
Annexe and granny-flat drawings for Brent homes — designed to stay ancillary to the main house rather than become a separate dwelling, drawn to Brent Council's policies, delivered in days and revised free until your decision.
Brent Council granted 85.5% of the householder planning decisions it made in its latest published year — 4.799999999999997 points below the 90.3% England-wide householder average. Flat conversions and HMOs draw heightened scrutiny on amenity, refuse storage and cycle parking given the borough's Article 4 stance, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901), Edwardian (1901–1910), interwar (1918–1939) 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. Brent carries at least one Article 4 direction, and conservation areas including Queen's Park, Mapesbury and Sudbury Court remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Brent is determined against an 8-week statutory target.
Kilburn (dense Victorian terraces, much of it converted to flats), Willesden (Victorian and Edwardian terraces around Willesden Green), Wembley (interwar semis and postwar housing near the stadium), Harlesden (tightly packed Victorian terraced streets), Kingsbury (classic 1930s Metro-land semi-detached estates) and Queen's Park (red-brick terraces framing the Queen's Park conservation area) — these are the Brent pockets our drawings cover most. Heritage designations here include Queen's Park, Mapesbury, Sudbury Court, Roundwood and Brondesbury. Brent Council weighs each proposal against Brent Local Plan and the Design Guide for New Development SPD, where the loss of family-sized housing is resisted, so schemes that carve up larger homes must justify the mix. Converted flats are very common through Kilburn, Willesden and Cricklewood, and none of them hold householder permitted-development rights.. On roofs the borough is London butterfly roofs on the inner terraces and hipped roofs on the Metro-land semis, over Victorian and Edwardian terraces across Kilburn and Willesden, interwar semi-detached houses around Wembley and Kingsbury and converted period flats and maisonettes.
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. Brent 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.
Brent is largely Victorian and Edwardian terraces across Kilburn and Willesden, interwar semi-detached houses around Wembley and Kingsbury and converted period flats and maisonettes, 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 Brent's conservation areas — including Queen's Park and Mapesbury — 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. Brent operates a borough-wide Article 4 direction removing the permitted right to convert family homes into small HMOs, and conservation areas such as Mapesbury layer further restrictions on top.

An annexe almost always needs an application to Brent 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 Brent Council has to test, rather than leaving the officer to assume the worst.
Below is Brent Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Brent grants a little below the London average of householder applications, with intense conversion and HMO demand meeting firm amenity scrutiny the defining tension. 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 Kilburn, Willesden and Wembley, 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 kilburn and willesden, 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.
Flat conversions and HMOs draw heightened scrutiny on amenity, refuse storage and cycle parking given the borough's Article 4 stance. Where Brent 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 Brent. A few of the areas where multigenerational schemes come up most often:
Annexe and granny-flat drawings for Kilburn — dense Victorian terraces, much of it converted to flats — planned to stay ancillary and drawn to Brent Council's policies.
Annexe and granny-flat drawings for Willesden — Victorian and Edwardian terraces around Willesden Green — planned to stay ancillary and drawn to Brent Council's policies.
Annexe and granny-flat drawings for Wembley — interwar semis and postwar housing near the stadium — planned to stay ancillary and drawn to Brent Council's policies.
Annexe and granny-flat drawings for Harlesden — tightly packed Victorian terraced streets — planned to stay ancillary and drawn to Brent Council's policies.
Annexe and granny-flat drawings for Kingsbury — classic 1930s Metro-land semi-detached estates — planned to stay ancillary and drawn to Brent Council's policies.
Annexe and granny-flat drawings for Queen's Park — red-brick terraces framing the Queen's Park conservation area — planned to stay ancillary and drawn to Brent Council's policies.
Three similar buildings, three different consents. This is what separates them.
| What you build | Planning status | Key test | What Brent 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 Brent 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 Brent.
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 Brent Council's policies.
We submit the application with a supporting statement on use, manage validation and case-officer queries, and revise free until Brent 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 Brent we prepare a full application to Brent 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. Brent 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 Brent, particularly near designated areas such as Queen's Park and Mapesbury. Brent 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 Brent address specifically. Brent 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 Brent address specifically. Brent 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 Brent address specifically. Brent Council is the decision-maker.
We quote each Brent 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 Brent 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.