Annexe and granny-flat drawings for Lambeth homes — designed to stay ancillary to the main house rather than become a separate dwelling, drawn to Lambeth Council's policies, delivered in days and revised free until your decision.
Lambeth Council granted 89% of the householder planning decisions it made in its latest published year — 2 points above the 87% England-wide householder average. The loss of family houses to further flat conversion is resisted and frequently the deciding issue, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837), Victorian (1837–1901) and Edwardian (1901–1910) 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. Lambeth carries at least one Article 4 direction, and conservation areas including Clapham Old Town, Stockwell Park and Angell Town remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Lambeth is determined against an 8-week statutory target.
Clapham (Georgian and Victorian terraces around the Old Town and Common), Brixton (Victorian terraces heavily subdivided into flats), Stockwell (Georgian and Victorian streets around Stockwell Park), Herne Hill (Victorian villas and terraces on the Dulwich fringe), Streatham (Edwardian terraces and mansion blocks along the high road) and Kennington (Georgian and Regency terraces near the river) — these are the Lambeth pockets our drawings cover most. Heritage designations here include Clapham Old Town, Stockwell Park, Angell Town, Herne Hill and Leigham Court Estate. Lambeth Council weighs each proposal against Lambeth Local Plan and the council's Alterations and Extensions SPD, where mansards and roof additions on stucco-fronted terraces are measured against whatever original roofline survives on the street. Much of Brixton, Clapham and Stockwell is already converted flats and maisonettes, which hold no householder permitted-development rights.. On roofs the borough is butterfly and valley roofs behind the terrace parapets and mansard and pitched roofs on the taller stucco streets, over Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and 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. Lambeth 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.
Lambeth is largely Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and 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 Lambeth's conservation areas — including Clapham Old Town and Stockwell Park — 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. Alongside the controls in conservation areas such as Clapham Old Town, Lambeth runs a borough-wide Article 4 direction removing permitted-development rights for small shared houses, pulling many HMO changes into the application system.
An annexe almost always needs an application to Lambeth 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 Lambeth Council has to test, rather than leaving the officer to assume the worst.
Below is Lambeth Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Lambeth grants a high proportion of householder applications, but with so much of its stock already split into flats, protecting the remaining family houses is what shapes most refusals. 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, rolling year). Compare every borough on our London approval-rate league table.
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Across Clapham, Brixton and Stockwell, 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 georgian and victorian terraces, 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 loss of family houses to further flat conversion is resisted and frequently the deciding issue. Where Lambeth 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 Lambeth. A few of the areas where multigenerational schemes come up most often:
Annexe and granny-flat drawings for Clapham — Georgian and Victorian terraces around the Old Town and Common — planned to stay ancillary and drawn to Lambeth Council's policies.
Annexe and granny-flat drawings for Brixton — Victorian terraces heavily subdivided into flats — planned to stay ancillary and drawn to Lambeth Council's policies.
Annexe and granny-flat drawings for Stockwell — Georgian and Victorian streets around Stockwell Park — planned to stay ancillary and drawn to Lambeth Council's policies.
Annexe and granny-flat drawings for Herne Hill — Victorian villas and terraces on the Dulwich fringe — planned to stay ancillary and drawn to Lambeth Council's policies.
Annexe and granny-flat drawings for Streatham — Edwardian terraces and mansion blocks along the high road — planned to stay ancillary and drawn to Lambeth Council's policies.
Annexe and granny-flat drawings for Kennington — Georgian and Regency terraces near the river — planned to stay ancillary and drawn to Lambeth Council's policies.
Three similar buildings, three different consents. This is what separates them.
| What you build | Planning status | Key test | What Lambeth 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 Lambeth 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 Lambeth.
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 Lambeth Council's policies.
We submit the application with a supporting statement on use, manage validation and case-officer queries, and revise free until Lambeth 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 Lambeth we prepare a full application to Lambeth 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. Lambeth 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 Lambeth, particularly near designated areas such as Clapham Old Town and Stockwell Park. Lambeth 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 Lambeth address specifically. Lambeth 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 Lambeth address specifically. Lambeth 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 Lambeth address specifically. Lambeth Council is the decision-maker.
We quote each Lambeth 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 Lambeth Council approves. Call 020 7864 7245 to start.
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