
Rear dormer drawings for Clandon & Horsley roofs — the box across the back slope that turns a low attic into a full-height room, drawn to Guildford Borough Council's guidance and the volume limits, delivered in days and revised free until your decision, with a free approval-odds check first.
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.
The box dormer is the workhorse loft, and most of Clandon & Horsley is built for it — the borough runs to 1930s semi-detached and detached houses (22% of 3,800 homes), late-1950s and early-1960s houses (14%) and early postwar houses (13%) under hipped roofs with shallow pitches typical of 1930s building and shallow gabled roofs typical of that period's building, and a flat-roofed box across the rear slope is the cheapest cubic metre of full-height space those roofs give up. Guildford Borough Council tests the dormer against the adopted Guildford local plan and Guildford Borough Council's design guidance for householder work, and because permitted development turns on a number, the volume you propose against the volume you have left is the first thing an officer or a certificate checks.
That is why the arithmetic goes on the drawings. We calculate the box against the 40- or 50-cubic-metre allowance, count any earlier roof enlargement into the total, hold the flat roof below the ridge and set the face back off the eaves so the dormer reads as subordinate. 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 the cheeks, the window line and the material are drawn to answer it rather than invite a query.
Where Clandon & Horsley's streets are protected — East Clandon, East Horsley, West Clandon and West Horsley among them — the Class B dormer right is switched off and even a modest rear box needs consent. No Article 4 direction is recorded for Guildford Borough Council, but Clandon & Horsley's 4 conservation areas still limit permitted development on those streets. We confirm the designation before the box is sized.

Many rear dormers in Clandon & Horsley are permitted development, but the volume and position decide it. You will normally need a full application to Guildford Borough Council if any of these apply:
We draw the box within its volume allowance, the flat roof below the ridge and the face set back off the eaves — the three things a dormer stands or falls on — and submit a validation-complete pack, whether that is a lawful development certificate 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 dormer is decided on volume and set-back, so a pack that shows the calculation and the eaves detail is cleared faster and refused less often than a DIY submission.
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 dormer that goes through is the subordinate rear box: flat roof kept low, cheeks clad to recede, side windows obscure-glazed against overlooking, and the whole thing set back so the original eaves line still reads from the garden. On hipped roofs with shallow pitches typical of 1930s building, this returns a full-height double and en-suite from what was standing-room-only, usually inside the permitted-development volume.
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 keep the box off the ridge, match the cheek material to the roof, and where the volume is already spent — or the street is designated — draw the dormer as a householder application composed to Guildford Borough Council's roof-alteration guidance rather than push a certificate that would be refused.

We draw rear dormers on the terraced and semi-detached streets across the borough. A few of the neighbourhoods where Clandon & Horsley dormers come up most often:
Dormer loft drawings for East Clandon's conservation area designated in 1973 — volume-checked, set-back-detailed and drawn to Guildford Borough Council's guidance.
Dormer loft drawings for East Horsley's conservation area designated in 1973 — volume-checked, set-back-detailed and drawn to Guildford Borough Council's guidance.
Dormer loft drawings for West Clandon's conservation area designated in 1973 — volume-checked, set-back-detailed and drawn to Guildford Borough Council's guidance.
Dormer loft drawings for West Horsley's conservation area designated in 1973 — volume-checked, set-back-detailed and drawn to Guildford Borough Council's guidance.
Dormer loft drawings for West Clandon's civil parish within Clandon & Horsley — volume-checked, set-back-detailed and drawn to Guildford Borough Council's guidance.
Dormer loft drawings for West Horsley's civil parish within Clandon & Horsley — volume-checked, set-back-detailed and drawn to Guildford Borough Council's guidance.
Whether a dormer in Clandon & Horsley needs permission comes down to where it sits and how big the box is. This is how the cases compare.
| Dormer type | Permitted development? | What it gains | What Guildford Borough Council checks |
|---|---|---|---|
| Rear box, within volume | Usually yes | Full-height room across the back | Volume total, 20cm eaves set-back |
| Rear box, over volume limit | No — full application | A larger room | How far over the allowance, bulk |
| Front or side dormer | No — full application | Light to the front rooms | Visibility from the street, character |
| Dormer in a conservation area | No — full application | Same space, extra scrutiny | Roof form and street appearance |
In conservation areas such as East Clandon and East Horsley, Class B dormer rights are removed and every dormer needs a full application.
A fixed process built around how Guildford Borough Council validates and decides dormer applications — most drawings are submission-ready within seven days of survey.
Send us your Clandon & Horsley postcode and roof type. We confirm your conservation and Article 4 status, work out how much permitted-development volume you have left, and score your odds against live Guildford Borough Council decisions.
We measure ridge and eaves heights, roof pitch and the existing loft floor — the numbers the volume calculation, the set-back and the head heights depend on.
Chartered designers develop the box to your brief, drawn inside the Class B volume limits or, where those are exhausted or removed, to Guildford Borough Council's roof-alteration guidance.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until Guildford Borough Council issues its decision.
Often not. A rear box dormer within 40 cubic metres on a terrace, or 50 on a semi or detached house, set back at least 20 centimetres from the eaves and kept below the ridge, is usually permitted development. In Clandon & Horsley you will need a full application to Guildford Borough Council for a front or side dormer, a box that exceeds the volume, and any dormer in a conservation area such as East Clandon and East Horsley, where those rights are removed.
The permitted-development limit is a volume, not a footprint: 40 cubic metres of added roof space on a terraced house and 50 on a semi-detached or detached one, and any earlier loft enlargement counts against that total. In Clandon & Horsley the box must also sit below the ridge and back from the eaves. We measure your roof and calculate the exact volume you have left before drawing. Guildford Borough Council is the decision-maker.
Not under permitted development. A dormer on the front roof slope, or one facing a highway, always needs a full application to Guildford Borough Council, because it changes how the house reads from the street. Rear box dormers are far more likely to be approved — or to be permitted development outright — which is why almost every Clandon & Horsley dormer we draw sits on the back slope.
Often, on a terrace or semi. If the dormer or the loft steelwork meets the party wall with your neighbour, the Party Wall etc. Act applies and notice must be served before work starts — separately from Guildford Borough Council's planning decision. We flag the party-wall junction on the drawings so a surveyor can be appointed early and the build is not held up. This applies to your Clandon & Horsley address specifically.
If your dormer is permitted development, a lawful development certificate from Guildford Borough Council is council-stamped proof of it — worth holding, because a buyer's solicitor will ask for it when you sell. We prepare and submit the certificate with the same measured drawing pack that shows the box within its volume allowance. This applies to your Clandon & Horsley address specifically.
We price each Clandon & Horsley dormer individually, because the roof pitch and the volume left vary house to house, and send a fixed, no-obligation quote within one working day. It covers the full drawing pack with free revisions until Guildford Borough Council approves, and we confirm at the outset whether your box is permitted development or needs an application. Call 020 7864 7245 to start.
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