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

House extension plans in St Andrews

Single-storey, double-storey, rear and side extension drawings for St Andrews homes — measured to Swindon Borough 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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St Andrews planning decisions and design rules

Swindon Borough Council granted 91% of the householder planning decisions it made in its latest published year — 4 points above the 87% England-wide householder average. St Andrews contains the Blunsdon St Andrew conservation area (Blunsdon St Andrew designated 1990), 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) 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. In conservation areas such as Blunsdon St Andrew those rights are removed, so we confirm your exact address before a line is drawn. A validated householder application in St Andrews is determined against an 8-week statutory target.

Blunsdon St Andrew (conservation area designated in 1990) and Haydon Wick (civil parish within St Andrews) — these are the St Andrews pockets our drawings cover most. Heritage designations here include Blunsdon St Andrew. Swindon Borough Council weighs each proposal against Swindon Borough Council's adopted local plan and its householder design guidance, where the 7,900 homes here are 39% 2000-2008, 12% 1993-1999, 1% 1930-1939, which is what sets the realistic roof and rear-projection options. On roofs the borough is trussed-rafter roofs typical of 2000s building and trussed-rafter roofs typical of 1990s building, over 2000s houses and apartments (39% of 7,900 homes), 1990s estate houses (12%) and 1930s semi-detached and detached houses (1%).

Why a St Andrews scheme is judged on St Andrews terms

What is permitted in St Andrews turns on designation first, so that is where we start: Blunsdon St Andrew (conservation area designated in 1990). Inside those boundaries permitted development is curtailed and Swindon 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, St Andrews takes in Haydon Wick. No Article 4 direction is recorded for Swindon Borough Council, but St Andrews's 1 conservation area still limit permitted development on those streets.

On stock, St Andrews is 2000s houses and apartments (39% of 7,900 homes), 1990s estate houses (12%) and 1930s semi-detached and detached houses (1%) — which is why trussed-rafter roofs typical of 2000s building and trussed-rafter roofs typical of 1990s building govern what a loft or rear projection can realistically be. Swindon Borough Council decided 436 householder applications in the latest published year and granted 91%, with 92% issued inside the eight-week target. We draw to that record rather than to a national average.

The full build-period split for St Andrews runs pre-1900 0% (30 homes), 1930-1939 1% (50 homes), 1945-1954 0% (20 homes), 1955-1964 0% (10 homes), 1973-1982 1% (40 homes), 1993-1999 12% (970 homes) and 2000-2008 39% (3,110 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.

Swindon Borough Council also decides for Central, Chiseldon and Lawn, Eastcott, Mannington and Western, Old Town, Ridgeway, Rodbourne Cheney and Blunsdon and Highworth, so a decision in St Andrews 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.

St Andrews by the published data

Published figures for St Andrews and Swindon Borough Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.

MeasureSt Andrews
Dwellings recorded7,900
Built pre-190030 (0%)
Built 1930-193950 (1%)
Built 1945-195420 (0%)
Built 1955-196410 (0%)
Built 1973-198240 (1%)
Built 1993-1999970 (12%)
Built 2000-20083,110 (39%)
Built before 19190%
Built 1919–19391%
Built 1945–200853%
Conservation areas in St Andrews1 (Blunsdon St Andrew)
Conservation areas district-wide28
Article 4 directions recorded0
Householder applications decided436
Householder applications granted91%
Decided within 8 weeks92%

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 Swindon Borough Council's own, from MHCLG live table PS2 for the year to 31 March 2026.

Extension plans built around Swindon Borough Council's rules

St Andrews homes come in a handful of recurring shapes, and each one points to a different extension. The borough is built largely from 2000s houses and apartments (39% of 7,900 homes), 1990s estate houses (12%) and 1930s semi-detached and detached houses (1%), 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. Swindon Borough Council judges every one of them against Swindon Borough Council's adopted local plan and its householder design guidance, 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. St Andrews contains the Blunsdon St Andrew conservation area (Blunsdon St Andrew designated 1990), 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.

St Andrews also protects whole streets — Blunsdon St Andrew among them. No Article 4 direction is recorded for Swindon Borough Council, but St Andrews's 1 conservation area still limit permitted development on those streets. 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 St Andrews home

Do I need planning permission to extend my house in St Andrews?

Plenty of St Andrews 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 Swindon Borough 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 Blunsdon St Andrew, where the larger-home route and side extensions are not permitted development

St Andrews extension approval rates — live from council data

Below is Swindon Borough Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Swindon Borough Council granted 91% of its householder applications in the year to 31 March 2026, and Blunsdon St Andrew 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.

91%householder applications approved in Swindon
87%national average — Swindon is 4 points above the national average

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Which extensions get approved in St Andrews

Across Blunsdon St Andrew and Haydon Wick, 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 2000s houses and apartments (39% of 7,900 homes), a side-return infill frequently pairs with it to square off the plan; on wider 1930s semi-detached and detached houses (1%), a two-storey side or rear extension can add a bedroom above without swallowing the garden.

The 7,900 homes here are 39% 2000-2008, 12% 1993-1999, 1% 1930-1939, 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 Swindon Borough 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 St Andrews house

House extensions across St Andrews

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

Blunsdon St Andrew

Extension drawings for Blunsdon St Andrew's conservation area designated in 1990 — footprint-checked, daylight-tested and drawn to Swindon Borough Council's guidance.

Haydon Wick

Extension drawings for Haydon Wick's civil parish within St Andrews — footprint-checked, daylight-tested and drawn to Swindon Borough Council's guidance.

Which extension suits your St Andrews home?

The right extension in St Andrews 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 Swindon Borough 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 Blunsdon St Andrew and Article 4 directions can remove permitted-development rights.

Four steps to an approved St Andrews extension

A fixed process built around how Swindon Borough 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 St Andrews 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 Swindon Borough 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 Swindon Borough 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 Swindon Borough Council issues its decision.

Frequently asked questions

Do I need planning permission to extend my house in St Andrews?

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 St Andrews you will need to apply to Swindon Borough 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 Blunsdon St Andrew.

How deep can a single-storey rear extension go in St Andrews 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 Swindon Borough Council and a neighbour-consultation period, and it does not apply on designated land such as St Andrews's conservation areas. We confirm which route your property qualifies for before drawing.

Can I build a double-storey extension in St Andrews?

Two-storey and double-storey extensions almost always need a full householder application to Swindon Borough 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 St Andrews address specifically.

How long does Swindon Borough Council take to decide an extension application?

A householder planning application in St Andrews 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. Swindon Borough Council is the decision-maker.

Will my extension in St Andrews 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 Swindon Borough Council's building control or an approved inspector can sign the work off. This applies to your St Andrews address specifically.

How much do extension plans in St Andrews cost?

Every house and brief is different, so we price each St Andrews extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Swindon Borough 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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