Single-storey, double-storey, rear and side extension drawings for Merton homes — measured to Merton Council's design guidance, delivered in days and revised free until your decision, with a free approval-odds check before you commit.
Merton Council granted 88% of the householder planning decisions it made in its latest published year — 1 point above the 87% England-wide householder average. The wooded, low-density character of Wimbledon Village and the Common caps bulk and roof enlargement on many plots, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901), Edwardian (1901–1910) and interwar (1918–1939) housing stock sets the design brief on most streets.
The permitted-development ceilings are fixed: 40m³ of new roof volume for a terraced loft and 50m³ for a semi or detached house under Class B, plus a 3m single-storey rear extension on a terrace or 4m on a detached house under Class A. Merton carries at least one Article 4 direction, and conservation areas including Wimbledon Village, John Innes (Merton Park) and Mitcham Cricket Green remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Merton is determined against an 8-week statutory target.
Wimbledon (the leafy Village above Edwardian and Victorian streets), Merton Park (the John Innes estate of Arts and Crafts and Edwardian houses), Mitcham (interwar housing wrapped around the historic cricket green), Raynes Park (grids of Edwardian terraces west of the line), Colliers Wood (compact Victorian terraces along the Wandle) and Morden (1930s semi-detached suburbia and the St Helier fringe) — these are the Merton pockets our drawings cover most. Heritage designations here include Wimbledon Village, John Innes (Merton Park), Mitcham Cricket Green, Cottenham Park and Wimbledon West. Merton Council weighs each proposal against Merton Local Plan and the council's Design SPD, where the John Innes estate's Arts and Crafts detailing is protected in fine grain, down to porches, gates and boundary walls. Pockets of Wimbledon and Colliers Wood hold converted Victorian flats and maisonettes, which carry no householder permitted-development rights of their own.. On roofs the borough is pitched and gabled roofs on the terraces and villas and hipped roofs on the interwar semis, over Victorian and Edwardian terraces, detached Wimbledon villas and interwar semi-detached houses.
Merton homes come in a handful of recurring shapes, and each one points to a different extension. The borough is built largely from Victorian and Edwardian terraces, detached Wimbledon villas and interwar semi-detached houses, so a Victorian terrace usually wants a rear or side-return infill, while an interwar semi has room for a wider single-storey wrap or a two-storey side addition. Merton Council judges every one of them against Merton Local Plan and the council's Design SPD, weighing footprint, height and the impact on the house next door before it looks at the elevations.
That is why the drawings decide the outcome. We set the extension depth against the permitted-development limits precisely, keep the eaves and ridge within the allowances, and plot the 45-degree daylight lines to the neighbours' windows so the case officer can see the amenity test is passed. The wooded, low-density character of Wimbledon Village and the Common caps bulk and roof enlargement on many plots, so we design around it from the first sketch rather than discover it at validation.
Merton also protects whole streets — Wimbledon Village, John Innes (Merton Park), Mitcham Cricket Green, Cottenham Park and Wimbledon West among them. Merton has withdrawn permitted-development rights on parts of the John Innes and Wimbledon Village conservation areas through Article 4 directions, so alterations that would be automatic elsewhere need a householder application here. On designated land the larger-home extension route and most side extensions stop being permitted development, so we confirm your address against those layers before drawing a line.
Plenty of Merton extensions are permitted development and need no planning application — a single-storey rear extension within the depth and height limits is the common case. You will normally need to apply to Merton Council if any of these apply:
We draw the footprint, the ridge and eaves heights and the neighbours' daylight on the page — the relationships Merton Council's officers weigh first — and submit a validation-complete pack, whether that is a lawful development certificate, a prior-approval notification or a full householder application.
Below is Merton Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Merton consents the large majority of householder schemes, yet the leafy Wimbledon conservation areas and the uniform villa streets set close limits on how far roofs and side additions can go. A complete, policy-literate extension pack anticipates those pressure points before submission, which is why professionally drawn applications are decided faster and refused less often than DIY ones.
Source: MHCLG planning application statistics (householder decisions, rolling year). Compare every borough on our London approval-rate league table.
Tell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Across Wimbledon, Merton Park and Mitcham, the extension that lands most often is the single-storey rear addition — a glazed kitchen-diner across the back of the house, kept within the permitted-development depth or taken to a full application where the ground floor wants more. On the borough's victorian and edwardian terraces, a side-return infill frequently pairs with it to square off the plan; on wider interwar semi-detached houses, a two-storey side or rear extension can add a bedroom above without swallowing the garden.
