Annexe and granny-flat drawings for South Cambridgeshire homes — designed to stay ancillary to the main house rather than become a separate dwelling, drawn to South Cambridgeshire District Council's policies, delivered in days and revised free until your decision.
South Cambridgeshire District Council granted 95% of the householder planning decisions it made in its latest published year — 8 points above the 87% England-wide householder average. South Cambridgeshire contains Abington Pigotts - High Street, Abington Pigotts - St Michael's, Babraham conservation areas (Abington Pigotts - High Street 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. South Cambridgeshire carries at least one Article 4 direction, and conservation areas including Abington Pigotts - High Street, Abington Pigotts - St Michael's and Babraham remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in South Cambridgeshire is determined against an 8-week statutory target.
Abington Pigotts - High Street (conservation area designated in 1973), Abington Pigotts - St Michael's (conservation area designated in 1973), Babraham (conservation area designated in 1979), Baits Bite Lock (conservation area designated in 2006), Balsham - Village Centre (conservation area designated in 1995), Balsham - West End (conservation area designated in 1995), Barrington (conservation area designated in 2022), Bartlow (conservation area designated in 1978), Balsham (ward of South Cambridgeshire), Barrington (ward of South Cambridgeshire), Bassingbourn (ward of South Cambridgeshire), Caldecote (ward of South Cambridgeshire), Cottenham (ward of South Cambridgeshire), Fen Ditton & Fulbourn (ward of South Cambridgeshire), Foxton (ward of South Cambridgeshire) and Girton (ward of South Cambridgeshire) — these are the South Cambridgeshire pockets our drawings cover most. Heritage designations here include Abington Pigotts - High Street, Abington Pigotts - St Michael's, Babraham, Baits Bite Lock, Balsham - Village Centre, Balsham - West End, Barrington and Bartlow. South Cambridgeshire District Council weighs each proposal against South Cambridgeshire District Council's adopted local plan and its householder design guidance, where the 61,900 homes here are 8% 1973-1982, 7% pre-1900, 7% 1965-1972, which is what sets the realistic roof and rear-projection options. On roofs the borough is shallow trussed roofs typical of 1970s building and steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building, over 1970s and early-1980s houses (8% of 61,900 homes), Victorian and earlier houses (7%) and late-1960s and early-1970s houses (7%).
What is permitted in South Cambridgeshire turns on designation first, so that is where we start: Abington Pigotts - High Street (conservation area designated in 1973), Abington Pigotts - St Michael's (conservation area designated in 1973), Babraham (conservation area designated in 1979), Baits Bite Lock (conservation area designated in 2006), Balsham - Village Centre (conservation area designated in 1995), Balsham - West End (conservation area designated in 1995), Barrington (conservation area designated in 2022) and Bartlow (conservation area designated in 1978). Inside those boundaries permitted development is curtailed and South Cambridgeshire 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, South Cambridgeshire takes in Balsham, Barrington, Bassingbourn, Caldecote, Cottenham, Fen Ditton & Fulbourn, Foxton and Girton. South Cambridgeshire District Council has 8 recorded Article 4 directions, removing permitted development for painting the exterior — check the address before assuming PD applies in the district.
On stock, South Cambridgeshire is 1970s and early-1980s houses (8% of 61,900 homes), Victorian and earlier houses (7%) and late-1960s and early-1970s houses (7%) — which is why shallow trussed roofs typical of 1970s building and steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building govern what a loft or rear projection can realistically be. South Cambridgeshire District Council decided 787 householder applications in the latest published year and granted 95%, with 84% issued inside the eight-week target. We draw to that record rather than to a national average.
The full build-period split for South Cambridgeshire runs pre-1900 3% (190 homes), 1900-1918 0% (30 homes), 1919-1929 0% (10 homes), 1930-1939 6% (350 homes), 1945-1954 3% (170 homes), 1955-1964 30% (1,850 homes), 1965-1972 33% (1,990 homes), 1973-1982 4% (260 homes), 1983-1992 5% (310 homes), 1993-1999 4% (220 homes) and 2000-2008 3% (170 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.
