Annexe and granny-flat drawings for Ermin homes — designed to stay ancillary to the main house rather than become a separate dwelling, drawn to Cotswold District Council's policies, delivered in days and revised free until your decision.
Cotswold District Council granted 92% of the householder planning decisions it made in its latest published year — 5 points above the 87% England-wide householder average. Ermin contains Brimpsfield Conservation Area, Caudle Green Conservation Area, Coberley Conservation Area conservation areas (Brimpsfield Conservation Area designated 1989), 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.
The permitted-development ceilings are fixed: 40m³ of new roof volume for a terraced loft and 50m³ for a semi or detached house under Class B, plus a 3m single-storey rear extension on a terrace or 4m on a detached house under Class A. Ermin carries at least one Article 4 direction, and conservation areas including Brimpsfield Conservation Area, Caudle Green Conservation Area and Coberley Conservation Area remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Ermin is determined against an 8-week statutory target.
Brimpsfield (conservation area designated in 1989), Caudle Green (conservation area designated in 1989), Coberley (conservation area designated in 1992), Cowley (conservation area designated in 1991), Daglingworth (conservation area designated in 1984), Duntisbourne Abbots/Duntisbourne Leer (conservation area designated in 1984), Duntisbourne Rouse/Middle (conservation area designated in 1984), Edgeworth (conservation area designated in 1988), Elkstone (conservation area designated in 1989), Frampton Mansell (conservation area designated in 1982), Sapperton (conservation area designated in 1982), Syde (conservation area designated in 1989), Winstone (conservation area designated in 1988), Winstone (civil parish within Ermin), Sapperton (civil parish within Ermin), Syde (civil parish within Ermin), Daglingworth (civil parish within Ermin), Duntisbourne Abbots (civil parish within Ermin) and Duntisbourne Rouse (civil parish within Ermin) — these are the Ermin pockets our drawings cover most. Heritage designations here include Brimpsfield Conservation Area, Caudle Green Conservation Area, Coberley Conservation Area, Cowley Conservation Area, Daglingworth Conservation Area, Duntisbourne Abbots/Duntisbourne Leer Conservation Area, Duntisbourne Rouse/Middle Conservation Area, Edgeworth Conservation Area, Elkstone Conservation Area, Frampton Mansell Conservation Area, Sapperton Conservation Area, Syde Conservation Area and Winstone Conservation Area. Cotswold District Council weighs each proposal against Cotswold District Council's development plan and the design policies it applies to householder applications, where the 870 homes here are 51% pre-1900, 7% 1965-1972, 7% 1983-1992, 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 (51% of 870 homes), late-1960s and early-1970s houses (7%) and 1980s estate houses (7%).
Before anything is drawn we check your address against the designations that apply in Ermin: Brimpsfield (conservation area designated in 1989), Caudle Green (conservation area designated in 1989), Coberley (conservation area designated in 1992), Cowley (conservation area designated in 1991), Daglingworth (conservation area designated in 1984), Duntisbourne Abbots/Duntisbourne Leer (conservation area designated in 1984), Duntisbourne Rouse/Middle (conservation area designated in 1984), Edgeworth (conservation area designated in 1988), Elkstone (conservation area designated in 1989), Frampton Mansell (conservation area designated in 1982), Sapperton (conservation area designated in 1982), Syde (conservation area designated in 1989) and Winstone (conservation area designated in 1988). Inside those boundaries permitted development is curtailed and Cotswold 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, Ermin takes in Winstone, Sapperton, Syde, Daglingworth, Duntisbourne Abbots and Duntisbourne Rouse. Cotswold District Council has 22 recorded Article 4 directions, removing permitted development for rear and side extensions and roof enlargements such as dormers — check the address before assuming PD applies in Ermin.
On stock, Ermin is Victorian and earlier houses (51% of 870 homes), late-1960s and early-1970s houses (7%) and 1980s estate houses (7%) — 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. Cotswold District Council decided 592 householder applications in the latest published year and granted 92%, with 53% issued inside the eight-week target. That decision record, not a national figure, is what we design to.
The full build-period split for Ermin runs pre-1900 51% (440 homes), 1900-1918 1% (10 homes), 1919-1929 2% (20 homes), 1930-1939 1% (10 homes), 1945-1954 3% (30 homes), 1955-1964 2% (20 homes), 1965-1972 7% (60 homes), 1973-1982 5% (40 homes), 1983-1992 7% (60 homes), 1993-1999 6% (50 homes) and 2000-2008 5% (40 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.
