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House extension plans in Charminster St Mary's — a glazed single-storey rear extension on a period home
Charminster St Mary's · House Extension Drawings & Planning

House extension plans in Charminster St Mary's

Single-storey, double-storey, rear and side extension drawings for Charminster St Mary's 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.

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Charminster St Mary's planning decisions and design rules

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. Charminster St Mary's contains Bradford Peverell Conservation Area, Charlton Down / Charminster Herrison Conservation Area 1, Charlton Down / Charminster Herrison Conservation Area 2 conservation areas (Bradford Peverell Conservation Area designated 1993), 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. Charminster St Mary's carries at least one Article 4 direction, and conservation areas including Bradford Peverell Conservation Area, Charlton Down / Charminster Herrison Conservation Area 1 and Charlton Down / Charminster Herrison Conservation Area 2 remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Charminster St Mary's is determined against an 8-week statutory target.

Bradford Peverell (conservation area designated in 1993), Charlton Down / Charminster Herrison Conservation Area 1 (conservation area designated in 2012), Charlton Down / Charminster Herrison Conservation Area 2 (conservation area designated in 2012), Charlton Down / Charminster Herrison Conservation Area 3 (conservation area designated in 2012), Charminster Conservation Area 1 (conservation area designated in 1974), Charminster Conservation Area 2 (conservation area designated in 1990), Charminster Conservation Area 3 (conservation area designated in 1990), Charminster Conservation Area 4 (conservation area designated in 1991), Frampton (conservation area designated in 1976), Higher Kingston (conservation area designated in 1990), Stinsford (conservation area designated in 1990), Bradford Peverell (civil parish within Charminster St Mary's), Charminster (civil parish within Charminster St Mary's), Frampton (civil parish within Charminster St Mary's), Stinsford (civil parish within Charminster St Mary's) and Stratton (civil parish within Charminster St Mary's) — these are the Charminster St Mary's pockets our drawings cover most. Heritage designations here include Bradford Peverell Conservation Area, Charlton Down / Charminster Herrison Conservation Area 1, Charlton Down / Charminster Herrison Conservation Area 2, Charlton Down / Charminster Herrison Conservation Area 3, Charminster Conservation Area 1, Charminster Conservation Area 2, Charminster Conservation Area 3, Charminster Conservation Area 4, Frampton Conservation Area, Higher Kingston Conservation Area and Stinsford Conservation Area. Dorset Council weighs each proposal against Dorset Council's development plan and the design policies it applies to householder applications, where the 3,580 homes here are 29% pre-1900, 16% 2000-2008, 9% 1965-1972, 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 trussed-rafter roofs typical of 2000s building, over Victorian and earlier houses (29% of 3,580 homes), 2000s houses and apartments (16%) and late-1960s and early-1970s houses (9%).

Why a Charminster St Mary's scheme is judged on Charminster St Mary's terms

What is permitted in Charminster St Mary's turns on designation first, so that is where we start: Bradford Peverell (conservation area designated in 1993), Charlton Down / Charminster Herrison Conservation Area 1 (conservation area designated in 2012), Charlton Down / Charminster Herrison Conservation Area 2 (conservation area designated in 2012), Charlton Down / Charminster Herrison Conservation Area 3 (conservation area designated in 2012), Charminster Conservation Area 1 (conservation area designated in 1974), Charminster Conservation Area 2 (conservation area designated in 1990), Charminster Conservation Area 3 (conservation area designated in 1990), Charminster Conservation Area 4 (conservation area designated in 1991), Frampton (conservation area designated in 1976), Higher Kingston (conservation area designated in 1990) and Stinsford (conservation area designated in 1990). 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, Charminster St Mary's takes in Bradford Peverell, Charminster, Frampton, Stinsford and Stratton. Dorset Council has 77 recorded Article 4 directions — check the address before assuming PD applies in Charminster St Mary's.

On stock, Charminster St Mary's is Victorian and earlier houses (29% of 3,580 homes), 2000s houses and apartments (16%) and late-1960s and early-1970s houses (9%) — which is why steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and trussed-rafter roofs typical of 2000s 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. We draw to that record rather than to a national average.

The full build-period split for Charminster St Mary's runs pre-1900 29% (1,040 homes), 1900-1918 1% (30 homes), 1919-1929 1% (40 homes), 1930-1939 3% (90 homes), 1945-1954 3% (100 homes), 1955-1964 9% (310 homes), 1965-1972 9% (340 homes), 1973-1982 8% (270 homes), 1983-1992 6% (230 homes), 1993-1999 6% (220 homes) and 2000-2008 16% (560 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, Chickerell, Cranborne & Alderholt and Cranborne Chase, so a decision in Charminster St Mary's 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.

Charminster St Mary's by the published data

Published figures for Charminster St Mary's 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.

MeasureCharminster St Mary's
Dwellings recorded3,580
Built pre-19001,040 (29%)
Built 1900-191830 (1%)
Built 1919-192940 (1%)
Built 1930-193990 (3%)
Built 1945-1954100 (3%)
Built 1955-1964310 (9%)
Built 1965-1972340 (9%)
Built 1973-1982270 (8%)
Built 1983-1992230 (6%)
Built 1993-1999220 (6%)
Built 2000-2008560 (16%)
Built before 191930%
Built 1919–19394%
Built 1945–200857%
Conservation areas in Charminster St Mary's11 (Bradford Peverell Conservation Area, Charlton Down / Charminster Herrison Conservation Area 1…)
Conservation areas district-wide311
Article 4 directions recorded77
Householder applications decided1,261
Householder applications granted95%
Decided within 8 weeks78%

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.

