
Rear dormer drawings for Ottery St Mary roofs — the box across the back slope that turns a low attic into a full-height room, drawn to East Devon District Council's guidance and the volume limits, delivered in days and revised free until your decision, with a free approval-odds check first.
East Devon District Council granted 94% of the householder planning decisions it made in its latest published year — 7 points above the 87% England-wide householder average. Ottery St Mary contains the Ottery St Mary conservation area (Ottery St Mary 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 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. In conservation areas such as Ottery St Mary those rights are removed, so we confirm your exact address before a line is drawn. A validated householder application in Ottery St Mary is determined against an 8-week statutory target.
Ottery St Mary (conservation area designated in 1973) and Ottery St. Mary (civil parish within Ottery St Mary) — these are the Ottery St Mary pockets our drawings cover most. Heritage designations here include Ottery St Mary. East Devon District Council weighs each proposal against the adopted East Devon local plan and East Devon District Council's design guidance for householder work, where the 4,790 homes here are 21% pre-1900, 17% 1965-1972, 10% 1973-1982, 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 shallow-pitched roofs and integral garages typical of that period's building, over Victorian and earlier houses (21% of 4,790 homes), late-1960s and early-1970s houses (17%) and 1970s and early-1980s houses (10%).
What is permitted in Ottery St Mary turns on designation first, so that is where we start: Ottery St Mary (conservation area designated in 1973). Inside those boundaries permitted development is curtailed and East Devon District 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, Ottery St Mary takes in Ottery St. Mary. No Article 4 direction is recorded for East Devon District Council, but Ottery St Mary's 1 conservation area still limit permitted development on those streets.
On stock, Ottery St Mary is Victorian and earlier houses (21% of 4,790 homes), late-1960s and early-1970s houses (17%) and 1970s and early-1980s houses (10%) — which is why steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and shallow-pitched roofs and integral garages typical of that period's building govern what a loft or rear projection can realistically be. East Devon District Council decided 587 householder applications in the latest published year and granted 94%, with 72% issued inside the eight-week target. We draw to that record rather than to a national average.
The full build-period split for Ottery St Mary runs pre-1900 21% (990 homes), 1900-1918 1% (50 homes), 1919-1929 2% (110 homes), 1930-1939 1% (70 homes), 1945-1954 5% (230 homes), 1955-1964 5% (240 homes), 1965-1972 17% (830 homes), 1973-1982 10% (480 homes), 1983-1992 5% (240 homes), 1993-1999 5% (220 homes) and 2000-2008 7% (320 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.
East Devon District Council also decides for Axminster, Beer & Branscombe, Broadclyst, Budleigh & Raleigh, Clyst Valley, Coly Valley, Dunkeswell & Otterhead and Exe Valley, so a decision in Ottery St Mary 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 Ottery St Mary and East Devon District Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | Ottery St Mary |
|---|---|
| Dwellings recorded | 4,790 |
| Built pre-1900 | 990 (21%) |
| Built 1900-1918 | 50 (1%) |
| Built 1919-1929 | 110 (2%) |
| Built 1930-1939 | 70 (1%) |
| Built 1945-1954 | 230 (5%) |
| Built 1955-1964 | 240 (5%) |
| Built 1965-1972 | 830 (17%) |
| Built 1973-1982 | 480 (10%) |
| Built 1983-1992 | 240 (5%) |
| Built 1993-1999 | 220 (5%) |
| Built 2000-2008 | 320 (7%) |
| Built before 1919 | 22% |
| Built 1919–1939 | 4% |
| Built 1945–2008 | 53% |
| Conservation areas in Ottery St Mary | 1 (Ottery St Mary) |
| Conservation areas district-wide | 32 |
| Article 4 directions recorded | 0 |
| Householder applications decided | 587 |
| Householder applications granted | 94% |
| Decided within 8 weeks | 72% |
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 East Devon District 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 Ottery St Mary is built for it — the borough runs to Victorian and earlier houses (21% of 4,790 homes), late-1960s and early-1970s houses (17%) and 1970s and early-1980s houses (10%) under steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and shallow-pitched roofs and integral garages 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. East Devon District Council tests the dormer against the adopted East Devon local plan and East Devon District 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. Ottery St Mary contains the Ottery St Mary conservation area (Ottery St Mary 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 Ottery St Mary's streets are protected — Ottery St Mary 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 East Devon District Council, but Ottery St Mary's 1 conservation area still limit permitted development on those streets. We confirm the designation before the box is sized.

Many rear dormers in Ottery St Mary are permitted development, but the volume and position decide it. You will normally need a full application to East Devon District 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 East Devon District Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. East Devon District Council granted 94% of its householder applications in the year to 31 March 2026, and Ottery St Mary 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 Ottery St Mary and Ottery St. Mary, 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 steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building, this returns a full-height double and en-suite from what was standing-room-only, usually inside the permitted-development volume.
The 4,790 homes here are 21% pre-1900, 17% 1965-1972, 10% 1973-1982, 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 East Devon District 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 Ottery St Mary dormers come up most often:
Dormer loft drawings for Ottery St Mary's conservation area designated in 1973 — volume-checked, set-back-detailed and drawn to East Devon District Council's guidance.
Dormer loft drawings for Ottery St. Mary's civil parish within Ottery St Mary — volume-checked, set-back-detailed and drawn to East Devon District Council's guidance.
Whether a dormer in Ottery St Mary 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 East Devon District 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 Ottery St Mary, Class B dormer rights are removed and every dormer needs a full application.
A fixed process built around how East Devon District Council validates and decides dormer applications — most drawings are submission-ready within seven days of survey.
Send us your Ottery St Mary 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 East Devon District 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 East Devon District Council's roof-alteration guidance.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until East Devon District 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 Ottery St Mary you will need a full application to East Devon District Council for a front or side dormer, a box that exceeds the volume, and any dormer in a conservation area such as Ottery St Mary, 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 Ottery St Mary 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. East Devon District 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 East Devon District 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 Ottery St Mary 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 East Devon District 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 Ottery St Mary address specifically.
If your dormer is permitted development, a lawful development certificate from East Devon District 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 Ottery St Mary address specifically.
We price each Ottery St Mary 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 East Devon District 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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