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Merton, London

Garden room drawings in Merton

Garden room drawings in Merton start at £495 including VAT. In a borough where 60.4 per cent of households live in a house and the average detached home costs £2,338,085, a garden office or studio is a serious investment, and the drawings are what let you build it with confidence.

From £495 (VAT included)

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  • 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 garden room 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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    Finished white-rendered rear house extension with large glazed doors

    Garden rooms and Merton's planning documents

    Merton has not published a measured limit for garden buildings that we can quote, so the national order sets the envelope. The borough's documents matter in a different way: the Merton Local Plan 2024 governs the design standard if an application is needed, and the Small sites toolkit SPD and Borough Character Study SPD describe how infill and character are judged.

    That makes Merton a borough where the neighbourhood is the benchmark. A garden room in Wimbledon's leafy back gardens is read against its surroundings, and one in Mitcham's or Morden's smaller plots against theirs. We draw the elevation with the neighbouring fences and outbuildings in view so the officer sees the comparison without asking.

    Digging down is a separate topic. The borough's Basement and subterranean SPD applies to basements, so a garden room should stay on a slab unless you want that subject handled in its own application.

    Merton is also one of the boroughs where houses in multiple occupation are controlled by an Article 4 direction. A garden room is not an HMO, but the same attention to use applies: the drawings show one room for one purpose, with power and light but no cooking or sleeping provision.

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

    Local figures for Merton

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Households living in a house60.4 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Average price, detached2,338,085 GBP2026-07publicdata.landregistry.gov.uk
    Conservation areas28 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries243 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Registered parks and gardens4 registered parks and gardens intersecting the LPA boundary (Historic England)—planning.data.gov.uk
    Green Belt share of the council area0 % of council area covered by green-belt polygons—planning.data.gov.uk
    Householder applications granted92.9 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time85.2 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    GPDO Sch 2 Pt 1 Class E, para E.1(e)Max 2.5 m if within 2 m of a boundary; otherwise 4 m dual-pitched roof or 3 m any other roof—legislation.gov.uk
    Class E, para E.1(f)2.5 m—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 Merton
    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

    Heritage and trees in Merton gardens

    Merton lists 28 conservation areas and 243 listed building entries, plus 4 registered parks and gardens, which is why some of its large gardens carry extra care. If a property sits in a conservation area the order is firm: On article 2(3) land, no outbuilding between a side wall and the boundary.

    For the listed houses the national rule is plain: Garden buildings within the curtilage of a listed building are not permitted development. In those cases we prepare the application with a short heritage note instead of a certificate.

    The borough has no Green Belt share to speak of (0 per cent), so openness policy rarely enters the discussion; the weight falls on character and neighbours.

    Do you need permission for a garden room in Merton?

    Most Merton garden rooms start as permitted development. The limits are Max 2.5 m if within 2 m of a boundary; otherwise 4 m dual-pitched roof or 3 m any other roof, with eaves no higher than 2.5 m. On layout the rule is: Single storey only; not forward of the principal elevation. A detached house with a deep garden has the most freedom; a semi with a narrow plot has the least.

    When the design exceeds them, a householder application is next. Merton decided 759 householder applications, granted 92.9 per cent and decided 85.2 per cent in time, so allow for the longer end of the range. Our planning drawings in Merton cover the submission.

    A lawful development certificate in Merton gives a written record for a compliant room, which is useful on a sale.

    A practical point for semi-detached owners: the order measures height from the natural ground level beside the building, and cover is counted across every outbuilding already on the plot. We list existing sheds, greenhouses and patios on the survey so the total is right before you commit to a footprint.

    Building control, price and process

    A garden office is usually exempt from Building Regulations: Detached building up to 15 m² with no sleeping accommodation is exempt. The larger class applies up to a bigger footprint with a distance test. A bed for overnight guests changes the picture, and our building regulations drawings in Merton deal with those rooms.

    The fee is £495, VAT included, and fixed before work starts. The pack contains the site plan, plans, elevations, section and a 3D view.

    See the garden room drawings overview for national rules or the architectural drawings in Merton page for everything else. Redraws are free until approval if the council asks for changes, and we make no promise on the decision.

    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
    Flick across the turntable to spin it.

    Other services in Merton

    Garden room drawings nearby

    Questions

    Does Merton have its own size limit for garden rooms?

    We have not found one in its published guidance. The national height, eaves and cover limits apply, and the council judges any application against its character policies.

    Can I build a garden room in a Wimbledon conservation area?

    Often, provided it respects the side-of-house restriction and is not within the curtilage of a listed building. We check your address first.

    How long does a Merton householder application take?

    The council decided 85.2 per cent of householder cases within its target period, so a fair share run over. We give the likely route and timing in the quote.

    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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