Extension plans built around Dorset Council's rules

Charminster St Mary's 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 (29% of 3,580 homes), 2000s houses and apartments (16%) and late-1960s and early-1970s 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 Dorset Council's development plan and the design policies it applies to householder applications, 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. Charminster St Mary's contains Bradford Peverell Conservation Area, Charlton Down / Charminster Herrison Conservation Area 1, Charlton Down / Charminster Herrison Conservation Area 2 conservation areas (Bradford Peverell Conservation Area designated 1993), 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.

Charminster St Mary's also protects whole streets — Bradford Peverell Conservation Area, Charlton Down / Charminster Herrison Conservation Area 1, Charlton Down / Charminster Herrison Conservation Area 2, Charlton Down / Charminster Herrison Conservation Area 3, Charminster Conservation Area 1, Charminster Conservation Area 2, Charminster Conservation Area 3, Charminster Conservation Area 4, Frampton Conservation Area, Higher Kingston Conservation Area and Stinsford Conservation Area among them. Dorset Council has 77 recorded Article 4 directions — check the address before assuming PD applies in Charminster St Mary's. 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.

Isometric house extension drawing for a Charminster St Mary's home

Do I need planning permission to extend my house in Charminster St Mary's?

Plenty of Charminster St Mary's 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:

  • The single-storey rear extension is deeper than 3 metres on a terrace or semi, or 4 metres on a detached house (6m/8m needs prior approval under the larger-home scheme)
  • It is a two-storey or double-storey extension, or the rear extension is higher than 4 metres
  • A side extension is wider than half the original house, or more than one storey
  • Any part projects forward of the principal (front) elevation, or the extension covers more than half the garden
  • Your home is in a conservation area such as Bradford Peverell Conservation Area and Charlton Down / Charminster Herrison Conservation Area 1, where the larger-home route and side extensions are not permitted development
  • An Article 4 direction applies to your street — Charminster St Mary's has several, so this is checked first

Charminster St Mary's extension approval rates — live from council data

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 Bradford Peverell Conservation Area 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.

95%householder applications approved in Dorset
87%national average — Dorset is 8 points above the national average

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Which extensions get approved in Charminster St Mary's

Across Bradford Peverell, Charlton Down / Charminster Herrison Conservation Area 1 and Charlton Down / Charminster Herrison Conservation Area 2, 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 (29% of 3,580 homes), a side-return infill frequently pairs with it to square off the plan; on wider late-1960s and early-1970s houses (9%), a two-storey side or rear extension can add a bedroom above without swallowing the garden.

The 3,580 homes here are 29% pre-1900, 16% 2000-2008, 9% 1965-1972, 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.

Single-storey rear extension opening onto the garden of a Charminster St Mary's house

House extensions across Charminster St Mary's

We draw extensions on every street in the borough. A few of the neighbourhoods where Charminster St Mary's projects come up most often:

Bradford Peverell

Extension drawings for Bradford Peverell's conservation area designated in 1993 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.

Charlton Down / Charminster Herrison Conservation Area 1

Extension drawings for Charlton Down / Charminster Herrison Conservation Area 1's conservation area designated in 2012 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.

Charlton Down / Charminster Herrison Conservation Area 2

Extension drawings for Charlton Down / Charminster Herrison Conservation Area 2's conservation area designated in 2012 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.

Charlton Down / Charminster Herrison Conservation Area 3

Extension drawings for Charlton Down / Charminster Herrison Conservation Area 3's conservation area designated in 2012 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.

Charminster Conservation Area 1

Extension drawings for Charminster Conservation Area 1's conservation area designated in 1974 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.

Charminster Conservation Area 2

Extension drawings for Charminster Conservation Area 2's conservation area designated in 1990 — footprint-checked, daylight-tested and drawn to Dorset Council's guidance.

Which extension suits your Charminster St Mary's home?

The right extension in Charminster St Mary's 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 typePermitted development?What it addsWhat Dorset Council checks
Single-storey rearOften, within 3m/4m depth (6m/8m via prior approval)Bigger kitchen-diner across the backDepth, height, neighbour daylight (45°)
Side-return infillSometimes, if within width and height limitsSquares off an L-shaped ground floorWidth vs the original house, glazing to boundary
Two-storey rear/sideNo — full applicationExtra bedroom or bathroom aboveBulk, overlooking, 7m rear-boundary gap
Wraparound (rear + side)No — full applicationWhole-width open-plan ground floorCombined footprint and garden retained

Route depends on your street — conservation areas such as Bradford Peverell Conservation Area and Charlton Down / Charminster Herrison Conservation Area 1 and Article 4 directions can remove permitted-development rights.

Four steps to an approved Charminster St Mary's extension

A fixed process built around how Dorset Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.

  1. 1

    Free approval check

    Tell us your Charminster St Mary's 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.

  2. 2

    Measured survey

    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.

  3. 3

    Extension design & drawings

    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.

  4. 4

    Submission & follow-through

    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.

Frequently asked questions

Do I need planning permission to extend my house in Charminster St Mary's?

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 Charminster St Mary's 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 Bradford Peverell Conservation Area and Charlton Down / Charminster Herrison Conservation Area 1.

How deep can a single-storey rear extension go in Charminster St Mary's without planning permission?

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 Charminster St Mary's's conservation areas. We confirm which route your property qualifies for before drawing.

Can I build a double-storey extension in Charminster St Mary's?

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 Charminster St Mary's address specifically.

How long does Dorset Council take to decide an extension application?

A householder planning application in Charminster St Mary's 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.

Will my extension in Charminster St Mary's need building regulations approval as well as planning?

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 Charminster St Mary's address specifically.

How much do extension plans in Charminster St Mary's cost?

Every house and brief is different, so we price each Charminster St Mary's 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.

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