Back-of-house extension drawings for Patcham homes — the glazed kitchen-diner across the rear, drawn to Brighton & Hove City Council's depth and daylight limits, delivered in days and revised free until your decision, with a free approval-odds check first.
Brighton & Hove City 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 northern edges of Patcham and Withdean adjoin the South Downs National Park, where development on the open downland fringe is tightly restrained, which is where a policy-literate drawing pack earns its keep. Its dominant interwar (1918–1939) 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. Patcham carries at least one Article 4 direction, and conservation areas including Patcham and Tongdean remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Patcham is determined against an 8-week statutory target.
Old Patcham (the flint village core around All Saints church and the Black Lion), Ladies Mile (sweeping interwar semi-detached avenues on the downland slope), Tongdean (large detached 20th-century houses in a wooded conservation setting), Withdean (1930s semis and detached villas around the stadium and woods), Patcham Place (housing set against the Grade II* manor and its park) and Carden fringe (postwar suburban estates on the northern edge) — these are the Patcham pockets our drawings cover most. Heritage designations here include Patcham and Tongdean. Brighton & Hove City Council weighs each proposal against Brighton & Hove City Plan (Parts One 2016 and Two 2022) and the relevant SPDs, where the flint village core of Old Patcham and the wooded Tongdean estate are protected against alterations that would erode their established character. Pockets of larger houses around Withdean and Patcham have been converted into flats, which sit outside householder permitted-development rights.. On roofs the borough is hipped roofs on the interwar semis and bungalows and pitched clay-tiled roofs on the village cottages and larger villas, over interwar semi-detached houses and bungalows, the historic flint core of Old Patcham, large 20th-century detached houses at Tongdean and mock-Tudor and 1930s suburban villas.
The rear extension is the workhorse of Patcham home improvement — it is how a dark back kitchen becomes an open family room facing the garden. Because the borough is built largely from interwar semi-detached houses and bungalows, the historic flint core of Old Patcham, large 20th-century detached houses at Tongdean and mock-Tudor and 1930s suburban villas, most back walls sit close to a neighbour on at least one side, and that proximity, not the design, is what Brighton & Hove City Council scrutinises. The council reads the proposal against Brighton & Hove City Plan (Parts One 2016 and Two 2022) and the relevant SPDs, 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 northern edges of Patcham and Withdean adjoin the South Downs National Park, where development on the open downland fringe is tightly restrained, so the rear elevation is composed around it rather than corrected after an objection.
Where the property sits in a conservation area — Patcham and Tongdean among Patcham's — the larger-home extension route is switched off and even a modest rear addition needs consent. Patcham is covered by the city-wide small-HMO Article 4 direction, while the Patcham conservation area — the historic downland village designated in 1970 — and the neighbouring Tongdean conservation area (designated 1989) protect their older cores from unrestricted alteration. We confirm the designation before the survey.
Many single-storey rear extensions in Patcham are permitted development and need no application. You will normally need to apply to Brighton & Hove City 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 Brighton & Hove City 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 Brighton & Hove City Council's real householder decision record, taken from official planning statistics and refreshed as new data lands. The council grants a high share of householder applications, and across Patcham and Withdean the main pressures are the South Downs National Park fringe to the north and keeping roof alterations in step with the interwar streets. 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, England, 1 April 2025 - 31 March 2026). 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 Old Patcham, Ladies Mile and Tongdean, 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 interwar semi-detached houses and bungalows, 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.
The flint village core of Old Patcham and the wooded Tongdean estate are protected against alterations that would erode their established character. We keep the extension inside the daylight splays, set any glazed roof below the first-floor cill, and retain the garden depth Brighton & Hove City 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 Patcham back-of-house projects come up most often:
Rear extension drawings for Old Patcham's the flint village core around All Saints church and the Black Lion — depth-checked, daylight-tested and drawn to Brighton & Hove City Council's guidance.
Rear extension drawings for Ladies Mile's sweeping interwar semi-detached avenues on the downland slope — depth-checked, daylight-tested and drawn to Brighton & Hove City Council's guidance.
Rear extension drawings for Tongdean's large detached 20th-century houses in a wooded conservation setting — depth-checked, daylight-tested and drawn to Brighton & Hove City Council's guidance.
Rear extension drawings for Withdean's 1930s semis and detached villas around the stadium and woods — depth-checked, daylight-tested and drawn to Brighton & Hove City Council's guidance.
Rear extension drawings for Patcham Place's housing set against the Grade II* manor and its park — depth-checked, daylight-tested and drawn to Brighton & Hove City Council's guidance.
Rear extension drawings for Carden fringe's postwar suburban estates on the northern edge — depth-checked, daylight-tested and drawn to Brighton & Hove City Council's guidance.
How far you can extend at the back in Patcham depends on your house type and the route you take. This is how the options compare.
| Route | Depth allowed | Consent needed | What Brighton & Hove City 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 Patcham and Tongdean and Article 4 streets need a full application.
A fixed process built around how Brighton & Hove City Council validates and decides rear-extension applications — most drawings are submission-ready within seven days of survey.
Send us your Patcham 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 Brighton & Hove City 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 Brighton & Hove City 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 Brighton & Hove City 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 Patcham. You will need to involve Brighton & Hove City 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 Patcham and Tongdean, 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 Brighton & Hove City 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 Patcham's conservation areas.
It is the daylight test Brighton & Hove City 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. This applies to your Patcham address specifically.
A two-storey rear extension almost always needs a full householder application to Brighton & Hove City 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. This applies to your Patcham address specifically.
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 Brighton & Hove City Council's planning decision. We flag it early and can prepare the drawings a party-wall surveyor needs alongside the planning set. This applies to your Patcham address specifically.
We price each Patcham 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 Brighton & Hove City 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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