The fast route to a deep single-storey rear extension in Southwark — up to 6 metres on an attached house or 8 on a detached one — via Southwark Council's prior approval scheme rather than a full planning application.
Southwark Council granted 89% of the householder planning decisions it made in its latest published year — 2 points above the 87% England-wide householder average. Mansards and roof extensions on terraces are assessed against the established roofline and the conservation-area appraisal, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837), Victorian (1837–1901) and postwar (1945–1970) 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. Southwark carries at least one Article 4 direction, and conservation areas including Camberwell Grove, Dulwich Village and Bermondsey Street remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Southwark is determined against an 8-week statutory target.
Camberwell (Georgian and Victorian terraces around Camberwell Grove), Dulwich (villas and the Dulwich Village conservation area under the Dulwich Estate), Bermondsey (warehouse conversions and terraces off Bermondsey Street), Peckham (Victorian terraces including the Holly Grove enclave), Nunhead (modest Victorian terraces near Nunhead Green and the cemetery) and Walworth (dense Georgian and Victorian terraces threaded through large estates) — these are the Southwark pockets our drawings cover most. Heritage designations here include Camberwell Grove, Dulwich Village, Bermondsey Street, Holly Grove and Nunhead Green. Southwark Council weighs each proposal against the Southwark Plan and the borough's Residential Design Standards SPD, where the borough runs detailed basement and residential design standards on top of the usual tests. Camberwell, Peckham and the warehouse quarters around Bermondsey are heavily subdivided into flats, none of which hold householder permitted-development rights.. On roofs the borough is butterfly and parapet roofs on the terraces and flat and pitched roofs on the former warehouses, over Georgian and Victorian terraces, former warehouse and industrial conversions and Dulwich villas and postwar estates.
The ordinary Class A limits stop a single-storey rear extension at 3 metres on an attached house and 4 on a detached one. The larger home extension scheme doubles both, on condition that the council is told first. That notification is not an application for permission — the council cannot refuse on design, materials or policy grounds. It can only consider the effect on the amenity of adjoining premises, and only if a neighbour actually objects during the 21-day consultation.
The other conditions still apply and are strict: single storey only, no higher than 4 metres, eaves no higher than the existing eaves, and no more than half the land around the original house covered. It is not available on designated land, so a house in a conservation area such as Camberwell Grove and Dulwich Village cannot use it at all. Materials must be similar to the existing house, and the extension must not include a veranda, balcony or raised platform.
Southwark is largely Georgian and Victorian terraces, former warehouse and industrial conversions and Dulwich villas and postwar estates. Mansards and roof extensions on terraces are assessed against the established roofline and the conservation-area appraisal, which matters here because an objecting neighbour puts amenity squarely in front of a case officer. Southwark carries numerous Article 4 directions across conservation areas such as Camberwell Grove and Bermondsey Street, while the Dulwich Estate's scheme of management adds a separate layer of consent in Dulwich.
The scheme is available where all of these hold. Fail any one and it is a full application to Southwark Council instead:
We prepare the notification pack Southwark Council needs — plans, elevations, a site plan with the adjoining owners identified — and manage the 21-day neighbour consultation so the 42-day clock is not restarted by an incomplete submission.
Below is Southwark Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Southwark grants most householder applications, but heavy conservation-area coverage, its basement policies and the Dulwich Estate's scheme of management dictate what is achievable in many neighbourhoods. Prior approval turns on neighbour amenity alone, so the drawings that matter are the ones showing the relationship to the boundary.
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 Camberwell, Dulwich and Bermondsey, the notifications that clear without objection are the ones that treat the neighbour as the audience. We show the extension in section against the boundary, demonstrate the 45-degree daylight relationship to the nearest habitable window, and where the plot is tight we taper the depth away from the boundary rather than running the full 6 metres to the fence.
The borough runs detailed basement and residential design standards on top of the usual tests. Where an objection does arrive, the council's assessment is narrow: loss of light, outlook and overbearing effect on the adjoining property, nothing else. A pack that has already answered those three points on the drawings usually survives an objection, whereas one that leaves them to the officer's imagination usually does not.
We prepare prior-approval notifications across Southwark. A few of the areas where deep rear extensions come up most often:
Prior approval drawings for Camberwell — Georgian and Victorian terraces around Camberwell Grove — dimensioned to the 6m and 8m limits and prepared for Southwark Council's neighbour consultation.