The John Innes estate's Arts and Crafts detailing is protected in fine grain, down to porches, gates and boundary walls. We size the extension to the amenity and daylight tests, match the roof and materials to the host house, and keep enough garden to satisfy Merton Council's space standards — so the scheme answers the borough's questions before an objection can raise them. Where permitted-development rights are used up or removed, we prepare the householder application to the council's extension design guidance instead.
We draw extensions on every street in the borough. A few of the neighbourhoods where Merton projects come up most often:
Extension drawings for Wimbledon's the leafy Village above Edwardian and Victorian streets — footprint-checked, daylight-tested and drawn to Merton Council's guidance.
Extension drawings for Merton Park's the John Innes estate of Arts and Crafts and Edwardian houses — footprint-checked, daylight-tested and drawn to Merton Council's guidance.
Extension drawings for Mitcham's interwar housing wrapped around the historic cricket green — footprint-checked, daylight-tested and drawn to Merton Council's guidance.
Extension drawings for Raynes Park's grids of Edwardian terraces west of the line — footprint-checked, daylight-tested and drawn to Merton Council's guidance.
Extension drawings for Colliers Wood's compact Victorian terraces along the Wandle — footprint-checked, daylight-tested and drawn to Merton Council's guidance.
Extension drawings for Morden's 1930s semi-detached suburbia and the St Helier fringe — footprint-checked, daylight-tested and drawn to Merton Council's guidance.
The right extension in Merton depends on your house type and how much garden you can give up. This is how the main options compare on planning route and what they add.
| Extension type | Permitted development? | What it adds | What Merton Council checks |
|---|---|---|---|
| Single-storey rear | Often, within 3m/4m depth (6m/8m via prior approval) | Bigger kitchen-diner across the back | Depth, height, neighbour daylight (45°) |
| Side-return infill | Sometimes, if within width and height limits | Squares off an L-shaped ground floor | Width vs the original house, glazing to boundary |
| Two-storey rear/side | No — full application | Extra bedroom or bathroom above | Bulk, overlooking, 7m rear-boundary gap |
| Wraparound (rear + side) | No — full application | Whole-width open-plan ground floor | Combined footprint and garden retained |
Route depends on your street — conservation areas such as Wimbledon Village and John Innes (Merton Park) and Article 4 directions can remove permitted-development rights.
A fixed process built around how Merton Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.
Tell us your Merton postcode and house type. We confirm your conservation and Article 4 status, how much permitted-development depth you have left, and score your odds against live Merton Council decisions.
We measure the existing footprint, floor and eaves levels, boundary distances and the neighbours' window positions — the numbers the depth limits and daylight tests depend on.
Chartered designers develop the single-storey, two-storey or side extension to your brief, drawn inside the permitted-development limits or to Merton Council's extension design guidance.
We submit the certificate, prior-approval notice or application, manage validation and case-officer queries, and revise the drawings free until Merton Council issues its decision.
Not always. A single-storey rear extension up to 3 metres deep on a terrace or semi, or 4 metres on a detached house, and no higher than 4 metres, is usually permitted development. In Merton you will need to apply to Merton Council for two-storey extensions, side extensions wider than half the house, anything forward of the front wall, deeper rear extensions under the larger-home prior-approval route, and any extension in a conservation area such as Wimbledon Village and John Innes (Merton Park).
Standard permitted development allows 3 metres on a terraced or semi-detached house and 4 metres on a detached one. The larger-home extension scheme can double that to 6 or 8 metres, but it needs a prior-approval notification to Merton Council and a neighbour-consultation period, and it does not apply on designated land such as Merton's conservation areas. We confirm which route your property qualifies for before drawing.
Two-storey and double-storey extensions almost always need a full householder application to Merton Council, because they fall outside permitted development on most homes. The council looks closely at bulk, overlooking of neighbours and the 7-metre gap a two-storey rear extension must keep from the rear boundary. We design to those tests and show the daylight and privacy angles on the drawings.
A householder planning application in Merton runs to a statutory eight-week target, a larger-home prior-approval notification to around six weeks including the neighbour-consultation period, and a lawful development certificate to eight weeks. Incomplete submissions stall at validation, so we submit a complete pack and manage officer queries to keep the decision on schedule. Merton Council is the decision-maker.
Yes — planning permission and building regulations are separate consents, and almost every extension needs both. Planning governs whether you can build it; building control governs how it is built, covering structure, insulation, drainage and fire safety. We prepare the building-regulations drawings alongside the planning set so Merton Council's building control or an approved inspector can sign the work off.
Every house and brief is different, so we price each Merton extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Merton Council approves, and we tell you upfront whether your extension qualifies as permitted development. Call 020 7864 7245 to get started.
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Same fixed quotes, same fast drawings — wherever your project is.