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Lewisham, London

House extension drawings in Lewisham

House extension drawings for a Lewisham home start at £695 including VAT. The council's Alterations and Extensions SPD sets a general depth for terraced and semi-detached houses and a separate test for the boundary, so a Lewisham extension is designed around two numbers before anything else.

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    Finished white-rendered rear house extension with large glazed doors

    House extension drawings in Lewisham: depth, boundary height and daylight

    Lewisham's guidance says rear extensions should generally be no more than 3 m deep for terraced or semi-detached houses, with more possible for detached houses or large plots. They should never be more than half the depth of the original garden, which on a short Victorian plot can be the tighter limit.

    The boundary is where neighbours feel an extension most. The SPD's test is 3 m long / 3 m high; 2.5 m on boundary if longer, so the height of the wall on the party line is controlled as well as the depth. A flat roof with a thin parapet and a pitched roof sloping away from the neighbour come out quite differently under that test.

    Daylight is checked with a line of 45 degrees upwards and sideways from the centre of the neighbour's affected window. Development that is both higher and wider than both lines may cause unacceptable loss, and we plot the two lines on the drawings so the officer can see the result.

    Two-storey rear extension under construction on a semi-detached house

    Local figures for Lewisham

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Rear extensions should generally be no more than 3 m deep for terraced or semi-detached houses (deeper possible for detached or large plots) and never more than half the depth of the original garden.3 m—lewisham.gov.uk, Lewisham Alterations and Extensions SPD 2019, p.28, para 4.2.3
    Extensions up to 3 m long should be no more than 3 m high on the boundary; longer than 3 m and over 2.5 m high on the boundary is unlikely to be supported.3 m long / 3 m high; 2.5 m on boundary if longer—lewisham.gov.uk, Lewisham Alterations and Extensions SPD 2019, p.28, para 4.2.3
    45 degree daylight guide: lines at 45 degrees upwards and sideways from the centre of the neighbour's affected window; development higher and wider than both lines may cause unacceptable daylight loss.45 degrees—lewisham.gov.uk, Lewisham Alterations and Extensions SPD 2019, p.22, para 3.3.15
    Infill extensions should generally be no more than 3 m deep for terraced or semi-detached houses, single storey only, with ridge at least 2-3 brick courses below first-floor window sills.3 m—lewisham.gov.uk, Lewisham Alterations and Extensions SPD 2019, p.38, paras 4.5.2-4.5.3
    Infill or wraparound extensions up to 3 m long should be no more than 3 m high; over 3 m long and over 2.5 m high on the boundary is unlikely to be supported; L-shaped extensions should leave a path of at least 1 m to the rear garden.3 m / 2.5 m / 1 m path—lewisham.gov.uk, Lewisham Alterations and Extensions SPD 2019, p.38-39, para 4.5.3; p.31, para 4.2.3 L-shaped
    Two or more storey side extensions should be set in at least 1 m from the boundary and back at least 1 m from the front elevation (2 m back if built to the boundary), with the roof set down from the main ridge.1 m in; 1 m back (2 m if on boundary)—lewisham.gov.uk, Lewisham Alterations and Extensions SPD 2019, p.36, para 4.4.6
    Conservation areas30 named conservation areas published by the council—planning.data.gov.uk
    Article 4 directions57 Article 4 directions published by the council—planning.data.gov.uk
    Listed building entries367 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    worldHeritageSites1 World Heritage Sites intersecting the LPA boundary—planning.data.gov.uk
    Green Belt share of the council area0 % of council area covered by green-belt polygons—planning.data.gov.uk
    Householder decisions578 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted89.4 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time95.2 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Larger home extension prior approvals granted2 decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Larger home extension prior approvals refused46 decisions2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Domestic gardens share of land (GLUD 2005)31.1 % of land that is domestic garden (GLUD 2005)2005data.london.gov.uk
    GPDO 2015 Sch 2 Pt 1 Class A, para A.1(f)(i)3 m (attached) / 4 m (detached) beyond the original rear wall, single storey—legislation.gov.uk
    Householder: alterations/extensions to a single dwellinghouse, from 1 Apr 2026548 GBP—ribblevalley.gov.uk
    Supplementary planning documentAlterations and Extensions SPD2019lewisham.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 Lewisham
    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

    Side infill and wraparound extensions in Lewisham

    Infill extensions beside an outrigger should generally be no more than 3 m deep for terraced or semi-detached houses and single storey only, with the ridge two or three brick courses below the first-floor window sills. That is a small detail that decides whether a roof can slope or has to be flat.

    For wraparounds the SPD combines its tests: 3 m / 2.5 m / 1 m path. L-shaped extensions are asked to leave a path to the rear garden, a point that is easy to lose when the kitchen is drawn edge to edge.

    See our wraparound extension drawings in Lewisham for how those limits combine on a typical plot.

    Two storeys and the pre-application route

    The council will only consider two-storey rear extensions where exceptional design quality is shown, and it advises pre-application discussion. Side extensions of two or more storeys should be set back 1 m in; 1 m back (2 m if on boundary), with the roof set down from the main ridge.

    Because of that, we can draw a ground-floor scheme and a first-floor scheme side by side for Lewisham clients, so the choice is made on drawings and not on hope. Our double-storey extension drawings in Lewisham describe that comparison.

    Conservation areas, Article 4 directions and listed houses

    Lewisham has 30 conservation areas, 57 Article 4 directions and 367 listed building entries. The national heritage list also records 1 World Heritage Site crossing the borough boundary. A large number of Article 4 directions means the permitted development right you expect for your street may have been removed.

    Where none applies, a single-storey rear extension may follow the national rule: 3 m (attached) / 4 m (detached) beyond the original rear wall, single storey. A Lawful Development Certificate in Lewisham records that. The borough has no Green Belt, at 0 per cent.

    How Lewisham decides extension applications

    In its latest published year the council decided 578 householder applications, granted 89.4 per cent and decided 95.2 per cent in time. On larger home extension prior approvals it granted 2 and refused 46.

    Those counts are for the whole borough. With refusals far outnumbering grants, a full householder application, at £548 to the council, is worth weighing for a deeper extension.

    Domestic gardens cover around 31.1 per cent of the borough's land, so the SPD's half-the-garden limit is worth measuring before the design starts.

    What the drawings include and what they cost

    A Lewisham extension set shows existing and proposed floor plans, elevations and sections, plus the location and block plans. Drawings start at £695 with VAT included, a second MCIAT chartered technologist checks every sheet, and we redraw at no charge if the council asks for changes.

    For the borough as a whole, see architectural drawings in Lewisham. Neighbouring owners in Greenwich or Bromley can compare their own councils' figures.

    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.
    House extension under construction with scaffolding, new glazed doors and building materials
    Every side considered
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    Questions

    How deep can a rear extension be in Lewisham?

    Lewisham's Alterations and Extensions SPD says generally no more than 3 m for terraced and semi-detached houses, and never more than half the depth of the original garden.

    Does Lewisham allow two-storey rear extensions?

    Only where exceptional design quality is demonstrated, and the council advises pre-application advice first.

    What is Lewisham's rule on extensions at the boundary?

    The SPD says 3 m long / 3 m high; 2.5 m on boundary if longer. Longer and higher than that is unlikely to be supported.

    How much do house extension drawings cost in Lewisham?

    From £695 including VAT, fixed up front. The council's householder fee, £548, is paid separately.

    Sources and dates

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