Single-storey, double-storey, rear and side extension drawings for South East Purbeck homes — measured to Dorset Council's design guidance, delivered in days and revised free until your decision, with a free approval-odds check before you commit.
Dorset Council granted 95% of the householder planning decisions it made in its latest published year — 8 points above the 87% England-wide householder average. South East Purbeck contains Acton Conservation Area 1, Acton Conservation Area 2, Church Knowle Conservation Area conservation areas (Acton Conservation Area 1 designated 1975), 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.
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. South East Purbeck carries at least one Article 4 direction, and conservation areas including Acton Conservation Area 1, Acton Conservation Area 2 and Church Knowle Conservation Area remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in South East Purbeck is determined against an 8-week statutory target.
Acton Conservation Area 1 (conservation area designated in 1975), Acton Conservation Area 2 (conservation area designated in 1975), Church Knowle (conservation area designated in 1981), Corfe Castle (conservation area designated in 1971), East Creech (conservation area designated in 1990), East Holme (conservation area designated in 1990), Kimmeridge (conservation area designated in 1975), Kingston (conservation area designated in 1975), Langton Matravers Conservation Area 1 (conservation area designated in 1976), Langton Matravers Conservation Area 2 (conservation area designated in 1976), Studland (conservation area designated in 1991), Worth Matravers (conservation area designated in 1975), Church Knowle (civil parish within South East Purbeck), East Holme (civil parish within South East Purbeck), East Stoke (civil parish within South East Purbeck), Kimmeridge (civil parish within South East Purbeck), Langton Matravers (civil parish within South East Purbeck) and Studland (civil parish within South East Purbeck) — these are the South East Purbeck pockets our drawings cover most. Heritage designations here include Acton Conservation Area 1, Acton Conservation Area 2, Church Knowle Conservation Area, Corfe Castle Conservation Area, East Creech Conservation Area, East Holme Conservation Area, Kimmeridge Conservation Area, Kingston Conservation Area, Langton Matravers Conservation Area 1, Langton Matravers Conservation Area 2, Studland Conservation Area and Worth Matravers Conservation Area. Dorset Council weighs each proposal against the adopted Dorset local plan and Dorset Council's design guidance for householder work, where the 1,930 homes here are 30% pre-1900, 10% 1945-1954, 9% 1983-1992, 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 simple gabled and hipped roofs typical of early postwar building, over Victorian and earlier houses (30% of 1,930 homes), early postwar houses (10%) and 1980s estate houses (9%).
South East Purbeck's designated heritage is specific, and it is the first thing we check against your address: Acton Conservation Area 1 (conservation area designated in 1975), Acton Conservation Area 2 (conservation area designated in 1975), Church Knowle (conservation area designated in 1981), Corfe Castle (conservation area designated in 1971), East Creech (conservation area designated in 1990), East Holme (conservation area designated in 1990), Kimmeridge (conservation area designated in 1975), Kingston (conservation area designated in 1975), Langton Matravers Conservation Area 1 (conservation area designated in 1976), Langton Matravers Conservation Area 2 (conservation area designated in 1976), Studland (conservation area designated in 1991) and Worth Matravers (conservation area designated in 1975). Inside those boundaries permitted development is curtailed and Dorset 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, South East Purbeck takes in Church Knowle, East Holme, East Stoke, Kimmeridge, Langton Matravers and Studland. Dorset Council has 77 recorded Article 4 directions — check the address before assuming PD applies in South East Purbeck.
On stock, South East Purbeck is Victorian and earlier houses (30% of 1,930 homes), early postwar houses (10%) and 1980s estate houses (9%) — which is why steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and simple gabled and hipped roofs typical of early postwar building govern what a loft or rear projection can realistically be. Dorset Council decided 1,261 householder applications in the latest published year and granted 95%, with 78% issued inside the eight-week target. Those are the numbers our drawings are prepared against.
The full build-period split for South East Purbeck runs pre-1900 30% (570 homes), 1900-1918 3% (60 homes), 1919-1929 3% (60 homes), 1930-1939 7% (140 homes), 1945-1954 10% (190 homes), 1955-1964 8% (160 homes), 1965-1972 5% (100 homes), 1973-1982 8% (150 homes), 1983-1992 9% (170 homes), 1993-1999 5% (90 homes) and 2000-2008 3% (60 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.
