Two-storey extension drawings for Merton homes — bedroom above, living space below, drawn against the 3-metre projection and 7-metre boundary rules and to Merton Council's design guidance, delivered in days and revised free until your decision.
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.
Adding at first floor changes the question the case officer asks. A single-storey extension is judged mostly on daylight and garden loss; a two-storey extension is judged on overlooking, bulk against the neighbouring roofline, and whether it reads as part of the house or bolted onto it. Merton is largely Victorian and Edwardian terraces, detached Wimbledon villas and interwar semi-detached houses, and pitched and gabled roofs on the terraces and villas and hipped roofs on the interwar semis set what a matching roof actually means here.
The permitted-development route exists but is narrow: 3 metres of rear projection, a 7-metre stand-off from the rear boundary, eaves and ridge no higher than the original, and side-facing upper windows obscure-glazed and non-opening below 1.7 metres above floor level. Most two-storey schemes fail one of those, usually the 7-metre boundary rule on a shorter garden, and go in as a full application instead. We establish which route applies before designing, because it changes the drawing set.
The wooded, low-density character of Wimbledon Village and the Common caps bulk and roof enlargement on many plots. 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.
Some two-storey rear extensions are permitted development. You will need a full application to Merton Council if any of these apply:
We set the projection and boundary distance on the site plan, prove the roof-pitch match on the elevations, and specify obscure glazing on the side windows — the three things Merton Council checks first — then submit a validation-complete pack.
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. Two-storey schemes attract more neighbour comment than any other householder work, so the overlooking and daylight case has to be made on the drawings.
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 schemes that succeed set the first floor back from the ground floor, keep the ridge below the original, and treat the flank wall as blank or obscure-glazed. On victorian and edwardian terraces, matching the eaves line matters more than matching the brick: an extension that carries the existing eaves through reads as original even in a different material.
The John Innes estate's Arts and Crafts detailing is protected in fine grain, down to porches, gates and boundary walls. We draw the 45-degree daylight test from the neighbour's nearest habitable window, show the window positions in section, and set out the steel and foundation implications early — a two-storey extension changes the load path, so the structural design and the planning design have to be developed together rather than in sequence.
We draw two-storey extensions across Merton. A few of the areas where they come up most often:
Two storey extension drawings for Wimbledon — the leafy Village above Edwardian and Victorian streets — dimensioned against the 3m and 7m limits and drawn to Merton Council's guidance.
Two storey extension drawings for Merton Park — the John Innes estate of Arts and Crafts and Edwardian houses — dimensioned against the 3m and 7m limits and drawn to Merton Council's guidance.
Two storey extension drawings for Mitcham — interwar housing wrapped around the historic cricket green — dimensioned against the 3m and 7m limits and drawn to Merton Council's guidance.
Two storey extension drawings for Raynes Park — grids of Edwardian terraces west of the line — dimensioned against the 3m and 7m limits and drawn to Merton Council's guidance.
Two storey extension drawings for Colliers Wood — compact Victorian terraces along the Wandle — dimensioned against the 3m and 7m limits and drawn to Merton Council's guidance.
Two storey extension drawings for Morden — 1930s semi-detached suburbia and the St Helier fringe — dimensioned against the 3m and 7m limits and drawn to Merton Council's guidance.
The first-floor limits are tighter than the ground-floor ones. This is how the common cases compare.
| Scheme | Permitted development? | Deciding limit | What Merton Council checks |
|---|---|---|---|
| Two-storey rear, 3m projection, 7m+ to boundary | Often yes | 3m projection / 7m boundary | Roof match, side-window glazing |
| Two-storey rear, under 7m to boundary | No — full application | Rear-boundary distance | Overlooking, daylight, garden loss |
| Two-storey side extension | No — full application | Side elevation | Gap to boundary, street rhythm |
| Two-storey wraparound | No — full application | Combined footprint | Bulk, massing, neighbour amenity |
| Any two-storey on designated land | No — full application | Designation | Character and appearance |
Limits from the GPDO 2015, Schedule 2, Part 1, Class A — two-storey rear extension conditions.
A fixed process built around how Merton Council validates and decides two-storey applications.
Send us your Merton postcode and garden depth. We measure the 7-metre boundary rule against your plot, confirm designation status, and score your odds against live Merton Council decisions.
We measure the original rear wall, eaves and ridge heights, garden depth and every neighbouring window that faces the site — the inputs the daylight and overlooking case is built from.
Chartered designers develop the two-storey addition to your brief with the roof and eaves resolved, and we coordinate the load path so the structural scheme and the planning scheme are the same building.
We submit the application, manage validation and case-officer queries, and revise the drawings free until Merton Council issues its decision.
Often, but not always. A two-storey rear extension can be permitted development if it projects no more than 3 metres, sits at least 7 metres from the rear boundary, does not exceed the existing eaves and ridge, and has obscure-glazed non-opening side windows below 1.7 metres. In Merton, the 7-metre rule is what most commonly forces a full application to Merton Council.
No part of a permitted-development two-storey rear extension may come within 7 metres of the boundary opposite the rear wall of the house. It exists to protect the neighbour behind you from being overlooked at first floor. On shorter Merton gardens this is decisive, and we measure it on survey before any design work rather than discovering it at validation. Merton Council is the decision-maker.
Not under permitted development — two-storey side extensions always need a full application to Merton Council. They are assessed on the gap to the boundary, whether the street's rhythm of spaces between houses survives, and whether the extension is subordinate to the original. Setting the first floor back from the front building line and down from the ridge is what usually makes the difference.
Overlooking is the most common objection, and it is answerable on the drawings. We position habitable-room windows away from neighbouring gardens, obscure-glaze and fix shut anything on the flank below 1.7 metres, and show the sight lines in section. Where the geometry is tight, a rooflight or a high-level window gives the same daylight without the mutual overlooking that draws objections. This applies to your Merton address specifically. Merton Council is the decision-maker.
Almost certainly. Excavating within 3 metres of a neighbouring structure and building on or up to the boundary both trigger the Party Wall etc. Act 1996, and a two-storey extension usually does both. It is entirely separate from Merton Council's planning decision, so we flag the notice period early and detail the junction on the drawings.
Yes. Adding a floor changes the load path from roof to foundation, so beams, padstones and foundation depths all need designing and calculating for building control. Planning and building regulations are separate consents, and the structural set is what building control assesses — we prepare both so the approved scheme is the buildable one. This applies to your Merton address specifically. Merton Council is the decision-maker.
We quote each Merton two-storey extension individually, because plot depth, roof form and structural complexity vary house to house, and send a fixed, no-obligation quote within one working day. It covers the drawing pack with free revisions until Merton Council approves. Call 020 7864 7245 to start.
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