Rear dormer drawings for Wandsworth roofs — the box across the back slope that turns a low attic into a full-height room, drawn to Wandsworth Council's guidance and the volume limits, delivered in days and revised free until your decision, with a free approval-odds check first.
Wandsworth Council granted 88% of the householder planning decisions it made in its latest published year — 1 point above the 87% England-wide householder average. Side returns, mansards and dormers are judged in centimetres against the party wall and shared roofline, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901) and Edwardian (1901–1910) housing stock sets the design brief on most streets.
Before permission is required, Class B allows 40m³ of added loft volume on a terrace and 50m³ on a semi or detached house, and Class A allows a 3m single-storey rear extension on a terrace or 4m on a detached house. Wandsworth carries at least one Article 4 direction, and conservation areas including Wandsworth Common, Nightingale Triangle and Tonsleys remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Wandsworth is determined against an 8-week statutory target.
Battersea (Victorian terraces and mansion flats near the park), Balham (Edwardian terraces around the Nightingale Triangle), Tooting (long Victorian terraces off the high road), Putney (Edwardian villas and riverside streets), Earlsfield (compact Victorian terraces between the commons) and Southfields (the Magdalen Park grid of Edwardian houses) — these are the Wandsworth pockets our drawings cover most. Heritage designations here include Wandsworth Common, Nightingale Triangle, Tonsleys, Magdalen Park and Battersea Park. Wandsworth Council weighs each proposal against Wandsworth Local Plan and the borough's Housing and Basements SPDs, where the borough applies detailed basement-development policies on top of the usual tests. Much of Battersea and Balham is converted flats and maisonettes, which carry no householder permitted-development rights.. On roofs the borough is butterfly / valley roofs on the terraces and pitched roofs on the villas, over Victorian terraces, Edwardian mansion flats and Putney and Wandsworth villas.
The box dormer is the workhorse loft, and most of Wandsworth is built for it — the borough runs to Victorian terraces, Edwardian mansion flats and Putney and Wandsworth villas under butterfly / valley roofs on the terraces and pitched roofs on the villas, and a flat-roofed box across the rear slope is the cheapest cubic metre of full-height space those roofs give up. Wandsworth Council tests the dormer against Wandsworth Local Plan and the borough's Housing and Basements SPDs, and because permitted development turns on a number, the volume you propose against the volume you have left is the first thing an officer or a certificate checks.
That is why the arithmetic goes on the drawings. We calculate the box against the 40- or 50-cubic-metre allowance, count any earlier roof enlargement into the total, hold the flat roof below the ridge and set the face back off the eaves so the dormer reads as subordinate. Side returns, mansards and dormers are judged in centimetres against the party wall and shared roofline, so the cheeks, the window line and the material are drawn to answer it rather than invite a query.
Where Wandsworth's streets are protected — Wandsworth Common, Nightingale Triangle, Tonsleys, Magdalen Park and Battersea Park among them — the Class B dormer right is switched off and even a modest rear box needs consent. Several Wandsworth conservation areas carry Article 4 directions, and the borough's dense conservation coverage means many terraced streets need a full application for works that would be PD elsewhere. We confirm the designation before the box is sized.
Many rear dormers in Wandsworth are permitted development, but the volume and position decide it. You will normally need a full application to Wandsworth Council if any of these apply:
We draw the box within its volume allowance, the flat roof below the ridge and the face set back off the eaves — the three things a dormer stands or falls on — and submit a validation-complete pack, whether that is a lawful development certificate or a full householder application.
Below is Wandsworth Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Wandsworth grants a healthy share of householder applications, but its uniform Victorian terraces mean side returns and roof alterations are assessed in centimetres against the neighbours. A dormer is decided on volume and set-back, so a pack that shows the calculation and the eaves detail is cleared faster and refused less often than a DIY submission.
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 Battersea, Balham and Tooting, the dormer that goes through is the subordinate rear box: flat roof kept low, cheeks clad to recede, side windows obscure-glazed against overlooking, and the whole thing set back so the original eaves line still reads from the garden. On butterfly / valley roofs on the terraces, this returns a full-height double and en-suite from what was standing-room-only, usually inside the permitted-development volume.
The borough applies detailed basement-development policies on top of the usual tests. We keep the box off the ridge, match the cheek material to the roof, and where the volume is already spent — or the street is designated — draw the dormer as a householder application composed to Wandsworth Council's roof-alteration guidance rather than push a certificate that would be refused.