South Cambridgeshire District Council also decides for Balsham, Barrington, Bassingbourn, Caldecote, Cottenham, Fen Ditton & Fulbourn, Foxton and Girton, so a decision in South Cambridgeshire 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 Beach Road Cottenham, Clay Close Lane, Impington, Land Adjacent To Villa Road Impington and Land Opp. Milestone Farm, Great Chishill. 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 South Cambridgeshire and South Cambridgeshire 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 | South Cambridgeshire |
|---|---|
| Dwellings recorded | 61,900 |
| Built pre-1900 | 190 (3%) |
| Built 1900-1918 | 30 (0%) |
| Built 1919-1929 | 10 (0%) |
| Built 1930-1939 | 350 (6%) |
| Built 1945-1954 | 170 (3%) |
| Built 1955-1964 | 1,850 (30%) |
| Built 1965-1972 | 1,990 (33%) |
| Built 1973-1982 | 260 (4%) |
| Built 1983-1992 | 310 (5%) |
| Built 1993-1999 | 220 (4%) |
| Built 2000-2008 | 170 (3%) |
| Built before 1919 | 12% |
| Built 1919–1939 | 7% |
| Built 1945–2008 | 61% |
| Conservation areas in South Cambridgeshire | 8 (Abington Pigotts - High Street, Abington Pigotts - St Michael's…) |
| Conservation areas district-wide | 85 |
| Article 4 directions recorded | 8 |
| Householder applications decided | 787 |
| Householder applications granted | 95% |
| Decided within 8 weeks | 84% |
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 South Cambridgeshire 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. South Cambridgeshire 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.
South Cambridgeshire is largely 1970s and early-1980s houses (8% of 61,900 homes), Victorian and earlier houses (7%) and late-1960s and early-1970s 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 South Cambridgeshire's conservation areas — including Abington Pigotts - High Street and Abington Pigotts - St Michael's — 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. South Cambridgeshire District Council has 8 recorded Article 4 directions, removing permitted development for painting the exterior — check the address before assuming PD applies in the district.
An annexe almost always needs an application to South Cambridgeshire 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 South Cambridgeshire District Council has to test, rather than leaving the officer to assume the worst.
Below is South Cambridgeshire District Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. South Cambridgeshire District Council granted 95% of 787 householder decisions in the year to 31 March 2026, 84% of them inside eight weeks. 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 Abington Pigotts - High Street, Abington Pigotts - St Michael's and Babraham, 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 1970s and early-1980s houses (8% of 61,900 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.
South Cambridgeshire contains Abington Pigotts - High Street, Abington Pigotts - St Michael's, Babraham conservation areas (Abington Pigotts - High Street designated 1973), so materials, fenestration and roof form are assessed against the appraisal. Where South Cambridgeshire 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 South Cambridgeshire. A few of the areas where multigenerational schemes come up most often:
Annexe and granny-flat drawings for Abington Pigotts - High Street — conservation area designated in 1973 — planned to stay ancillary and drawn to South Cambridgeshire District Council's policies.
Annexe and granny-flat drawings for Abington Pigotts - St Michael's — conservation area designated in 1973 — planned to stay ancillary and drawn to South Cambridgeshire District Council's policies.
Annexe and granny-flat drawings for Babraham — conservation area designated in 1979 — planned to stay ancillary and drawn to South Cambridgeshire District Council's policies.
Annexe and granny-flat drawings for Baits Bite Lock — conservation area designated in 2006 — planned to stay ancillary and drawn to South Cambridgeshire District Council's policies.
Annexe and granny-flat drawings for Balsham - Village Centre — conservation area designated in 1995 — planned to stay ancillary and drawn to South Cambridgeshire District Council's policies.
Annexe and granny-flat drawings for Balsham - West End — conservation area designated in 1995 — planned to stay ancillary and drawn to South Cambridgeshire District Council's policies.
Three similar buildings, three different consents. This is what separates them.
| What you build | Planning status | Key test | What South Cambridgeshire 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 South Cambridgeshire 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 South Cambridgeshire.
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 South Cambridgeshire District Council's policies.
We submit the application with a supporting statement on use, manage validation and case-officer queries, and revise free until South Cambridgeshire 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 South Cambridgeshire we prepare a full application to South Cambridgeshire 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. South Cambridgeshire 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.
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 South Cambridgeshire, particularly near designated areas such as Abington Pigotts - High Street and Abington Pigotts - St Michael's. South Cambridgeshire 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 South Cambridgeshire address specifically. South Cambridgeshire 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 South Cambridgeshire address specifically. South Cambridgeshire 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 South Cambridgeshire address specifically. South Cambridgeshire District Council is the decision-maker.
We quote each South Cambridgeshire 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 South Cambridgeshire District Council approves. Call 020 7864 7245 to start.
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