Annexe and granny-flat drawings for Selly Oak homes — designed to stay ancillary to the main house rather than become a separate dwelling, drawn to Birmingham City Council's policies, delivered in days and revised free until your decision.
Birmingham City Council granted 84% of the householder planning decisions it made in its latest published year — 3 points below the 87% England-wide householder average. The HMO concentration policy — refusing conversions where 10% or more of homes within 100m are already non-family — bites hardest in Bournbrook, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901), Edwardian (1901–1910) and interwar (1918–1939) 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. Selly Oak carries at least one Article 4 direction, and conservation areas including Selly Park and Selly Park Avenues remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Selly Oak is determined against an 8-week statutory target.
Bournbrook (dense Victorian terraces beside the university, largely student HMOs), Selly Park (a conservation area of spacious plots and architect-designed houses), Selly Park Avenues (a distinct conservation area of Edwardian avenue housing), Tiverton Road (terraced streets in the thick of the student lettings market), Weoley Castle edge (interwar council-built semis to the west) and Ten Acres (terraces and light-industrial frontages towards Stirchley) — these are the Selly Oak pockets our drawings cover most. Heritage designations here include Selly Park and Selly Park Avenues. Birmingham City Council weighs each proposal against Birmingham Development Plan (2017) and the Birmingham Design Guide / relevant SPDs, where the Selly Park conservation-area appraisal protects mature planting, front-boundary walls and generous plot spacing. Much of the Bournbrook terraced stock operates as HMOs and converted flats, none of which hold householder permitted-development rights.. On roofs the borough is gabled roofs on the terraced streets and hipped roofs on the Selly Park villas and interwar semis, over Victorian and Edwardian terraces across Bournbrook and the student core, larger architect-designed villas in Selly Park and interwar semi-detached houses on the outer estates.
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. Birmingham City 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.
Selly Oak is largely Victorian and Edwardian terraces across Bournbrook and the student core, larger architect-designed villas in Selly Park and interwar semi-detached houses on the outer estates, 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 Selly Oak's conservation areas — including Selly Park and Selly Park Avenues — 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. Selly Oak sits at the heart of Birmingham's student belt, where the city-wide Article 4 direction requires planning permission for any C3-to-C4 HMO conversion, while the Selly Park and Selly Park Avenues conservation areas protect the leafier residential streets to the east.
An annexe almost always needs an application to Birmingham City 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 Birmingham City Council has to test, rather than leaving the officer to assume the worst.
Below is Birmingham City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Birmingham grants a high share of householder applications overall, but Selly Oak is defined by HMO-concentration control in the student core set against conservation protection in Selly Park. 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.
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 Bournbrook, Selly Park and Selly Park Avenues, 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 edwardian terraces across bournbrook and the student core, 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.
The HMO concentration policy — refusing conversions where 10% or more of homes within 100m are already non-family — bites hardest in Bournbrook. Where Birmingham City 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 Selly Oak. A few of the areas where multigenerational schemes come up most often:
Annexe and granny-flat drawings for Bournbrook — dense Victorian terraces beside the university, largely student HMOs — planned to stay ancillary and drawn to Birmingham City Council's policies.
Annexe and granny-flat drawings for Selly Park — a conservation area of spacious plots and architect-designed houses — planned to stay ancillary and drawn to Birmingham City Council's policies.
Annexe and granny-flat drawings for Selly Park Avenues — a distinct conservation area of Edwardian avenue housing — planned to stay ancillary and drawn to Birmingham City Council's policies.
Annexe and granny-flat drawings for Tiverton Road — terraced streets in the thick of the student lettings market — planned to stay ancillary and drawn to Birmingham City Council's policies.
Annexe and granny-flat drawings for Weoley Castle edge — interwar council-built semis to the west — planned to stay ancillary and drawn to Birmingham City Council's policies.
Annexe and granny-flat drawings for Ten Acres — terraces and light-industrial frontages towards Stirchley — planned to stay ancillary and drawn to Birmingham City Council's policies.
Three similar buildings, three different consents. This is what separates them.
| What you build | Planning status | Key test | What Birmingham City 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 Birmingham City 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 Selly Oak.
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 Birmingham City Council's policies.
We submit the application with a supporting statement on use, manage validation and case-officer queries, and revise free until Birmingham City 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 Selly Oak we prepare a full application to Birmingham City 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. Birmingham City 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 Selly Oak 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 Selly Oak, particularly near designated areas such as Selly Park and Selly Park Avenues. Birmingham City 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 Selly Oak address specifically. Birmingham City 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 Selly Oak address specifically. Birmingham City 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 Selly Oak address specifically. Birmingham City Council is the decision-maker.
We quote each Selly Oak 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 Birmingham City Council approves. Call 020 7864 7245 to start.
Answer five quick questions and get a free planning score for your exact address — instantly. Then, if you want the full picture, unlock the detailed analysis: your council's live approval rates, local precedents, constraints on your street and a step-by-step route to permission.
Same fixed quotes, same fast drawings — wherever your project is.