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Free 2026 London Planning ReportRear Extension Drawings in Maida Vale W9

Mansion block flat conversion drawings in Maida Vale W9, City of Westminster
Maida Vale · W9 · Westminster

Rear Extension Drawings in Maida Vale W9

Fixed-fee, MCIAT-chartered rear extension drawings for Maida Vale (W9) homeowners — Westminster City Council validation and local constraints handled from the start.

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Maida Vale (W9) in Westminster is defined by two building types: red-brick Edwardian mansion blocks along Elgin and Sutherland Avenues, and wide late-Victorian stucco villas on the streets around them. The Maida Vale conservation area covers them both, and the protected feature is the uniformity — the repeated frontage and the unbroken roofline down a whole avenue.

That uniformity is why roof and front-elevation work is the hardest thing to get through here, and why most W9 projects are internal reconfigurations or rear work instead. Westminster's Article 4 direction removes permitted development rights for basement development, so a lower-ground excavation needs a full planning application from the outset. The more common constraint is simply tenure: the great majority of W9 stock is flats within those mansion blocks, and flats have no permitted development rights in any case, so freeholder consent runs alongside planning whatever the designation says. We confirm tenure and the Article 4 position before drawing to Westminster's guidance.

Mansion block flat conversion drawings in Maida Vale W9, City of Westminster
Isometric illustration of a Maida Vale W9 home rear extension drawings design
Proposed floor plan
Maida Vale W9

Planning in Maida Vale (W9): what to know before you apply

W9 sits within the Maida Vale conservation area, which protects the uniform frontages and rooflines of the Edwardian mansion blocks and late-Victorian stucco villas — making roof and front-elevation changes the most sensitive work here. Westminster's Article 4 direction removes permitted development rights for basement development, so lower-ground excavation needs a full planning application. Most of the district's stock is mansion-block flats, which have no permitted development rights regardless of designation and need freeholder consent alongside the application.

Typical Maida Vale housing stock

Red-brick Edwardian mansion blocks along the main avenues and wide late-Victorian stucco villas on the side streets, the great majority held as flats rather than whole houses.

Streets we regularly draw for in Maida Vale

Elgin Avenue · Sutherland Avenue · Randolph Avenue · Warwick Avenue

What W9 is actually built of

Measured from 224 classified residential buildings in W9, not from a description of the area.

Maida Vale W9 housing mix

Residential building form across the W9 postcode district, from 224 classified buildings.

Attached on more than one side78%
Attached on one side20%
Detached2%
Median building footprint82 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate4.99
Buildings classified224

Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.

Rear Extension Drawings for Maida Vale (W9) homes: the package and the process

Depth is the number the application turns on, and it has to be measured from the original rear wall of the house rather than from whatever is there now. The drawings carry that dimension, the eaves and ridge heights, the position of any rooflight, and the boundary distances on both sides.

Where the scheme goes beyond the standard allowance and relies on the larger home extension route, the drawings serve a second purpose: they are what the council sends to the neighbours during the consultation. A clear, dimensioned proposed elevation answers the objection about overshadowing before it is made.

Depth is limited by the plot as much as by the rules. A long garden behind a terrace can take the full allowance, while a short one runs out before the rules do — and on a semi or detached house the same depth reads very differently from the boundary.

Do I need planning permission for a rear extension in London?

Many single-storey rear extensions qualify as permitted development, meaning no planning application is needed, provided depth, height and materials stay within set limits. That changes if your property sits in a conservation area or is subject to an Article 4 direction, both of which can remove permitted development rights across a street or borough — in that case a full householder planning application is required regardless of size.

Even where an extension qualifies, most homeowners obtain a Lawful Development Certificate to confirm that status in writing before building — useful for mortgage lenders, buyers and Building Control. We check your property against your borough's constraints before recommending a route.

How deep can a single-storey rear extension go?

Depth is the main constraint on a rear extension, and it depends on your house type and whether you use standard permitted development or the larger home extension scheme.

Permitted development

Standard permitted development allows a single-storey rear extension up to 3 metres deep for terraced and semi-detached houses, or 4 metres for detached houses, generally with eaves height limited to match or stay close to the existing house.

