Mansard drawings for Lewisham terraces — the rebuilt roof with a steep, near-vertical rear slope that adds a full storey of loft, drawn to Lewisham Council's roofline and streetscape rules, delivered in days and revised free until your decision, with a free approval-odds check first.
Lewisham Council granted 90% of the householder planning decisions it made in its latest published year — 3 points above the 87% England-wide householder average. Policies resist the loss of family-sized houses, so conversions to flats face an added hurdle, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837), Victorian (1837–1901) and Edwardian (1901–1910) housing stock sets the design brief on most streets.
Under Class B, a rear dormer stays permitted development up to 40m³ of added roof volume on a terrace or 50m³ on a semi-detached or detached house, while Class A allows a single-storey rear extension of 3m beyond the original rear wall on a terrace and 4m on a detached house before a full application is needed. Lewisham carries at least one Article 4 direction, and conservation areas including Blackheath, Telegraph Hill and Brockley remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Lewisham is determined against an 8-week statutory target.
Blackheath (grand villas and terraces on the Lewisham side of the heath), Brockley (long Victorian terraces within one of London's largest conservation areas), Telegraph Hill (hilly Victorian terraces framing the two parks), Deptford (Georgian survivals like Albury Street amid dense terraced streets), Forest Hill (Victorian villas and terraces stepping up the slopes) and Sydenham (Victorian terraces and semis toward the Crystal Palace ridge) — these are the Lewisham pockets our drawings cover most. Heritage designations here include Blackheath, Telegraph Hill, Brockley, Deptford High Street and Sydenham. Lewisham Council weighs each proposal against the Lewisham Local Plan and the borough's Alterations and Extensions SPD, where in the Brockley and Telegraph Hill conservation areas original slate roofs and front elevations are closely guarded. Brockley, Forest Hill and Deptford hold large numbers of houses long ago converted into flats and maisonettes, which carry no householder permitted-development rights.. On roofs the borough is London butterfly roofs on the Victorian terraces and gabled roofs on the villas, over Victorian terraces, Victorian and Edwardian villas and converted flats and maisonettes.
The mansard is the maximum-volume loft, and Lewisham's stock is where it belongs — the borough runs to Victorian terraces, Victorian and Edwardian villas and converted flats and maisonettes, 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. Lewisham Council assesses it against the Lewisham Local Plan and the borough's Alterations and Extensions SPD, 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. Policies resist the loss of family-sized houses, so conversions to flats face an added hurdle, and on a roof this prominent that is the argument that has to be won on the page.
Much of Lewisham's terraced stock is designated — Blackheath, Telegraph Hill, Brockley, Deptford High Street and Sydenham among the areas — and there a mansard is judged on whether it restores or respects the historic roofline. Lewisham operates Article 4 directions in conservation areas such as Brockley alongside controls resisting the conversion of family houses into flats, so works that are permitted development elsewhere routinely need an application here. Some terraces already have a consistent mansard line an addition can follow; others do not, and we establish which before drawing.
A mansard in Lewisham always needs a full application to Lewisham 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 Lewisham Council's officers check first — and submit a validation-complete householder application.
Below is Lewisham Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Lewisham grants the large majority of householder applications, though its policy shielding family houses from conversion and its Victorian conservation areas shape roof and rear works street by street. 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 Blackheath, Brockley and Telegraph Hill, 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.
In the Brockley and Telegraph Hill conservation areas original slate roofs and front elevations are closely guarded. 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 Lewisham 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 Lewisham mansards come up most often:
Mansard loft drawings for Blackheath's grand villas and terraces on the Lewisham side of the heath — roofline-matched, slate-detailed and drawn to Lewisham Council's guidance.
Mansard loft drawings for Brockley's long Victorian terraces within one of London's largest conservation areas — roofline-matched, slate-detailed and drawn to Lewisham Council's guidance.
Mansard loft drawings for Telegraph Hill's hilly Victorian terraces framing the two parks — roofline-matched, slate-detailed and drawn to Lewisham Council's guidance.
Mansard loft drawings for Deptford's Georgian survivals like Albury Street amid dense terraced streets — roofline-matched, slate-detailed and drawn to Lewisham Council's guidance.
Mansard loft drawings for Forest Hill's Victorian villas and terraces stepping up the slopes — roofline-matched, slate-detailed and drawn to Lewisham Council's guidance.
Mansard loft drawings for Sydenham's Victorian terraces and semis toward the Crystal Palace ridge — roofline-matched, slate-detailed and drawn to Lewisham 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 Lewisham.
| Loft type | Planning route | Space gained | What Lewisham 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 Blackheath and Telegraph Hill, a mansard is judged on how it sits within the protected roofline of the terrace.
A fixed process built around how Lewisham Council validates and decides mansard applications — most drawings are submission-ready within seven days of survey.
Send us your Lewisham 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 Lewisham 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 Lewisham 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 Lewisham 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 Lewisham Council on every street, designated or not. On a terrace in a conservation area such as Blackheath and Telegraph Hill 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. Lewisham'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. Lewisham 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 Lewisham, a mansard is chosen when a dormer or hip-to-gable will not give enough room. Lewisham 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, Lewisham 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 Lewisham 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 Lewisham 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 Lewisham Council approves, and we confirm the roofline case at the outset. Call 020 7864 7245 to start.
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