Prior approval drawings for Dulwich — villas and the Dulwich Village conservation area under the Dulwich Estate — dimensioned to the 6m and 8m limits and prepared for Southwark Council's neighbour consultation.
Prior approval drawings for Bermondsey — warehouse conversions and terraces off Bermondsey Street — dimensioned to the 6m and 8m limits and prepared for Southwark Council's neighbour consultation.
Prior approval drawings for Peckham — Victorian terraces including the Holly Grove enclave — dimensioned to the 6m and 8m limits and prepared for Southwark Council's neighbour consultation.
Prior approval drawings for Nunhead — modest Victorian terraces near Nunhead Green and the cemetery — dimensioned to the 6m and 8m limits and prepared for Southwark Council's neighbour consultation.
Prior approval drawings for Walworth — dense Georgian and Victorian terraces threaded through large estates — dimensioned to the 6m and 8m limits and prepared for Southwark Council's neighbour consultation.
Same extension, two routes, very different tests.
| Route | Depth allowed | What the council may consider | Timescale |
|---|---|---|---|
| Ordinary Class A permitted development | 3m attached / 4m detached | Nothing — no application needed | Immediate |
| Larger home extension prior approval | 6m attached / 8m detached | Amenity of adjoining premises, only if a neighbour objects | 21-day consultation, 42-day determination |
| Full householder application | No fixed limit | Design, materials, policy, amenity, everything | 8-week target |
| Any of these on designated land | 3m / 4m only | Prior approval scheme unavailable | Full application beyond the limits |
Limits and procedure from the GPDO 2015, Schedule 2, Part 1, Class A and paragraph A.4, made permanent by amendment in 2019.
A process built around the 21-day consultation, which is where these schemes are won or lost.
Send us your Southwark postcode and house type. We confirm whether the property is on designated land, whether the scheme is available, and what depth you can realistically take.
We measure the original rear wall, eaves height, boundary distances and the neighbouring windows that the amenity assessment will turn on.
We draw the extension to the 6m or 8m limit with the boundary relationship shown in section, and prepare the written description and adjoining-owner details Southwark Council needs to start the consultation.
We submit, track the 21-day consultation and the 42-day determination, respond to any objection on amenity grounds, and revise free until the decision.
Three metres on a terraced or semi-detached house and four on a detached one under ordinary permitted development. Under the larger home extension prior approval scheme those double to six and eight metres, provided you notify Southwark Council before starting and the conditions on height, materials and land coverage are met. The scheme is not available on designated land.
It is a notification, not an application for permission. You tell Southwark Council what you intend to build, it writes to the adjoining owners, and they have 21 days to object. If nobody objects, you may build. If someone does, the council assesses the effect on the amenity of adjoining premises and must decide within 42 days. Design and policy are not in scope.
The council then considers the impact on the amenity of the adjoining property — loss of light, loss of outlook, and overbearing effect — and nothing else. It cannot refuse because it dislikes the design or the materials. We prepare the drawings so those three questions are already answered in section and on the site plan, which is what usually carries an objected scheme through. This applies to your Southwark address specifically. Southwark Council is the decision-maker.
No. The larger home extension scheme is unavailable on designated land, which includes conservation areas such as Camberwell Grove and Dulwich Village, national landscapes, national parks and world heritage sites. On those properties the ordinary 3-metre and 4-metre limits apply, and anything deeper needs a full householder application to Southwark Council.
Twenty-one days for the neighbour consultation, and a maximum of 42 days from a valid submission for the council to determine it. If the council does not respond within 42 days you may proceed as notified. That deadline is the scheme's real advantage over a full application, and it is why validation completeness matters so much. This applies to your Southwark address specifically. Southwark Council is the decision-maker.
Yes — always. Prior approval deals only with the planning position. A 6-metre rear extension still needs building control approval for foundations, structure, drainage, thermal performance and fire safety, and the beam over the opening into the existing house needs designing and calculating. We prepare both sets so the notified scheme is the buildable one. This applies to your Southwark address specifically. Southwark Council is the decision-maker.
We quote each Southwark scheme individually, because plot shape and the boundary relationship drive the work, and send a fixed, no-obligation quote within one working day. It covers the notification pack and free revisions until Southwark Council determines it. Call 020 7864 7245 to start.
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Same fixed quotes, same fast drawings — wherever your project is.