Back-of-house extension drawings for West Downs homes — the glazed kitchen-diner across the rear, drawn to Swale Borough Council's depth and daylight limits, delivered in days and revised free until your decision, with a free approval-odds check first.
Swale Borough Council granted 94% of the householder planning decisions it made in its latest published year — 7 points above the 87% England-wide householder average. West Downs contains Bexon, Bredgar, Milstead conservation areas (Bexon designated 2026), so materials, fenestration and roof form are assessed against the appraisal, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901) and postwar (1945–1970) 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. West Downs carries at least one Article 4 direction, and conservation areas including Bexon, Bredgar and Milstead remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in West Downs is determined against an 8-week statutory target.
Bexon (conservation area designated in 2026), Bredgar (conservation area designated in 1973), Milstead (conservation area designated in 1973), Rodmersham Church Street (conservation area designated in 2022), Rodmersham Green (conservation area designated in 1974), Tunstall (conservation area designated in 1973), Bapchild (civil parish within West Downs), Bredgar (civil parish within West Downs), Milstead (civil parish within West Downs), Rodmersham (civil parish within West Downs) and Tunstall (civil parish within West Downs) — these are the West Downs pockets our drawings cover most. Heritage designations here include Bexon, Bredgar, Milstead, Rodmersham Church Street, Rodmersham Green and Tunstall. Swale Borough Council weighs each proposal against Swale Borough Council's adopted local plan and its householder design guidance, where the 1,410 homes here are 17% pre-1900, 13% 1973-1982, 10% 1955-1964, which is what sets the realistic roof and rear-projection options. On roofs the borough is steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and shallow trussed roofs typical of 1970s building, over Victorian and earlier houses (17% of 1,410 homes), 1970s and early-1980s houses (13%) and late-1950s and early-1960s houses (10%).
What is permitted in West Downs turns on designation first, so that is where we start: Bexon (conservation area designated in 2026), Bredgar (conservation area designated in 1973), Milstead (conservation area designated in 1973), Rodmersham Church Street (conservation area designated in 2022), Rodmersham Green (conservation area designated in 1974) and Tunstall (conservation area designated in 1973). Inside those boundaries permitted development is curtailed and Swale Borough Council assesses materials, window detail and roof form against the area's own appraisal, so a scheme that would be waved through two streets away can need a full application here.
Beyond the designated areas, West Downs takes in Bapchild, Bredgar, Milstead, Rodmersham and Tunstall. Swale Borough Council has 22 recorded Article 4 directions, removing permitted development for rear and side extensions — check the address before assuming PD applies in West Downs.
On stock, West Downs is Victorian and earlier houses (17% of 1,410 homes), 1970s and early-1980s houses (13%) and late-1950s and early-1960s houses (10%) — which is why steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and shallow trussed roofs typical of 1970s building govern what a loft or rear projection can realistically be. Swale Borough Council decided 329 householder applications in the latest published year and granted 94%, with 37% issued inside the eight-week target. We draw to that record rather than to a national average.
The full build-period split for West Downs runs pre-1900 17% (240 homes), 1900-1918 2% (30 homes), 1919-1929 3% (40 homes), 1930-1939 7% (100 homes), 1945-1954 7% (100 homes), 1955-1964 10% (140 homes), 1965-1972 4% (60 homes), 1973-1982 13% (180 homes), 1983-1992 1% (20 homes), 1993-1999 3% (40 homes) and 2000-2008 9% (120 homes). That distribution is why pre-1900 detailing dominates the drawings here, and it is measured from council-tax records rather than assumed from the street name.
Swale Borough Council also decides for Abbey, Borden and Grove Park, Boughton and Courtenay, East Downs, Sheerness, Teynham and Lynsted and Watling, so a decision in West Downs sits inside a wider pattern of decisions we track across the same authority — useful when an officer cites a precedent from the next area over.
The Article 4 directions recorded for this council include 1 and 2 Flint Cottages, 20 East Street, 43-47, 49-51, 54, 56, 57, 59-72 Marine Parade and 49, 88, 90, 104, 114-128(evens), 132-140(evens) The Street and 1 & 2 Chapel Cottages. Each removes a specific permitted-development right inside its own boundary, which is why the check is done on the address rather than on the town.
