Dormer, hip-to-gable and mansard loft conversion drawings for Lambeth homes — prepared to Lambeth Council's design guidance, delivered in days and revised free until your decision lands, with a free approval-odds score first.
Lambeth Council granted 89% of the householder planning decisions it made in its latest published year — 2 points above the 87% England-wide householder average. The loss of family houses to further flat conversion is resisted and frequently the deciding issue, 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.
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. Lambeth carries at least one Article 4 direction, and conservation areas including Clapham Old Town, Stockwell Park and Angell Town remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Lambeth is determined against an 8-week statutory target.
Clapham (Georgian and Victorian terraces around the Old Town and Common), Brixton (Victorian terraces heavily subdivided into flats), Stockwell (Georgian and Victorian streets around Stockwell Park), Herne Hill (Victorian villas and terraces on the Dulwich fringe), Streatham (Edwardian terraces and mansion blocks along the high road) and Kennington (Georgian and Regency terraces near the river) — these are the Lambeth pockets our drawings cover most. Heritage designations here include Clapham Old Town, Stockwell Park, Angell Town, Herne Hill and Leigham Court Estate. Lambeth Council weighs each proposal against Lambeth Local Plan and the council's Alterations and Extensions SPD, where mansards and roof additions on stucco-fronted terraces are measured against whatever original roofline survives on the street. Much of Brixton, Clapham and Stockwell is already converted flats and maisonettes, which hold no householder permitted-development rights.. On roofs the borough is butterfly and valley roofs behind the terrace parapets and mansard and pitched roofs on the taller stucco streets, over Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and estates.
Lambeth's roofs set the brief. The borough is built largely from Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and estates, and its lofts sit under butterfly and valley roofs behind the terrace parapets and mansard and pitched roofs on the taller stucco streets — the geometry that decides whether a rear dormer, a hip-to-gable or a mansard gives you the headroom you want. Lambeth Council assesses loft proposals against Lambeth Local Plan and the council's Alterations and Extensions SPD, and its case officers read each roof against the pair next door and the wider street before they read the plans.
That makes drawing quality decisive. We measure ridge and eaves heights, roof pitch and the existing stair, calculate the added volume against the permitted-development limits exactly, and show the workings on the drawings so Lambeth Council can verify them. The loss of family houses to further flat conversion is resisted and frequently the deciding issue, so we resolve it on the page rather than leave it for the case officer to raise.
Lambeth also carries protected streets — Clapham Old Town, Stockwell Park, Angell Town, Herne Hill and Leigham Court Estate among them. Alongside the controls in conservation areas such as Clapham Old Town, Lambeth runs a borough-wide Article 4 direction removing permitted-development rights for small shared houses, pulling many HMO changes into the application system. We check your address against those designations before a line is drawn.
Many Lambeth loft conversions proceed without planning permission — a rear dormer within the permitted-development volume limits (40 cubic metres on a terrace, 50 on a semi or detached house) is usually lawful. You will normally need a full application to Lambeth Council if any of these apply:
We draw the roof line, the ridge height and the neighbour's daylight on the page — the relationships Lambeth Council's officers check first — and submit a validation-complete pack, whether that is a lawful development certificate or a full householder application.
Below is Lambeth Council's real householder decision record, pulled from official planning statistics and updated as new data lands. Lambeth grants a high proportion of householder applications, but with so much of its stock already split into flats, protecting the remaining family houses is what shapes most refusals. Professionally prepared loft drawings anticipate those pressure points before submission, which is why complete, policy-literate packs are decided faster and refused less often than DIY applications.
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 Clapham, Brixton and Stockwell, the recurring loft is the rear dormer — a box across the back roof slope that turns a cramped attic into a full-height double bedroom and en-suite. On butterfly and valley roofs behind the terrace parapets, that is usually the most efficient use of the roof; where the stock is mansard and pitched roofs on the taller stucco streets, a hip-to-gable followed by a rear dormer unlocks far more space, though it needs a full application.
Mansards and roof additions on stucco-fronted terraces are measured against whatever original roofline survives on the street. We draw the dormer inside the volume allowance, keep the flat-roof build-up below the ridge, and set the face back from the eaves as the rules require — so the pack answers Lambeth Council's questions before they are asked. Where permitted-development rights are exhausted or removed, we prepare a householder application composed to the borough's roof-alteration guidance instead.
