Single-storey, double-storey, rear and side extension drawings for Blean Forest homes — measured to Canterbury City Council's design guidance, delivered in days and revised free until your decision, with a free approval-odds check before you commit.
Canterbury City Council granted 97% of the householder planning decisions it made in its latest published year — 10 points above the 87% England-wide householder average. Blean Forest contains ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN ), BLEAN conservation areas (ALLCROFT GRANGE ( HACKINGTON ) designated 1995), so materials, fenestration and roof form are assessed against the appraisal, 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.
Class A and Class B set the thresholds — a rear dormer to 40m³ on a terrace or 50m³ on a semi or detached, and a single-storey rear extension to 3m on a terrace or 4m on a detached house — beyond which Canterbury City Council needs a full application. Blean Forest carries at least one Article 4 direction, and conservation areas including ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN ) and BLEAN remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Blean Forest is determined against an 8-week statutory target.
ALLCROFT GRANGE ( HACKINGTON ) (conservation area designated in 1995), AMERY COURT ( BLEAN ) (conservation area designated in 1995), BLEAN (conservation area designated in 1994), CANTERBURY ( WHITSTABLE ROAD ) Registered 04.12.1996 (conservation area designated in 1996), CANTERBURY AND WHITSTABLE RAILWAY (HACKINGTON & BLEAN) (conservation area designated in 1995), HOTHE COURT (conservation area designated in 1994), the Tyler Hill Conservation Area. Registered 27.03.1995 (conservation area designated in 1995), Hackington (civil parish within Blean Forest), Harbledown and Rough Common (civil parish within Blean Forest) and Blean (civil parish within Blean Forest) — these are the Blean Forest pockets our drawings cover most. Heritage designations here include ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN ), BLEAN, CANTERBURY ( WHITSTABLE ROAD ) Registered 04.12.1996, CANTERBURY AND WHITSTABLE RAILWAY (HACKINGTON & BLEAN), HOTHE COURT and the Tyler Hill Conservation Area. Registered 27.03.1995. Canterbury City Council weighs each proposal against the adopted Canterbury local plan and Canterbury City Council's design guidance for householder work, where the 2,640 homes here are 17% 1983-1992, 16% 1930-1939, 14% 1955-1964, which is what sets the realistic roof and rear-projection options. On roofs the borough is trussed-rafter roofs typical of 1980s building and hipped roofs with shallow pitches typical of 1930s building, over 1980s estate houses (17% of 2,640 homes), 1930s semi-detached and detached houses (16%) and late-1950s and early-1960s houses (14%).
Heritage designation is the single biggest variable in Blean Forest, and it is address-specific: ALLCROFT GRANGE ( HACKINGTON ) (conservation area designated in 1995), AMERY COURT ( BLEAN ) (conservation area designated in 1995), BLEAN (conservation area designated in 1994), CANTERBURY ( WHITSTABLE ROAD ) Registered 04.12.1996 (conservation area designated in 1996), CANTERBURY AND WHITSTABLE RAILWAY (HACKINGTON & BLEAN) (conservation area designated in 1995), HOTHE COURT (conservation area designated in 1994) and the Tyler Hill Conservation Area. Registered 27.03.1995 (conservation area designated in 1995). Inside those boundaries permitted development is curtailed and Canterbury City 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, Blean Forest takes in Hackington, Harbledown and Rough Common and Blean. Canterbury City Council has 463 recorded Article 4 directions — check the address before assuming PD applies in Blean Forest.
On stock, Blean Forest is 1980s estate houses (17% of 2,640 homes), 1930s semi-detached and detached houses (16%) and late-1950s and early-1960s houses (14%) — which is why trussed-rafter roofs typical of 1980s building and hipped roofs with shallow pitches typical of 1930s building govern what a loft or rear projection can realistically be. Canterbury City Council decided 580 householder applications in the latest published year and granted 97%, with 43% issued inside the eight-week target. We work from the council's own published record.
The full build-period split for Blean Forest runs pre-1900 11% (280 homes), 1900-1918 2% (40 homes), 1919-1929 2% (60 homes), 1930-1939 16% (420 homes), 1945-1954 8% (200 homes), 1955-1964 14% (370 homes), 1965-1972 10% (260 homes), 1973-1982 7% (190 homes), 1983-1992 17% (440 homes), 1993-1999 5% (130 homes) and 2000-2008 5% (130 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.
