
Single-storey, double-storey, rear and side extension drawings for Clandon & Horsley homes — measured to Guildford Borough Council's design guidance, delivered in days and revised free until your decision, with a free approval-odds check before you commit.
Guildford Borough Council granted 86% of the householder planning decisions it made in its latest published year — 1 point below the 87% England-wide householder average. Clandon & Horsley contains East Clandon, East Horsley, West Clandon conservation areas (East Clandon designated 1973), 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 Guildford Borough Council needs a full application. In conservation areas such as East Clandon, East Horsley and West Clandon those rights are removed, so we confirm your exact address before a line is drawn. A validated householder application in Clandon & Horsley is determined against an 8-week statutory target.
East Clandon (conservation area designated in 1973), East Horsley (conservation area designated in 1973), West Clandon (conservation area designated in 1973), West Horsley (conservation area designated in 1973), West Clandon (civil parish within Clandon & Horsley), West Horsley (civil parish within Clandon & Horsley), East Clandon (civil parish within Clandon & Horsley) and East Horsley (civil parish within Clandon & Horsley) — these are the Clandon & Horsley pockets our drawings cover most. Heritage designations here include East Clandon, East Horsley, West Clandon and West Horsley. Guildford Borough Council weighs each proposal against the adopted Guildford local plan and Guildford Borough Council's design guidance for householder work, where the 3,800 homes here are 22% 1930-1939, 14% 1955-1964, 13% 1945-1954, which is what sets the realistic roof and rear-projection options. On roofs the borough is hipped roofs with shallow pitches typical of 1930s building and shallow gabled roofs typical of that period's building, over 1930s semi-detached and detached houses (22% of 3,800 homes), late-1950s and early-1960s houses (14%) and early postwar houses (13%).
Heritage designation is the single biggest variable in Clandon & Horsley, and it is address-specific: East Clandon (conservation area designated in 1973), East Horsley (conservation area designated in 1973), West Clandon (conservation area designated in 1973) and West Horsley (conservation area designated in 1973). Inside those boundaries permitted development is curtailed and Guildford 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, Clandon & Horsley takes in West Clandon, West Horsley, East Clandon and East Horsley. No Article 4 direction is recorded for Guildford Borough Council, but Clandon & Horsley's 4 conservation areas still limit permitted development on those streets.
On stock, Clandon & Horsley is 1930s semi-detached and detached houses (22% of 3,800 homes), late-1950s and early-1960s houses (14%) and early postwar houses (13%) — which is why hipped roofs with shallow pitches typical of 1930s building and shallow gabled roofs typical of that period's building govern what a loft or rear projection can realistically be. Guildford Borough Council decided 828 householder applications in the latest published year and granted 86%, with 31% issued inside the eight-week target. We work from the council's own published record.
The full build-period split for Clandon & Horsley runs pre-1900 8% (320 homes), 1900-1918 2% (80 homes), 1919-1929 7% (260 homes), 1930-1939 22% (830 homes), 1945-1954 13% (510 homes), 1955-1964 14% (540 homes), 1965-1972 6% (210 homes), 1973-1982 5% (200 homes), 1983-1992 3% (120 homes), 1993-1999 2% (80 homes) and 2000-2008 5% (200 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.
Guildford Borough Council also decides for Ash Vale, Castle, Normandy & Pirbright, Pilgrims, Send & Lovelace, Shalford, Stoke and Tillingbourne, so a decision in Clandon & Horsley 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.