Dorset Council also decides for Beacon, Beaminster, Blackmore Vale, Blandford, Chalk Valleys, Charminster St Mary's, Chickerell and Cranborne & Alderholt, so a decision in South East Purbeck 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 1-3 The Lane, Kingston, Corfe Castle, 10 Cornwall Road, Swanage, 6 Burlington Road, Swanage and Avon Castle & Matchams Park Estate. 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 South East Purbeck and Dorset Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | South East Purbeck |
|---|---|
| Dwellings recorded | 1,930 |
| Built pre-1900 | 570 (30%) |
| Built 1900-1918 | 60 (3%) |
| Built 1919-1929 | 60 (3%) |
| Built 1930-1939 | 140 (7%) |
| Built 1945-1954 | 190 (10%) |
| Built 1955-1964 | 160 (8%) |
| Built 1965-1972 | 100 (5%) |
| Built 1973-1982 | 150 (8%) |
| Built 1983-1992 | 170 (9%) |
| Built 1993-1999 | 90 (5%) |
| Built 2000-2008 | 60 (3%) |
| Built before 1919 | 33% |
| Built 1919–1939 | 10% |
| Built 1945–2008 | 48% |
| Conservation areas in South East Purbeck | 12 (Acton Conservation Area 1, Acton Conservation Area 2…) |
| Conservation areas district-wide | 311 |
| Article 4 directions recorded | 77 |
| Householder applications decided | 1,261 |
| Householder applications granted | 95% |
| Decided within 8 weeks | 78% |
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 Dorset Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
South East Purbeck homes come in a handful of recurring shapes, and each one points to a different extension. The borough is built largely from Victorian and earlier houses (30% of 1,930 homes), early postwar houses (10%) and 1980s estate houses (9%), so a Victorian terrace usually wants a rear or side-return infill, while an interwar semi has room for a wider single-storey wrap or a two-storey side addition. Dorset Council judges every one of them against the adopted Dorset local plan and Dorset Council's design guidance for householder work, weighing footprint, height and the impact on the house next door before it looks at the elevations.
That is why the drawings decide the outcome. We set the extension depth against the permitted-development limits precisely, keep the eaves and ridge within the allowances, and plot the 45-degree daylight lines to the neighbours' windows so the case officer can see the amenity test is passed. South East Purbeck contains Acton Conservation Area 1, Acton Conservation Area 2, Church Knowle Conservation Area conservation areas (Acton Conservation Area 1 designated 1975), so materials, fenestration and roof form are assessed against the appraisal, so we design around it from the first sketch rather than discover it at validation.
South East Purbeck also protects whole streets — Acton Conservation Area 1, Acton Conservation Area 2, Church Knowle Conservation Area, Corfe Castle Conservation Area, East Creech Conservation Area, East Holme Conservation Area, Kimmeridge Conservation Area, Kingston Conservation Area, Langton Matravers Conservation Area 1, Langton Matravers Conservation Area 2, Studland Conservation Area and Worth Matravers Conservation Area among them. Dorset Council has 77 recorded Article 4 directions — check the address before assuming PD applies in South East Purbeck. On designated land the larger-home extension route and most side extensions stop being permitted development, so we confirm your address against those layers before drawing a line.
Plenty of South East Purbeck extensions are permitted development and need no planning application — a single-storey rear extension within the depth and height limits is the common case. You will normally need to apply to Dorset Council if any of these apply:
We draw the footprint, the ridge and eaves heights and the neighbours' daylight on the page — the relationships Dorset Council's officers weigh first — and submit a validation-complete pack, whether that is a lawful development certificate, a prior-approval notification or a full householder application.
Below is Dorset Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Dorset Council granted 95% of its householder applications in the year to 31 March 2026, and Acton Conservation Area 1 shapes what is approved here. A complete, policy-literate extension pack anticipates those pressure points before submission, which is why professionally drawn applications are decided faster and refused less often than DIY ones.
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 Acton Conservation Area 1, Acton Conservation Area 2 and Church Knowle, the extension that lands most often is the single-storey rear addition — a glazed kitchen-diner across the back of the house, kept within the permitted-development depth or taken to a full application where the ground floor wants more. On the borough's victorian and earlier houses (30% of 1,930 homes), a side-return infill frequently pairs with it to square off the plan; on wider 1980s estate houses (9%), a two-storey side or rear extension can add a bedroom above without swallowing the garden.