Published figures for West Downs and Swale Borough Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | West Downs |
|---|---|
| Dwellings recorded | 1,410 |
| Built pre-1900 | 240 (17%) |
| Built 1900-1918 | 30 (2%) |
| Built 1919-1929 | 40 (3%) |
| Built 1930-1939 | 100 (7%) |
| Built 1945-1954 | 100 (7%) |
| Built 1955-1964 | 140 (10%) |
| Built 1965-1972 | 60 (4%) |
| Built 1973-1982 | 180 (13%) |
| Built 1983-1992 | 20 (1%) |
| Built 1993-1999 | 40 (3%) |
| Built 2000-2008 | 120 (9%) |
| Built before 1919 | 19% |
| Built 1919–1939 | 10% |
| Built 1945–2008 | 47% |
| Conservation areas in West Downs | 6 (Bexon, Bredgar…) |
| Conservation areas district-wide | 52 |
| Article 4 directions recorded | 22 |
| Householder applications decided | 329 |
| Householder applications granted | 94% |
| Decided within 8 weeks | 37% |
Dwelling stock from VOA council-tax data at 31 March 2025; conservation-area and Article 4 counts from planning.data.gov.uk (MHCLG); decision figures are Swale Borough Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
The rear extension is the workhorse of West Downs home improvement — it is how a dark back kitchen becomes an open family room facing the garden. Because the borough is built largely from Victorian and earlier houses (17% of 1,410 homes), 1970s and early-1980s houses (13%) and late-1950s and early-1960s houses (10%), most back walls sit close to a neighbour on at least one side, and that proximity, not the design, is what Swale Borough Council scrutinises. The council reads the proposal against Swale Borough Council's adopted local plan and its householder design guidance, 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. West Downs contains Bexon, Bredgar, Milstead conservation areas (Bexon designated 2026), so materials, fenestration and roof form are assessed against the appraisal, so the rear elevation is composed around it rather than corrected after an objection.
Where the property sits in a conservation area — Bexon, Bredgar, Milstead, Rodmersham Church Street, Rodmersham Green and Tunstall among West Downs's — the larger-home extension route is switched off and even a modest rear addition needs consent. Swale Borough Council has 22 recorded Article 4 directions, removing permitted development for rear and side extensions — check the address before assuming PD applies in West Downs. We confirm the designation before the survey.
Many single-storey rear extensions in West Downs are permitted development and need no application. You will normally need to apply to Swale Borough 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 Swale Borough 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 Swale Borough Council's real householder decision record, taken from official planning statistics and refreshed as new data lands. Swale Borough Council granted 94% of its householder applications in the year to 31 March 2026, and Bexon shapes what is approved here. 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 Bexon, Bredgar and Milstead, 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 victorian and earlier houses (17% of 1,410 homes), 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 1,410 homes here are 17% pre-1900, 13% 1973-1982, 10% 1955-1964, which is what sets the realistic roof and rear-projection options. We keep the extension inside the daylight splays, set any glazed roof below the first-floor cill, and retain the garden depth Swale Borough 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 West Downs back-of-house projects come up most often:
Rear extension drawings for Bexon's conservation area designated in 2026 — depth-checked, daylight-tested and drawn to Swale Borough Council's guidance.
Rear extension drawings for Bredgar's conservation area designated in 1973 — depth-checked, daylight-tested and drawn to Swale Borough Council's guidance.
Rear extension drawings for Milstead's conservation area designated in 1973 — depth-checked, daylight-tested and drawn to Swale Borough Council's guidance.
Rear extension drawings for Rodmersham Church Street's conservation area designated in 2022 — depth-checked, daylight-tested and drawn to Swale Borough Council's guidance.
Rear extension drawings for Rodmersham Green's conservation area designated in 1974 — depth-checked, daylight-tested and drawn to Swale Borough Council's guidance.
Rear extension drawings for Tunstall's conservation area designated in 1973 — depth-checked, daylight-tested and drawn to Swale Borough Council's guidance.
How far you can extend at the back in West Downs depends on your house type and the route you take. This is how the options compare.
| Route | Depth allowed | Consent needed | What Swale Borough 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 Bexon and Bredgar and Article 4 streets need a full application.
A fixed process built around how Swale Borough Council validates and decides rear-extension applications — most drawings are submission-ready within seven days of survey.
Send us your West Downs 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 Swale Borough 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 Swale Borough 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 Swale Borough 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 West Downs. You will need to involve Swale Borough 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 Bexon and Bredgar, 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 Swale Borough 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 West Downs's conservation areas.
It is the daylight test Swale Borough 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 West Downs address specifically.
A two-storey rear extension almost always needs a full householder application to Swale Borough 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 West Downs 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 Swale Borough 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 West Downs address specifically.
We price each West Downs 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 Swale Borough 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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