Cotswold District Council also decides for Abbey, Blockley, Bourton Vale, Bourton Village, Campden & Vale, Fairford North, Fosseridge and Kemble, so a decision in Ermin 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 Article 4 (2) Direction Avening, Article 4 (2) Direction Bibury, Article 4 (2) Direction Blockley and Article 4 (2) Direction Bourton-On-The-Water. 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.
Published figures for Ermin and Cotswold 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 | Ermin |
|---|---|
| Dwellings recorded | 870 |
| Built pre-1900 | 440 (51%) |
| Built 1900-1918 | 10 (1%) |
| Built 1919-1929 | 20 (2%) |
| Built 1930-1939 | 10 (1%) |
| Built 1945-1954 | 30 (3%) |
| Built 1955-1964 | 20 (2%) |
| Built 1965-1972 | 60 (7%) |
| Built 1973-1982 | 40 (5%) |
| Built 1983-1992 | 60 (7%) |
| Built 1993-1999 | 50 (6%) |
| Built 2000-2008 | 40 (5%) |
| Built before 1919 | 52% |
| Built 1919–1939 | 3% |
| Built 1945–2008 | 34% |
| Conservation areas in Ermin | 13 (Brimpsfield Conservation Area, Caudle Green Conservation Area…) |
| Conservation areas district-wide | 144 |
| Article 4 directions recorded | 22 |
| Householder applications decided | 592 |
| Householder applications granted | 92% |
| Decided within 8 weeks | 53% |
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 Cotswold District Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
Councils do not decide annexes on square metres. They decide whether, once built, the accommodation forms part of one planning unit with the main house or a second one beside it. Cotswold District Council looks at whether the garden is shared or divided, whether the annexe has its own street access and address, whether the occupier could live there entirely independently, and whether the two households would function as one. That is the whole case, and it is made or lost on the layout.
Ermin is largely Victorian and earlier houses (51% of 870 homes), late-1960s and early-1970s houses (7%) and 1980s estate houses (7%), which shapes the realistic options: converting part of the existing house, extending it, or building a detached unit in the garden. A detached annexe can sometimes sit under Class E as an outbuilding incidental to the enjoyment of the dwellinghouse — but sleeping accommodation is generally not "incidental", so a garden annexe with a bedroom usually needs its own permission rather than relying on outbuilding rights.
In Ermin's conservation areas — including Brimpsfield Conservation Area and Caudle Green Conservation Area — a garden building is also judged on its effect on the character of the area, which limits height and footprint before the use question is reached. Cotswold District Council has 22 recorded Article 4 directions, removing permitted development for rear and side extensions and roof enlargements such as dormers — check the address before assuming PD applies in Ermin.
An annexe almost always needs an application to Cotswold District Council. Expect one where any of these apply:
We plan the annexe so its relationship to the main house is visible on the page — shared garden, connected access, a layout that reads as one household — and set out the case Cotswold District Council has to test, rather than leaving the officer to assume the worst.
Below is Cotswold District Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Cotswold District Council granted 92% of its householder applications in the year to 31 March 2026, and Brimpsfield Conservation Area shapes what is approved here. Annexe applications are decided on use as much as design, so the supporting case matters as much as the elevations.
Source: MHCLG planning application statistics (householder decisions, England, 1 April 2025 - 31 March 2026). Compare every borough on our London approval-rate league table.
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Across Brimpsfield, Caudle Green and Coberley, the annexes that succeed keep one shared garden, take access past the main house rather than from the street, and are modest against the host building — single storey where the plot is overlooked, and set back from boundaries. On victorian and earlier houses (51% of 870 homes), converting an integral garage or a rear ground floor is often approved more readily than a detached garden unit, because the ancillary relationship is self-evident.
Ermin contains Brimpsfield Conservation Area, Caudle Green Conservation Area, Coberley Conservation Area conservation areas (Brimpsfield Conservation Area designated 1989), so materials, fenestration and roof form are assessed against the appraisal. Where Cotswold District Council grants permission, it commonly attaches a condition tying occupation of the annexe to the main dwelling. That condition is not a problem to be avoided — it is usually the mechanism that makes approval possible, and we draft the application on that basis rather than pretending the annexe is something it is not.
We draw annexes across Ermin. A few of the areas where multigenerational schemes come up most often:
Annexe and granny-flat drawings for Brimpsfield — conservation area designated in 1989 — planned to stay ancillary and drawn to Cotswold District Council's policies.