Canterbury City Council also decides for Chestfield, Gorrell, Herne & Broomfield, Heron, St Stephen's, Westgate, Wincheap and Little Stour & Adisham, so a decision in Blean Forest 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 CHURCH COTTAGES, CHURCH LANE, NACKINGTON, 1 BOURNE COTTAGES, THE STREET, BISHOPSBOURNE, 1 BOX TREE COTTAGES, BOLTS HILL and 1 BUTTS COTTAGES, LOWER HARDRES. 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 Blean Forest and Canterbury City Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | Blean Forest |
|---|---|
| Dwellings recorded | 2,640 |
| Built pre-1900 | 280 (11%) |
| Built 1900-1918 | 40 (2%) |
| Built 1919-1929 | 60 (2%) |
| Built 1930-1939 | 420 (16%) |
| Built 1945-1954 | 200 (8%) |
| Built 1955-1964 | 370 (14%) |
| Built 1965-1972 | 260 (10%) |
| Built 1973-1982 | 190 (7%) |
| Built 1983-1992 | 440 (17%) |
| Built 1993-1999 | 130 (5%) |
| Built 2000-2008 | 130 (5%) |
| Built before 1919 | 12% |
| Built 1919–1939 | 18% |
| Built 1945–2008 | 65% |
| Conservation areas in Blean Forest | 7 (ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN )…) |
| Conservation areas district-wide | 98 |
| Article 4 directions recorded | 463 |
| Householder applications decided | 580 |
| Householder applications granted | 97% |
| Decided within 8 weeks | 43% |
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 Canterbury City Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
Blean Forest homes come in a handful of recurring shapes, and each one points to a different extension. The borough is built largely from 1980s estate houses (17% of 2,640 homes), 1930s semi-detached and detached houses (16%) and late-1950s and early-1960s houses (14%), 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. Canterbury City Council judges every one of them against the adopted Canterbury local plan and Canterbury City 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. Blean Forest contains ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN ), BLEAN conservation areas (ALLCROFT GRANGE ( HACKINGTON ) designated 1995), 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.
Blean Forest also protects whole streets — ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN ), BLEAN, CANTERBURY ( WHITSTABLE ROAD ) Registered 04.12.1996, CANTERBURY AND WHITSTABLE RAILWAY (HACKINGTON & BLEAN), HOTHE COURT and the Tyler Hill Conservation Area. Registered 27.03.1995 among them. Canterbury City Council has 463 recorded Article 4 directions — check the address before assuming PD applies in Blean Forest. 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 Blean Forest 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 Canterbury City Council if any of these apply:
We draw the footprint, the ridge and eaves heights and the neighbours' daylight on the page — the relationships Canterbury City 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 Canterbury City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Canterbury City Council granted 97% of its householder applications in the year to 31 March 2026, and ALLCROFT GRANGE ( HACKINGTON ) 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 ALLCROFT GRANGE ( HACKINGTON ), AMERY COURT ( BLEAN ) and BLEAN, 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 1980s estate houses (17% of 2,640 homes), a side-return infill frequently pairs with it to square off the plan; on wider late-1950s and early-1960s houses (14%), a two-storey side or rear extension can add a bedroom above without swallowing the garden.
The 2,640 homes here are 17% 1983-1992, 16% 1930-1939, 14% 1955-1964, 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 Canterbury City 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 Blean Forest projects come up most often:
Extension drawings for ALLCROFT GRANGE ( HACKINGTON )'s conservation area designated in 1995 — footprint-checked, daylight-tested and drawn to Canterbury City Council's guidance.
Extension drawings for AMERY COURT ( BLEAN )'s conservation area designated in 1995 — footprint-checked, daylight-tested and drawn to Canterbury City Council's guidance.
Extension drawings for BLEAN's conservation area designated in 1994 — footprint-checked, daylight-tested and drawn to Canterbury City Council's guidance.
Extension drawings for CANTERBURY ( WHITSTABLE ROAD ) Registered 04.12.1996's conservation area designated in 1996 — footprint-checked, daylight-tested and drawn to Canterbury City Council's guidance.
Extension drawings for CANTERBURY AND WHITSTABLE RAILWAY (HACKINGTON & BLEAN)'s conservation area designated in 1995 — footprint-checked, daylight-tested and drawn to Canterbury City Council's guidance.
Extension drawings for HOTHE COURT's conservation area designated in 1994 — footprint-checked, daylight-tested and drawn to Canterbury City Council's guidance.
The right extension in Blean Forest 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 Canterbury City 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 ALLCROFT GRANGE ( HACKINGTON ) and AMERY COURT ( BLEAN ) and Article 4 directions can remove permitted-development rights.
A fixed process built around how Canterbury City Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.
Tell us your Blean Forest 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 Canterbury City 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 Canterbury City 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 Canterbury City 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 Blean Forest you will need to apply to Canterbury City 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 ALLCROFT GRANGE ( HACKINGTON ) and AMERY COURT ( BLEAN ).
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 Canterbury City Council and a neighbour-consultation period, and it does not apply on designated land such as Blean Forest'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 Canterbury City 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 Blean Forest address specifically.
A householder planning application in Blean Forest 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. Canterbury City 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 Canterbury City Council's building control or an approved inspector can sign the work off. This applies to your Blean Forest address specifically.
Every house and brief is different, so we price each Blean Forest extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Canterbury City 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.