The fast route to a deep single-storey rear extension in Lewisham — up to 6 metres on an attached house or 8 on a detached one — via Lewisham Council's prior approval scheme rather than a full planning application.
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 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 Blackheath and Telegraph Hill 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.
Lewisham is largely Victorian terraces, Victorian and Edwardian villas and converted flats and maisonettes. Policies resist the loss of family-sized houses, so conversions to flats face an added hurdle, which matters here because an objecting neighbour puts amenity squarely in front of a case officer. 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.
The scheme is available where all of these hold. Fail any one and it is a full application to Lewisham Council instead:
We prepare the notification pack Lewisham 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 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. 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 Blackheath, Brockley and Telegraph Hill, 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.
In the Brockley and Telegraph Hill conservation areas original slate roofs and front elevations are closely guarded. 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 Lewisham. A few of the areas where deep rear extensions come up most often:
Prior approval drawings for Blackheath — grand villas and terraces on the Lewisham side of the heath — dimensioned to the 6m and 8m limits and prepared for Lewisham Council's neighbour consultation.
Prior approval drawings for Brockley — long Victorian terraces within one of London's largest conservation areas — dimensioned to the 6m and 8m limits and prepared for Lewisham Council's neighbour consultation.
Prior approval drawings for Telegraph Hill — hilly Victorian terraces framing the two parks — dimensioned to the 6m and 8m limits and prepared for Lewisham Council's neighbour consultation.
Prior approval drawings for Deptford — Georgian survivals like Albury Street amid dense terraced streets — dimensioned to the 6m and 8m limits and prepared for Lewisham Council's neighbour consultation.
Prior approval drawings for Forest Hill — Victorian villas and terraces stepping up the slopes — dimensioned to the 6m and 8m limits and prepared for Lewisham Council's neighbour consultation.
Prior approval drawings for Sydenham — Victorian terraces and semis toward the Crystal Palace ridge — dimensioned to the 6m and 8m limits and prepared for Lewisham 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 Lewisham 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 Lewisham 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 Lewisham 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 Lewisham 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 Lewisham address specifically. Lewisham Council is the decision-maker.
No. The larger home extension scheme is unavailable on designated land, which includes conservation areas such as Blackheath and Telegraph Hill, 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 Lewisham 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 Lewisham address specifically. Lewisham 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 Lewisham address specifically. Lewisham Council is the decision-maker.
We quote each Lewisham 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 Lewisham Council determines it. 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.