Back-of-house extension drawings for Lambeth homes — the glazed kitchen-diner across the rear, drawn to Lambeth Council's depth and daylight limits, delivered in days and revised free until your decision, with a free approval-odds check 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.
The rear extension is the workhorse of Lambeth home improvement — it is how a dark back kitchen becomes an open family room facing the garden. Because the borough is built largely from Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and estates, most back walls sit close to a neighbour on at least one side, and that proximity, not the design, is what Lambeth Council scrutinises. The council reads the proposal against Lambeth Local Plan and the council's Alterations and Extensions SPD, and the first line an officer draws is the 45-degree splay from the neighbour's nearest window.
So the drawings live or die on geometry. We set the depth against the exact permitted-development figure, hold the eaves and the flat-roof or lantern build-up under the 4-metre height ceiling, and show the projection tested against both the 45-degree plan angle and the 25-degree section angle to the neighbouring windows. The loss of family houses to further flat conversion is resisted and frequently the deciding issue, so the rear elevation is composed around it rather than corrected after an objection.
Where the property sits in a conservation area — Clapham Old Town, Stockwell Park, Angell Town, Herne Hill and Leigham Court Estate among Lambeth's — the larger-home extension route is switched off and even a modest rear addition needs consent. 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 confirm the designation before the survey.
Many single-storey rear extensions in Lambeth are permitted development and need no application. You will normally need to apply to Lambeth Council, or use the larger-home prior-approval route, if any of these apply:
We draw the depth, the roof build-up and the daylight splays to each neighbour on the page — the tests Lambeth Council's officers apply first — and submit a validation-complete pack, whether that is a lawful development certificate, a larger-home prior-approval notice or a full householder application.
Below is Lambeth Council's real householder decision record, taken from official planning statistics and refreshed 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. Rear extensions turn most often on neighbour daylight and depth, so a drawing pack that proves those tests upfront is decided 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 Clapham, Brixton and Stockwell, the approved rear extension is typically a single-storey glazed box within the depth limit, roofed either flat with a lantern or in a shallow mono-pitch, and finished in brick or render to match the host wall. On the borough's georgian and victorian terraces, keeping the projection to the permitted-development figure often avoids an application entirely; where owners want the full 6 metres, the larger-home route succeeds when the neighbour-consultation period passes without a sustained objection.
Mansards and roof additions on stucco-fronted terraces are measured against whatever original roofline survives on the street. We keep the extension inside the daylight splays, set any glazed roof below the first-floor cill, and retain the garden depth Lambeth Council expects — so the back elevation answers the amenity case before a neighbour can lodge one. Two-storey rear extensions we draw with the 7-metre boundary gap and privacy screening resolved on the plan.
We draw rear extensions on every street in the borough. A few of the neighbourhoods where Lambeth back-of-house projects come up most often:
Rear extension drawings for Clapham's Georgian and Victorian terraces around the Old Town and Common — depth-checked, daylight-tested and drawn to Lambeth Council's guidance.
Rear extension drawings for Brixton's Victorian terraces heavily subdivided into flats — depth-checked, daylight-tested and drawn to Lambeth Council's guidance.
Rear extension drawings for Stockwell's Georgian and Victorian streets around Stockwell Park — depth-checked, daylight-tested and drawn to Lambeth Council's guidance.
Rear extension drawings for Herne Hill's Victorian villas and terraces on the Dulwich fringe — depth-checked, daylight-tested and drawn to Lambeth Council's guidance.
Rear extension drawings for Streatham's Edwardian terraces and mansion blocks along the high road — depth-checked, daylight-tested and drawn to Lambeth Council's guidance.
Rear extension drawings for Kennington's Georgian and Regency terraces near the river — depth-checked, daylight-tested and drawn to Lambeth Council's guidance.
How far you can extend at the back in Lambeth depends on your house type and the route you take. This is how the options compare.
| Route | Depth allowed | Consent needed | What Lambeth Council checks |
|---|---|---|---|
| Standard permitted development | 3m terrace/semi · 4m detached | Lawful development certificate (optional) | Depth, 4m height, materials |
| Larger-home prior approval | 6m terrace/semi · 8m detached | Prior-approval notice + neighbour consultation | Neighbour objections on amenity |
| Full householder application | Beyond the above, or two-storey | Full planning permission | Daylight (45°/25°), bulk, garden retained |
| Conservation area | Case by case | Full planning permission | Character, roof form, boundary treatment |
The larger-home route is switched off on designated land — conservation areas such as Clapham Old Town and Stockwell Park and Article 4 streets need a full application.
A fixed process built around how Lambeth Council validates and decides rear-extension applications — most drawings are submission-ready within seven days of survey.
Send us your Lambeth postcode and house type. We confirm your conservation and Article 4 status, how much rear-extension depth you have under permitted development, and score your odds against live Lambeth Council decisions.
We measure the original rear wall, floor and eaves levels, side and rear boundary distances and the neighbours' window positions — the numbers the depth limit and daylight splays depend on.
Chartered designers develop the single or two-storey rear extension to your brief, drawn inside the permitted-development limits or to Lambeth Council's extension design guidance, with the daylight angles shown.
We submit the certificate, prior-approval notice or application, handle validation and case-officer queries, and revise the drawings free until Lambeth Council issues its decision.
Often not. A single-storey rear extension up to 3 metres deep on a terrace or semi, or 4 metres on a detached house, and no higher than 4 metres, is usually permitted development in Lambeth. You will need to involve Lambeth Council for anything deeper via the larger-home route, for two-storey rear extensions, and for any rear extension in a conservation area such as Clapham Old Town and Stockwell Park, where those permitted-development rights fall away.
The larger-home extension scheme lets a single-storey rear extension reach 6 metres on a terrace or semi, or 8 metres on a detached house — double the standard allowance. It is not automatic: you submit a prior-approval notification to Lambeth Council, neighbours are consulted, and if one objects on amenity grounds the council rules on it. It also does not apply on designated land such as Lambeth's conservation areas.
It is the daylight test Lambeth Council applies to protect neighbours. Drawn on plan, a line at 45 degrees from the midpoint of the neighbour's nearest ground-floor window should not be crossed by your extension; a companion 25-degree line is checked in section. If the projection breaches it, the extension is likely to be shortened or refused, so we test and prove it on the drawings before submission.
A two-storey rear extension almost always needs a full householder application to Lambeth Council, as it sits outside permitted development on most homes. The council checks that it stays at least 7 metres from the rear boundary, does not overbear the neighbours and avoids new overlooking. We resolve the boundary gap, privacy and daylight on the plans so the application is decided on its merits.
Frequently, yes. If the rear extension involves work to a shared wall, building up to the boundary, or excavating foundations near a neighbour's structure, the Party Wall etc. Act applies and you must serve notice — this is separate from Lambeth Council's planning decision. We flag it early and can prepare the drawings a party-wall surveyor needs alongside the planning set.
We price each Lambeth rear extension on its own footprint and send a fixed, no-obligation quote within one working day. It covers the full drawing pack with free revisions until Lambeth Council approves, and we confirm at the outset whether your extension is permitted development, needs prior approval, or a full application. Call 020 7864 7245 to begin.
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Same fixed quotes, same fast drawings — wherever your project is.