Published figures for Clandon & Horsley and Guildford 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 | Clandon & Horsley |
|---|---|
| Dwellings recorded | 3,800 |
| Built pre-1900 | 320 (8%) |
| Built 1900-1918 | 80 (2%) |
| Built 1919-1929 | 260 (7%) |
| Built 1930-1939 | 830 (22%) |
| Built 1945-1954 | 510 (13%) |
| Built 1955-1964 | 540 (14%) |
| Built 1965-1972 | 210 (6%) |
| Built 1973-1982 | 200 (5%) |
| Built 1983-1992 | 120 (3%) |
| Built 1993-1999 | 80 (2%) |
| Built 2000-2008 | 200 (5%) |
| Built before 1919 | 11% |
| Built 1919–1939 | 29% |
| Built 1945–2008 | 49% |
| Conservation areas in Clandon & Horsley | 4 (East Clandon, East Horsley…) |
| Conservation areas district-wide | 41 |
| Article 4 directions recorded | 0 |
| Householder applications decided | 828 |
| Householder applications granted | 86% |
| Decided within 8 weeks | 31% |
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 Guildford Borough Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
Clandon & Horsley homes come in a handful of recurring shapes, and each one points to a different extension. The borough is built largely from 1930s semi-detached and detached houses (22% of 3,800 homes), late-1950s and early-1960s houses (14%) and early postwar houses (13%), 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. Guildford Borough Council judges every one of them against the adopted Guildford local plan and Guildford Borough 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. Clandon & Horsley contains East Clandon, East Horsley, West Clandon conservation areas (East Clandon designated 1973), 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.
Clandon & Horsley also protects whole streets — East Clandon, East Horsley, West Clandon and West Horsley among them. No Article 4 direction is recorded for Guildford Borough Council, but Clandon & Horsley's 4 conservation areas 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.

Plenty of Clandon & Horsley 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 Guildford Borough Council if any of these apply:
We draw the footprint, the ridge and eaves heights and the neighbours' daylight on the page — the relationships Guildford Borough 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 Guildford Borough Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Guildford Borough Council granted 86% of its householder applications in the year to 31 March 2026, and East Clandon 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 East Clandon, East Horsley and West Clandon, 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 1930s semi-detached and detached houses (22% of 3,800 homes), a side-return infill frequently pairs with it to square off the plan; on wider early postwar houses (13%), a two-storey side or rear extension can add a bedroom above without swallowing the garden.
The 3,800 homes here are 22% 1930-1939, 14% 1955-1964, 13% 1945-1954, 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 Guildford 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.

We draw extensions on every street in the borough. A few of the neighbourhoods where Clandon & Horsley projects come up most often:
Extension drawings for East Clandon's conservation area designated in 1973 — footprint-checked, daylight-tested and drawn to Guildford Borough Council's guidance.
Extension drawings for East Horsley's conservation area designated in 1973 — footprint-checked, daylight-tested and drawn to Guildford Borough Council's guidance.
Extension drawings for West Clandon's conservation area designated in 1973 — footprint-checked, daylight-tested and drawn to Guildford Borough Council's guidance.
Extension drawings for West Horsley's conservation area designated in 1973 — footprint-checked, daylight-tested and drawn to Guildford Borough Council's guidance.
Extension drawings for West Clandon's civil parish within Clandon & Horsley — footprint-checked, daylight-tested and drawn to Guildford Borough Council's guidance.
Extension drawings for West Horsley's civil parish within Clandon & Horsley — footprint-checked, daylight-tested and drawn to Guildford Borough Council's guidance.
The right extension in Clandon & Horsley 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 Guildford Borough 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 East Clandon and East Horsley and Article 4 directions can remove permitted-development rights.
A fixed process built around how Guildford Borough Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.
Tell us your Clandon & Horsley 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 Guildford Borough 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 Guildford Borough 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 Guildford Borough 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 Clandon & Horsley you will need to apply to Guildford 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 East Clandon and East Horsley.
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 Guildford Borough Council and a neighbour-consultation period, and it does not apply on designated land such as Clandon & Horsley'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 Guildford 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 Clandon & Horsley address specifically.
A householder planning application in Clandon & Horsley 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. Guildford Borough 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 Guildford Borough Council's building control or an approved inspector can sign the work off. This applies to your Clandon & Horsley address specifically.
Every house and brief is different, so we price each Clandon & Horsley extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Guildford 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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Same fixed quotes, same fast drawings — wherever your project is.