Larger home extension scheme

The prior-approval scheme extends this to 6 metres for terraced and semi-detached houses and 8 metres for detached houses. Your council writes to affected neighbours; if none object within the notification period, approval follows without a full planning application. If an objection is raised, the council assesses the impact on neighbouring light and outlook itself, rather than automatically refusing, so a well-considered design still has a good chance of approval.

Designing the kitchen-diner: rooflights, bi-folds and daylight

Most rear extensions exist to create one open-plan kitchen, dining and living space, so the drawing work focuses on getting light and flow right within the depth you are allowed.

  • Structural opening sized for bi-fold or sliding doors across most of the rear elevation
  • Rooflights or a roof lantern positioned to light the centre of the room, away from the shadow line of the main house
  • Open-plan layout tested against the 45-degree rule, which protects daylight to your neighbours' windows and can limit how close a flank wall or roof comes to the boundary
  • Floor build-up and threshold detail coordinated so the new floor meets the existing one without a step
Rear extension routes at a glance
RouteWhen it appliesTypical fee
Permitted development (Lawful Development Certificate)Depth within 3m (terraced/semi) or 4m (detached), height and materials within PD limitsPD/LDC pack ~£950–£1,450
Larger home extension (prior approval)Depth up to 6m (terraced/semi) or 8m (detached), with neighbour notificationfrom £1,100
Full householder planning permissionExtension exceeds PD/larger-home limits, or the property is in a conservation area with an Article 4 directionFull Planning pack ~£1,600–£2,400
Planning + Building Regulations (structural)Combined planning and construction-ready pack with structural calculations for the opening and roofPlanning + Building Regs pack ~£2,200–£3,850
Sheet from a rear extension drawings package drawn for a Maida Vale property in W9, showing the existing and proposed arrangement at scale
A sheet from the rear extension drawings package we submit to Westminster City Council for Maida Vale (W9) properties.
FAQ

Rear Extension Drawings in Maida Vale W9 — FAQs

How much does a rear extension cost to design in London?+
Rear extension drawings start from £1,100, with the final fee set by the route your extension takes — permitted development, prior approval or full planning — and whether you need building regulations and structural calculations bundled in. The fee is fixed and agreed upfront.
Do I need an architect for a rear extension?+
No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, producing the same council-accepted drawings as an architect for a fixed fee typically around 30% lower.
How long does it take to get rear extension drawings?+
Drawings are typically ready around 7 days from survey. Once submitted, councils have a statutory 8-week period to determine a standard householder planning application.
What is the 45-degree rule?+
It is a daylight test many London councils apply to check that a rear extension does not block too much light to a neighbour's nearest window, measured as a line drawn at 45 degrees from that window. We check it before submission, not after a refusal.
Will I need a Party Wall Agreement for a rear extension?+
Only if your foundations or new walls sit on or near the boundary with a neighbouring property. A straightforward rear extension set within your own plot often does not trigger the Party Wall etc. Act 1996, unlike a Side Return or Wraparound extension, which usually does.
Do I need planning permission for works in Westminster?+
Almost always. The great majority of Westminster falls within a conservation area and a high proportion of buildings are listed, so a full planning application — and often listed-building consent — is usually required even for modest works. Permitted development rarely applies. We screen conservation, listing and lease constraints for your address before recommending a route.
I live in a mansion block — what extra consent might I need?+
Much of Westminster's stock is mansion-block or garden-square terrace, and the lease frequently requires the freeholder's consent alongside planning for external alterations. We confirm the lease position early and design a scheme that satisfies both the freeholder and the council, since either can block an otherwise sound proposal.
Will I need a Basement Impact Assessment in Westminster?+
Usually, for below-ground works. The City Plan basement policy requires a basement impact assessment and limits scale. If you are considering a basement or lower-ground extension we flag the requirement early and coordinate the structural and drainage input so the application is complete when submitted.
How long does Westminster City Council take to decide?+
Westminster determines most householder applications within the statutory eight-week period once validated, though listed-building, basement and conservation cases frequently attract additional consultation. We prepare submissions to the council's exacting validation and design standards to avoid the drawing queries that cause most delays.
How much do planning drawings cost in Westminster?+
We agree a fixed fee before we start, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until the council approves. Heritage-led, listed-building and basement schemes require more evidence than a standard extension, so we quote once we understand your address and scheme rather than by the hour.
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