Annexe and granny-flat drawings for Caudle Green — conservation area designated in 1989 — planned to stay ancillary and drawn to Cotswold District Council's policies.
Annexe and granny-flat drawings for Coberley — conservation area designated in 1992 — planned to stay ancillary and drawn to Cotswold District Council's policies.
Annexe and granny-flat drawings for Cowley — conservation area designated in 1991 — planned to stay ancillary and drawn to Cotswold District Council's policies.
Annexe and granny-flat drawings for Daglingworth — conservation area designated in 1984 — planned to stay ancillary and drawn to Cotswold District Council's policies.
Annexe and granny-flat drawings for Duntisbourne Abbots/Duntisbourne Leer — conservation area designated in 1984 — planned to stay ancillary and drawn to Cotswold District Council's policies.
Three similar buildings, three different consents. This is what separates them.
| What you build | Planning status | Key test | What Cotswold District Council checks |
|---|---|---|---|
| Garden room, no sleeping space | Often Class E permitted development | Incidental to the house | Height, footprint, boundary position |
| Annexe used by the household | Full application, usually with a tie condition | Ancillary use | Shared garden and access, layout |
| Self-contained unit, own access | New dwelling — full application | Separate planning unit | Policy on new homes, amenity, parking |
| Converted garage or ground floor | Often permitted, use still assessed | Whether use changes | Independence of the accommodation |
| Annexe on designated land | Full application | Designation | Character and appearance |
The ancillary/separate-dwelling distinction comes from section 55 of the Town and Country Planning Act 1990; outbuilding limits from the GPDO 2015, Schedule 2, Part 1, Class E.
A fixed process built around how Cotswold District Council tests the use question as well as the design.
Tell us who the annexe is for and where it would sit on the plot. We confirm designation status and tell you honestly whether the scheme reads as ancillary or as a separate dwelling in Ermin.
We measure the plot, the existing house and the access route, so the shared-garden and shared-access case can be drawn rather than asserted.
Chartered designers develop the annexe to your brief, with the layout, access and garden relationship arranged to support the ancillary case under Cotswold District Council's policies.
We submit the application with a supporting statement on use, manage validation and case-officer queries, and revise free until Cotswold District Council decides.
Almost always. Sleeping accommodation is generally not "incidental" to the enjoyment of a house, so it falls outside the outbuilding permitted-development right, and any annexe that could function independently raises a change-of-use question under section 55. In Ermin we prepare a full application to Cotswold District Council and make the ancillary case explicitly rather than hoping it is not asked.
A shared garden rather than a divided one, access through the main property rather than a separate street entrance, occupation by a member of the same household, and a physical and functional relationship with the main house. Cotswold District Council weighs those together — no single feature decides it, but a separate front door and a fenced-off garden together usually settle it against you. This applies to your Ermin address specifically.
Yes, subject to permission. A detached garden annexe is assessed on its scale against the plot, its effect on neighbours and the character of the area, and then on the use question. Keeping it single storey, set in from boundaries and served off the shared garden gives it the best prospect in Ermin, particularly near designated areas such as Brimpsfield Conservation Area and Caudle Green Conservation Area. Cotswold District Council is the decision-maker.
Commonly, yes — a condition tying occupation of the annexe to the main dwelling, so it cannot be sold or let separately. That is normally what makes approval possible, because it removes the concern that a new independent home is being created without going through housing policy. The condition runs with the land, so it matters at resale, and we explain the implications before you commit. This applies to your Ermin address specifically. Cotswold District Council is the decision-maker.
Yes. A new annexe is new habitable accommodation, so structure, fire escape, insulation and ventilation all apply, and a detached annexe close to a boundary raises fire-spread requirements as well. Planning and building control are separate consents with separate submissions — we prepare both so the approved design is the one that can actually be built. This applies to your Ermin address specifically. Cotswold District Council is the decision-maker.
A householder application runs to an eight-week statutory target; where the council treats the annexe as creating a new unit it becomes a minor application with a thirteen-week target instead. Which route applies depends on how the use is characterised, which is precisely why the ancillary case is worth making properly at the outset. This applies to your Ermin address specifically. Cotswold District Council is the decision-maker.
We quote each Ermin annexe individually, because plot, access and whether you are converting or building new all change the work, and send a fixed, no-obligation quote within one working day. It covers the full drawing pack and supporting statement, with free revisions until Cotswold District Council approves. Call 020 7864 7245 to start.
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