We draw loft conversions on every street in the borough. A few of the neighbourhoods where Lambeth roofs come up most often:
Loft conversion drawings for Clapham's Georgian and Victorian terraces around the Old Town and Common — measured, volume-checked and drawn to Lambeth Council's guidance.
Loft conversion drawings for Brixton's Victorian terraces heavily subdivided into flats — measured, volume-checked and drawn to Lambeth Council's guidance.
Loft conversion drawings for Stockwell's Georgian and Victorian streets around Stockwell Park — measured, volume-checked and drawn to Lambeth Council's guidance.
Loft conversion drawings for Herne Hill's Victorian villas and terraces on the Dulwich fringe — measured, volume-checked and drawn to Lambeth Council's guidance.
Loft conversion drawings for Streatham's Edwardian terraces and mansion blocks along the high road — measured, volume-checked and drawn to Lambeth Council's guidance.
Loft conversion drawings for Kennington's Georgian and Regency terraces near the river — measured, volume-checked and drawn to Lambeth Council's guidance.
The right loft in Lambeth depends on your roof. This is how the main types compare on planning route and the space they add.
| Loft type | Permitted development? | Space & headroom | What Lambeth Council checks |
|---|---|---|---|
| Rear dormer | Usually yes, within volume limits | Full-height double room at the back | Volume, set-back from eaves, ridge height |
| Hip-to-gable | No — full application | Extends the whole side of the roof | Roof bulk and the symmetry of the pair |
| Mansard | No — full application | Maximum floor area across the roof | Street character, especially in conservation areas |
| Rooflights only | Usually yes (Class C) | Light and headroom, no extra footprint | Whether rooflights sit within the existing slope |
Route depends on your street — conservation areas such as Clapham Old Town and Stockwell Park and Article 4 directions can remove permitted-development rights.
A fixed process built around how Lambeth Council validates and decides householder loft applications — most drawings are submission-ready within seven days of survey.
Tell us your Lambeth postcode and roof type. We confirm your conservation and Article 4 status, how much permitted-development volume you have left, and score your odds against live Lambeth Council decisions.
We measure ridge and eaves heights, roof pitch, joist levels and the existing stair — the numbers the volume calculation and head heights depend on.
Chartered designers develop the dormer, hip-to-gable or mansard to your brief, drawn inside the Class B limits or to Lambeth Council's roof-alteration guidance.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until Lambeth Council issues its decision.
Often not. A rear dormer within 40 cubic metres on a terrace, or 50 on a semi-detached or detached house, set back from the eaves and no higher than the ridge, is usually permitted development. In Lambeth the main exceptions are hip-to-gable conversions, dormers visible from the highway, and homes in conservation areas such as Clapham Old Town and Stockwell Park or on streets with an Article 4 direction. Lambeth Council is the decision-maker.
Generally no. In conservation areas including Clapham Old Town and Stockwell Park, Class B permitted-development rights for lofts are removed, so a rear dormer that would be lawful elsewhere needs a full application to Lambeth Council. Alongside the controls in conservation areas such as Clapham Old Town, Lambeth runs a borough-wide Article 4 direction removing permitted-development rights for small shared houses, pulling many HMO changes into the application system. We check your exact address before drawing.
On butterfly and valley roofs behind the terrace parapets, common across Lambeth, a rear dormer is usually the most efficient conversion and often permitted development. Where the roof is mansard and pitched roofs on the taller stucco streets, a hip-to-gable followed by a rear dormer gains far more usable space but needs planning permission. Our survey confirms which your roof supports before we draw. Lambeth Council is the decision-maker.
A householder planning application in Lambeth runs to a statutory eight-week target, and a lawful development certificate to eight weeks as well, though validation can add time if the pack is incomplete. We submit validation-complete drawings and manage case-officer queries to keep the decision on track. Lambeth Council is the decision-maker.
If your dormer is permitted development, a lawful development certificate from Lambeth Council is council-stamped proof of that — worth having, because every buyer's solicitor will ask for it when you sell. We prepare and submit the certificate application with the same drawing pack.
Every roof is different, so we quote each Lambeth project individually — a fixed, no-obligation price back within one working day. The quote covers the full drawing pack with free revisions until Lambeth Council approves, and we tell you upfront whether your loft qualifies as permitted development. Call 020 7864 7245 to start.
Answer five quick questions and get a free planning score for your exact address — instantly. Then, if you want the full picture, unlock the detailed analysis: your council's live approval rates, local precedents, constraints on your street and a step-by-step route to permission.
Same fixed quotes, same fast drawings — wherever your project is.