We draw rear dormers on the terraced and semi-detached streets across the borough. A few of the neighbourhoods where Wandsworth dormers come up most often:
Dormer loft drawings for Battersea's Victorian terraces and mansion flats near the park — volume-checked, set-back-detailed and drawn to Wandsworth Council's guidance.
Dormer loft drawings for Balham's Edwardian terraces around the Nightingale Triangle — volume-checked, set-back-detailed and drawn to Wandsworth Council's guidance.
Dormer loft drawings for Tooting's long Victorian terraces off the high road — volume-checked, set-back-detailed and drawn to Wandsworth Council's guidance.
Dormer loft drawings for Putney's Edwardian villas and riverside streets — volume-checked, set-back-detailed and drawn to Wandsworth Council's guidance.
Dormer loft drawings for Earlsfield's compact Victorian terraces between the commons — volume-checked, set-back-detailed and drawn to Wandsworth Council's guidance.
Dormer loft drawings for Southfields's the Magdalen Park grid of Edwardian houses — volume-checked, set-back-detailed and drawn to Wandsworth Council's guidance.
Whether a dormer in Wandsworth needs permission comes down to where it sits and how big the box is. This is how the cases compare.
| Dormer type | Permitted development? | What it gains | What Wandsworth Council checks |
|---|---|---|---|
| Rear box, within volume | Usually yes | Full-height room across the back | Volume total, 20cm eaves set-back |
| Rear box, over volume limit | No — full application | A larger room | How far over the allowance, bulk |
| Front or side dormer | No — full application | Light to the front rooms | Visibility from the street, character |
| Dormer in a conservation area | No — full application | Same space, extra scrutiny | Roof form and street appearance |
In conservation areas such as Wandsworth Common and Nightingale Triangle, Class B dormer rights are removed and every dormer needs a full application.
A fixed process built around how Wandsworth Council validates and decides dormer applications — most drawings are submission-ready within seven days of survey.
Send us your Wandsworth postcode and roof type. We confirm your conservation and Article 4 status, work out how much permitted-development volume you have left, and score your odds against live Wandsworth Council decisions.
We measure ridge and eaves heights, roof pitch and the existing loft floor — the numbers the volume calculation, the set-back and the head heights depend on.
Chartered designers develop the box to your brief, drawn inside the Class B volume limits or, where those are exhausted or removed, to Wandsworth Council's roof-alteration guidance.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until Wandsworth Council issues its decision.
Often not. A rear box dormer within 40 cubic metres on a terrace, or 50 on a semi or detached house, set back at least 20 centimetres from the eaves and kept below the ridge, is usually permitted development. In Wandsworth you will need a full application to Wandsworth Council for a front or side dormer, a box that exceeds the volume, and any dormer in a conservation area such as Wandsworth Common and Nightingale Triangle, where those rights are removed.
The permitted-development limit is a volume, not a footprint: 40 cubic metres of added roof space on a terraced house and 50 on a semi-detached or detached one, and any earlier loft enlargement counts against that total. In Wandsworth the box must also sit below the ridge and back from the eaves. We measure your roof and calculate the exact volume you have left before drawing. Wandsworth Council is the decision-maker.
Not under permitted development. A dormer on the front roof slope, or one facing a highway, always needs a full application to Wandsworth Council, because it changes how the house reads from the street. Rear box dormers are far more likely to be approved — or to be permitted development outright — which is why almost every Wandsworth dormer we draw sits on the back slope.
Often, on a terrace or semi. If the dormer or the loft steelwork meets the party wall with your neighbour, the Party Wall etc. Act applies and notice must be served before work starts — separately from Wandsworth Council's planning decision. We flag the party-wall junction on the drawings so a surveyor can be appointed early and the build is not held up.
If your dormer is permitted development, a lawful development certificate from Wandsworth Council is council-stamped proof of it — worth holding, because a buyer's solicitor will ask for it when you sell. We prepare and submit the certificate with the same measured drawing pack that shows the box within its volume allowance.
We price each Wandsworth dormer individually, because the roof pitch and the volume left vary house to house, and send a fixed, no-obligation quote within one working day. It covers the full drawing pack with free revisions until Wandsworth Council approves, and we confirm at the outset whether your box is permitted development or needs an application. Call 020 7864 7245 to start.
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