chartered architectural technologist checks every sheet, and we redraw at no charge if the council asks for changes.

    Other roof work in Brent, and nearby boroughs

    If the roof is better suited to a simpler scheme, see loft conversion drawings in Brent, or Velux loft conversion drawings in Brent for rooflights only. A wider form is covered by L-shaped dormer drawings in Brent.

    Neighbouring councils apply different tests. Compare dormer loft conversion drawings in Ealing, in Harrow and in Barnet. The borough overview is at architectural drawings in Brent, and the national rules are on the dormer loft conversion drawings hub.

    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.
    Rear view of brick terraced houses in London with slate roofs and chimney stacks along the shared roofline
    Storey by storey
    Move up and down — the car travels between floors.

    Other services in Brent

    Dormer loft conversion drawings nearby

    Questions

    How high can a dormer be in Brent?

    No higher than the original ridge, according to the council's Residential Extensions and Alterations SPD. The roof build-up counts towards that height, so we draw it early.

    Can a Brent rear dormer be full width?

    The SPD says rear dormers can be up to the full width of the original roof, set up from the eaves; it states the rule as full width; 0.2 m above eaves. Permitted development rights and any conservation area or Article 4 direction still apply.

    Can I add a dormer to a flat in Brent?

    Householder permitted development rights belong to houses, not flats, so a dormer on a flat normally needs planning permission. We check the type of dwelling first.

    What do dormer loft conversion drawings cost in Brent?

    From £695 including VAT, fixed up front. The council's own fee is separate.

    Sources and dates

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