Annexe and granny-flat drawings for Kensington and Chelsea homes — designed to stay ancillary to the main house rather than become a separate dwelling, drawn to the Royal Borough of Kensington and Chelsea's policies, delivered in days and revised free until your decision.
the Royal Borough of Kensington and Chelsea granted 85% of the householder planning decisions it made in its latest published year — 2 points below the 87% England-wide householder average. The borough runs the strictest basement policy in London — broadly one storey deep, under no more than half the garden, with a construction traffic management plan, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837) and Victorian (1837–1901) housing stock sets the design brief on most streets.
Under Class B, a rear dormer stays permitted development up to 40m³ of added roof volume on a terrace or 50m³ on a semi-detached or detached house, while Class A allows a single-storey rear extension of 3m beyond the original rear wall on a terrace and 4m on a detached house before a full application is needed. Kensington and Chelsea carries at least one Article 4 direction, and conservation areas including Chelsea, Kensington and Holland Park remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Kensington and Chelsea is determined against an 8-week statutory target.
Chelsea (stucco terraces and mews streets off the King's Road), Kensington (grand stucco terraces and mansion blocks), Notting Hill (the Ladbroke Estate's stucco terraces around communal garden squares), Holland Park (large detached villas and substantial mansion flats), Knightsbridge (red-brick mansion blocks and stucco terraces) and Earls Court (tall Victorian terraces widely subdivided into flats) — these are the Kensington and Chelsea pockets our drawings cover most. Heritage designations here include Chelsea, Kensington, Holland Park, Ladbroke and Brompton. the Royal Borough of Kensington and Chelsea weighs each proposal against the RBKC Consolidated Local Plan and the Basements SPD, where with the roofscape closely protected, mansard and roof additions are judged against the prevailing profile of each terrace group. Subdivided period houses are common around Earls Court and Notting Hill, and converted flats hold no householder permitted-development rights.. On roofs the borough is concealed butterfly roofs behind the terrace parapets and mansard roofs added to the stucco terraces, over stucco-fronted Georgian and Victorian terraces, purpose-built mansion blocks and mews houses behind the main streets.
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. the Royal Borough of Kensington and Chelsea 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.
Kensington and Chelsea is largely stucco-fronted Georgian and Victorian terraces, purpose-built mansion blocks and mews houses behind the main streets, 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 Kensington and Chelsea's conservation areas — including Chelsea and Kensington — 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. Almost the entire borough falls within a conservation area, and Article 4 directions strip out permitted-development rights so even minor external changes on the Ladbroke or Chelsea streets need consent.
An annexe almost always needs an application to the Royal Borough of Kensington and Chelsea. 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 the Royal Borough of Kensington and Chelsea has to test, rather than leaving the officer to assume the worst.
Below is the Royal Borough of Kensington and Chelsea's real householder decision record, drawn from official planning statistics and refreshed as new data lands. The Royal Borough grants a fair share of householder applications but under exacting design control, with borough-wide conservation status and its restrictive basement policy the defining constraints. 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.
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 Chelsea, Kensington and Notting Hill, 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 stucco-fronted 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 borough runs the strictest basement policy in London — broadly one storey deep, under no more than half the garden, with a construction traffic management plan. Where the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea. A few of the areas where multigenerational schemes come up most often:
Annexe and granny-flat drawings for Chelsea — stucco terraces and mews streets off the King's Road — planned to stay ancillary and drawn to the Royal Borough of Kensington and Chelsea's policies.
Annexe and granny-flat drawings for Kensington — grand stucco terraces and mansion blocks — planned to stay ancillary and drawn to the Royal Borough of Kensington and Chelsea's policies.
Annexe and granny-flat drawings for Notting Hill — the Ladbroke Estate's stucco terraces around communal garden squares — planned to stay ancillary and drawn to the Royal Borough of Kensington and Chelsea's policies.
Annexe and granny-flat drawings for Holland Park — large detached villas and substantial mansion flats — planned to stay ancillary and drawn to the Royal Borough of Kensington and Chelsea's policies.
Annexe and granny-flat drawings for Knightsbridge — red-brick mansion blocks and stucco terraces — planned to stay ancillary and drawn to the Royal Borough of Kensington and Chelsea's policies.
Annexe and granny-flat drawings for Earls Court — tall Victorian terraces widely subdivided into flats — planned to stay ancillary and drawn to the Royal Borough of Kensington and Chelsea's policies.
Three similar buildings, three different consents. This is what separates them.
| What you build | Planning status | Key test | What the Royal Borough of Kensington and Chelsea 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 the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea.
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 the Royal Borough of Kensington and Chelsea's policies.
We submit the application with a supporting statement on use, manage validation and case-officer queries, and revise free until the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea we prepare a full application to the Royal Borough of Kensington and Chelsea 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. the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea, particularly near designated areas such as Chelsea and Kensington. the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea address specifically. the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea address specifically. the Royal Borough of Kensington and Chelsea 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 Kensington and Chelsea address specifically. the Royal Borough of Kensington and Chelsea is the decision-maker.
We quote each Kensington and Chelsea 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 the Royal Borough of Kensington and Chelsea approves. Call 020 7864 7245 to start.
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