The 1,930 homes here are 30% pre-1900, 10% 1945-1954, 9% 1983-1992, which is what sets the realistic roof and rear-projection options. We size the extension to the amenity and daylight tests, match the roof and materials to the host house, and keep enough garden to satisfy Dorset Council's space standards — so the scheme answers the borough's questions before an objection can raise them. Where permitted-development rights are used up or removed, we prepare the householder application to the council's extension design guidance instead.
We draw extensions on every street in the borough. A few of the neighbourhoods where South East Purbeck projects come up most often:
Extension drawings for Acton Conservation Area 1's conservation area designated in 1975 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.
Extension drawings for Acton Conservation Area 2's conservation area designated in 1975 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.
Extension drawings for Church Knowle's conservation area designated in 1981 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.
Extension drawings for Corfe Castle's conservation area designated in 1971 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.
Extension drawings for East Creech's conservation area designated in 1990 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.
Extension drawings for East Holme's conservation area designated in 1990 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.
The right extension in South East Purbeck depends on your house type and how much garden you can give up. This is how the main options compare on planning route and what they add.
| Extension type | Permitted development? | What it adds | What Dorset Council checks |
|---|---|---|---|
| Single-storey rear | Often, within 3m/4m depth (6m/8m via prior approval) | Bigger kitchen-diner across the back | Depth, height, neighbour daylight (45°) |
| Side-return infill | Sometimes, if within width and height limits | Squares off an L-shaped ground floor | Width vs the original house, glazing to boundary |
| Two-storey rear/side | No — full application | Extra bedroom or bathroom above | Bulk, overlooking, 7m rear-boundary gap |
| Wraparound (rear + side) | No — full application | Whole-width open-plan ground floor | Combined footprint and garden retained |
Route depends on your street — conservation areas such as Acton Conservation Area 1 and Acton Conservation Area 2 and Article 4 directions can remove permitted-development rights.
A fixed process built around how Dorset Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.
Tell us your South East Purbeck postcode and house type. We confirm your conservation and Article 4 status, how much permitted-development depth you have left, and score your odds against live Dorset Council decisions.
We measure the existing footprint, floor and eaves levels, boundary distances and the neighbours' window positions — the numbers the depth limits and daylight tests depend on.
Chartered designers develop the single-storey, two-storey or side extension to your brief, drawn inside the permitted-development limits or to Dorset Council's extension design guidance.
We submit the certificate, prior-approval notice or application, manage validation and case-officer queries, and revise the drawings free until Dorset Council issues its decision.
Not always. 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 South East Purbeck you will need to apply to Dorset Council for two-storey extensions, side extensions wider than half the house, anything forward of the front wall, deeper rear extensions under the larger-home prior-approval route, and any extension in a conservation area such as Acton Conservation Area 1 and Acton Conservation Area 2.
Standard permitted development allows 3 metres on a terraced or semi-detached house and 4 metres on a detached one. The larger-home extension scheme can double that to 6 or 8 metres, but it needs a prior-approval notification to Dorset Council and a neighbour-consultation period, and it does not apply on designated land such as South East Purbeck's conservation areas. We confirm which route your property qualifies for before drawing.
Two-storey and double-storey extensions almost always need a full householder application to Dorset Council, because they fall outside permitted development on most homes. The council looks closely at bulk, overlooking of neighbours and the 7-metre gap a two-storey rear extension must keep from the rear boundary. We design to those tests and show the daylight and privacy angles on the drawings. This applies to your South East Purbeck address specifically.
A householder planning application in South East Purbeck runs to a statutory eight-week target, a larger-home prior-approval notification to around six weeks including the neighbour-consultation period, and a lawful development certificate to eight weeks. Incomplete submissions stall at validation, so we submit a complete pack and manage officer queries to keep the decision on schedule. Dorset Council is the decision-maker.
Yes — planning permission and building regulations are separate consents, and almost every extension needs both. Planning governs whether you can build it; building control governs how it is built, covering structure, insulation, drainage and fire safety. We prepare the building-regulations drawings alongside the planning set so Dorset Council's building control or an approved inspector can sign the work off. This applies to your South East Purbeck address specifically.
Every house and brief is different, so we price each South East Purbeck extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Dorset Council approves, and we tell you upfront whether your extension qualifies as permitted development. Call 020 7864 7245 to get started.
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.