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Brent, London

House extension drawings in Brent

House extension drawings in Brent start at £695 including VAT. Brent publishes detailed limits for each extension shape, from rear and side-return to two-storey, and it has 39 Article 4 directions, so the first job is to find out which rules apply to your address.

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    Brick house being extended, with a wide new opening supported over the ground floor

    House extension drawings in Brent: limits by extension type

    The detail is in the Residential Extensions and Alterations Supplementary Planning Document. For a single-storey rear extension it says depth can be up to 6 m attached; 8 m detached, and that depth must not be more than half the garden length, with the retained garden meeting the local plan's amenity standard. Height depends on depth: 4 m height; 3 m / 2.5 m eaves, the lower eaves applying on the boundary once an extension goes beyond the shallower depths.

    Side-return extensions have their own figures. An outrigger extension must not extend more than 3 m; 3.5 m height; 2.5 m eaves, counting depth beyond the outrigger's end wall, height next to it and eaves on the boundary. Where it creates inner rooms the guide wants a minimum 2 m lightwell, measured from the rear wall, so we plan the light before we plan the walls.

    Two storeys are tighter. A two-storey rear extension must be no more than 3 m attached; 4 m detached deep and must not cross a 45 degrees line from the nearest neighbour's habitable-room window. A two-storey side extension is limited to two thirds width; 0.5 m set-back. Each of these numbers is something an officer can measure on your drawings, so we dimension all of them: depth, height, eaves, set-back and the forty-five degree line, each labelled on the plan or section where it applies.

    Finished white-rendered rear house extension with large glazed doors

    Local figures for Brent

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Single-storey rear extensions can be up to 6 metres deep for attached (terraced or semi-detached) homes and up to 8 metres for detached homes, from the original rear wall.6 m attached; 8 m detached—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.16, paras 3.1.2-3.1.3
    Rear extension depth must not be more than half the length of the garden, and the retained garden should meet Local Plan Policy BH13 amenity standards.half the garden length—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.16, para 3.1.4
    Outrigger (side-return) extensions must not extend more than 3 metres beyond the end wall of the outrigger, be no more than 3.5 metres high where adjoining it, and have eaves no higher than 2.5 metres on the boundary.3 m; 3.5 m height; 2.5 m eaves—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.29, paras 3.5.2-3.5.3
    Outrigger extensions that create inner rooms should include a lightwell at least 2 metres deep from the rear wall.2 m lightwell—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.29, para 3.5.4
    Two-storey rear extensions must not be more than 3 metres deep for attached homes or 4 metres for detached homes.3 m attached; 4 m detached—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.21, paras 3.2.3-3.2.4
    Two-storey rear extensions must not cross the 45-degree line taken from the middle of the nearest neighbouring habitable-room window on the original rear wall.45 degrees—brent.gov.uk, Residential Extensions and Alterations SPD 2025, p.21, para 3.2.5
    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
    Conservation areas23 named conservation areas published by the council—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: alterations/extensions to a single dwellinghouse, from 1 Apr 2026548 GBP—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 Brent
    Single-storey rear extension: the permitted development limitsDepth beyond the original rear wall: 3 m (attached) / 4 m (detached) beyond the original rear wall, single storey. Maximum height: 4 m. Within the zone near the boundary: Eaves no higher than 3 m where within 2 m of the curtilage boundary. Larger extension under prior approval: 6 m (attached) / 8 m (detached), single storey, height max 4 m; not on article 2(3) land or an SSSIABCD

    Single-storey rear extension: the permitted development limits

    The house in section with a rear extension; the dashed lines mark the zone near the boundary.

    A · Depth beyond the original rear wall
    3 m (attached) / 4 m (detached) beyond the original rear wall, single storey
    B · Maximum height
    4 m
    C · Within the zone near the boundary
    Eaves no higher than 3 m where within 2 m of the curtilage boundary
    D · Larger extension under prior approval
    6 m (attached) / 8 m (detached), single storey, height max 4 m; not on article 2(3) land or an SSSI

    Why Article 4 matters so much in Brent

    Brent has 39 Article 4 directions, mapped as 162 areas, and 23 conservation areas. A direction can remove permitted development rights that a house extension would otherwise rely on, so the same scheme may need an application on one road and not on the next.

    We read the direction that covers your road, not just the borough summary, and then decide between a Lawful Development Certificate and an application. Where a direction applies, the drawings take on more work, since the officer judges materials, openings and roof shape directly.

    How Brent has been deciding householder cases

    The council decided 879 householder applications in its latest published year, granted 86.6 per cent, and decided 97.2 per cent in time. Only 43.3 per cent of households live in a house and 38.4 per cent own their home, so many homes are flats or rented.

    That mix affects what you need. A leaseholder needs the freeholder's agreement as well as planning, and a flat cannot use householder permitted development. We raise both at quote stage. If you own the freehold of a house, the drawings are the same but the route is simpler. Keeping within the council's limits removes an obvious ground for objection, though we never promise a decision.

    Listed buildings in Brent

    Historic England lists 93 entries in Brent. For a listed house, listed building consent is a separate application, and we draw it with the planning set.

    Our fee, the fees you pay the council, and the process

    Our fee starts at £695 with VAT included, fixed before you commit. The set has existing and proposed plans, elevations and sections, a location plan and a block plan. A householder application costs £548 at the council, and drawings are normally ready about a week after the survey.

    A second chartered technologist checks each sheet before it goes in, and we redraw at no charge until approval if the council asks for changes. Energy limits apply to the new fabric: 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.

    Other extension types and the neighbours

    Brent's guidance is detailed enough that each shape deserves its own page: side return extension drawings in Brent, wraparound extension drawings in Brent and double-storey extension drawings in Brent. The borough summary is at architectural drawings in Brent.

    Next door, Ealing and Harrow read the same national rules through different guidance. The national explanation is on the house extension 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.
    Two-storey rear extension under construction on a semi-detached house
    Every side considered
    Flick across the turntable to spin it.

    Other services in Brent

    House extension drawings nearby

    Questions

    How deep can a rear extension be in Brent?

    Brent's SPD allows single-storey rear extensions up to 6 m attached; 8 m detached from the original rear wall, but never more than half the garden length.

    What are Brent's limits for a side-return extension?

    An outrigger extension must not extend more than 3 m; 3.5 m height; 2.5 m eaves, and where it creates inner rooms it needs a minimum 2 m lightwell from the rear wall.

    How much do house extension drawings cost in Brent?

    From £695 including VAT, fixed up front. The council fee is paid separately.

    Is my Brent house covered by an Article 4 direction?

    The borough has 39 directions. We check your address against them before we quote, and tell you which route applies.

    Sources and dates

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    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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