Mansard drawings for Wandsworth terraces — the rebuilt roof with a steep, near-vertical rear slope that adds a full storey of loft, drawn to Wandsworth Council's roofline and streetscape rules, 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 mansard is the maximum-volume loft, and Wandsworth's stock is where it belongs — the borough runs to Victorian terraces, Edwardian mansion flats and Putney and Wandsworth villas, and on a period terrace a mansard rebuilds the roof at roughly seventy degrees to create almost a full new floor rather than the part-height room a dormer returns. Wandsworth Council assesses it against Wandsworth Local Plan and the borough's Housing and Basements SPDs, and because the whole roof changes shape the test is the street: whether the new profile continues the terrace or breaks it.
That is what the drawings have to settle. We set the mansard behind the original parapet or eaves, hold it to the ridge height of neighbouring mansards where the terrace already has them, and detail the slate face, the dormer windows within it and the party walls to both sides so the addition reads as part of the row. Side returns, mansards and dormers are judged in centimetres against the party wall and shared roofline, and on a roof this prominent that is the argument that has to be won on the page.
Much of Wandsworth's terraced stock is designated — Wandsworth Common, Nightingale Triangle, Tonsleys, Magdalen Park and Battersea Park among the areas — and there a mansard is judged on whether it restores or respects the historic roofline. 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. Some terraces already have a consistent mansard line an addition can follow; others do not, and we establish which before drawing.
A mansard in Wandsworth always needs a full application to Wandsworth Council — rebuilding the roof puts it well outside permitted development. These are the points the council weighs:
We draw the new roof behind the parapet, the slope and ridge matched to the terrace, the slate face and dormer windows, and the party walls to both neighbours — the roofline and streetscape relationships Wandsworth Council's officers check first — and submit a validation-complete 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 mansard is decided on roofline and streetscape, so a scheme drawn to continue the terrace is cleared faster and refused less often than one that fights it.
Source: MHCLG planning application statistics (householder decisions, rolling year). Compare every borough on our London approval-rate league table.
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Across Battersea, Balham and Tooting, the mansard that goes through is the one that disappears into the row: set behind the parapet, its ridge matched to neighbouring mansards, the front slope in natural slate with traditional dormer windows, and the whole storey reading as though the terrace was always that height. On the borough's victorian terraces, this is the single biggest volume the roof can give — close to a full floor.
The borough applies detailed basement-development policies on top of the usual tests. We follow any established mansard line on the terrace, keep the slope and materials traditional, and where a row has none yet, draw a design that could set the pattern rather than break it — the argument Wandsworth Council needs to grant on a roof this visible.
We draw mansard roofs on the period-terrace streets across the borough. A few of the neighbourhoods where Wandsworth mansards come up most often:
Mansard loft drawings for Battersea's Victorian terraces and mansion flats near the park — roofline-matched, slate-detailed and drawn to Wandsworth Council's guidance.
Mansard loft drawings for Balham's Edwardian terraces around the Nightingale Triangle — roofline-matched, slate-detailed and drawn to Wandsworth Council's guidance.
Mansard loft drawings for Tooting's long Victorian terraces off the high road — roofline-matched, slate-detailed and drawn to Wandsworth Council's guidance.
Mansard loft drawings for Putney's Edwardian villas and riverside streets — roofline-matched, slate-detailed and drawn to Wandsworth Council's guidance.
Mansard loft drawings for Earlsfield's compact Victorian terraces between the commons — roofline-matched, slate-detailed and drawn to Wandsworth Council's guidance.
Mansard loft drawings for Southfields's the Magdalen Park grid of Edwardian houses — roofline-matched, slate-detailed and drawn to Wandsworth Council's guidance.
A mansard wins the most space of any loft but asks the most of the planning case. This is how it compares in Wandsworth.
| Loft type | Planning route | Space gained | What Wandsworth Council checks |
|---|---|---|---|
| Mansard | Always a full application | Close to a full extra storey | Roofline, streetscape, terrace match |
| Rear dormer | Often permitted development | A room across the back slope | Volume and eaves set-back |
| Hip-to-gable | Full application | Full width where the roof is hipped | Balance with the paired neighbour |
| Rooflights only | Usually permitted development | Light and headroom, no new shape | Rooflights within the existing slope |
In conservation areas such as Wandsworth Common and Nightingale Triangle, a mansard is judged on how it sits within the protected roofline of the terrace.
A fixed process built around how Wandsworth Council validates and decides mansard applications — most drawings are submission-ready within seven days of survey.
Send us your Wandsworth postcode and terrace type. We confirm your conservation and Article 4 status, check whether the row already has a mansard line to follow, and score your odds against live Wandsworth Council decisions.
We measure the parapet, ridge and party walls, and the roofline of the neighbouring houses — the numbers the new slope, its height and the terrace match depend on.
Chartered designers develop the rebuilt roof to your brief, drawn to Wandsworth Council's roof-alteration and conservation guidance with the slope, slate face, dormers and party walls detailed on the page.
We submit the householder application, manage validation and case-officer queries, and revise the drawings free until Wandsworth Council issues its decision.
Always. A mansard rebuilds the roof into a steep rear slope with a flat top, and that wholesale change of roof shape is well outside permitted development — so it needs a full householder application to Wandsworth Council on every street, designated or not. On a terrace in a conservation area such as Wandsworth Common and Nightingale Triangle the roofline is protected, so the design is scrutinised more closely still.
It is a rebuilt roof with a steep, near-vertical rear slope and a small flat top, which creates almost a full extra storey inside — far more than a dormer returns. Wandsworth's period terraces are the classic mansard candidates, and where a row already carries mansards a new one that matches the line is the most likely of all lofts to be approved despite being the largest. Wandsworth Council is the decision-maker.
Because it reshapes the whole roof rather than adding a box to it. The steep slope pushes the walls out almost to vertical and the flat top lifts the ceiling, so the usable floor runs nearly the full footprint of the house at head height — close to a complete storey. That is why, in Wandsworth, a mansard is chosen when a dormer or hip-to-gable will not give enough room. Wandsworth Council is the decision-maker.
It can, but the case is harder. Where a terrace already has a consistent mansard line, matching it is straightforward; on an unbroken row, Wandsworth Council weighs whether your mansard would break the skyline or could set an acceptable pattern for the street. We draw the design to sit within the terrace and make that argument on the elevations rather than leave it to chance.
Almost certainly, on both sides. A mansard rebuilds the roof up to and across the party walls with the neighbours either side, so the Party Wall etc. Act applies to each and notice must be served before work starts — separately from Wandsworth Council's planning decision. We detail both party walls on the drawings and flag the notices early so surveyors can be appointed without holding up the build.
We price each Wandsworth mansard individually, because the terrace, the roofline match and the party-wall detailing vary street to street, 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 the roofline case at the outset. Call 020 7864 7245 to start.
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