House Extensions in Notting Hill W11: Rear and Side-Return Extensions on the Stucco Terraces, Conservation Areas, Article 4 and Prices
By Anderson & the LCCL Construction Team | Finchley N3
Notting Hill W11 is the stucco terraces and garden squares of the Ladbroke estate, the brick and stucco villas towards Holland Park, the mews behind Westbourne Grove and the terraces off Portobello Road. Nearly every residential street is inside a conservation area — Pembridge, Ladbroke, Norland and Kensington Park cover most of the postcode — and the typical house is a terrace with a two- or three-storey rear addition, a narrow side return beside it and a small walled garden. That combination decides which extension works and which planning route it takes.
As LABC Building Excellence Award Winners 2024 for Best Residential Extension in London — and London Regional Winner 2026 for Best Conversion or Alteration to an Existing Home — we design and build rear, side-return and wraparound extensions across Kensington and Chelsea and Westminster, and the Second Avenue W10 kitchen extension in the photograph — a few streets north of Notting Hill in Queen's Park — is the kind of project a W11 terrace most often needs.
Not sure whether your project needs planning permission? Enter your postcode and tick what you want to build — about two minutes, free, and the from-price for each part that qualifies appears on screen and in your inbox.
The Notting Hill house and the extension that suits it
On a terrace with a rear addition the side return is the space to take: a strip one to two metres wide between the addition and the boundary, roofed over with a rooflight or a glazed strip, which turns a narrow back kitchen into a full-width kitchen-diner across the rear of the house. Where the garden allows, a rear extension across the full width adds a dining or living area beyond it, and the two together — the wraparound — make the open-plan ground floor most buyers in W11 expect. On the villas with a wider plot a plain rear extension of three to four metres does the same job without touching the side.
Two things set Notting Hill apart from an ordinary London terrace. The gardens are small, often walled and often shared with a communal garden behind, so the extension depth is set by what is left outside as much as by the rules. And the rear elevations are visible from neighbouring gardens and the communal squares, so the conservation officer looks at the back of the house as carefully as the front.
Is a house extension permitted development in Notting Hill?
Sometimes, and it pays to be precise. A single-storey rear extension on a house is permitted development where it projects no more than 3 metres from the original rear wall on a terrace or semi (4 metres on a detached house), is no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and uses materials similar to the house. Being in a conservation area does not by itself remove that right, so a modest rear extension on a Notting Hill terrace can still go ahead under a Lawful Development Certificate (£274, up to eight weeks). What a conservation area does remove is the larger-home-extension route — the 6-metre prior-approval extension is not available on conservation-area land — and the right to a side extension, which is why a side return in W11 is nearly always a householder planning application (£548, eight weeks). Cladding and most roof changes are also excluded.
On top of that, many Notting Hill streets carry Article 4 directions that bring smaller changes under planning control, and the Royal Borough's conservation-area guidance expects rear extensions on stucco terraces to be subordinate, to keep the rear addition legible and to use render, brick and timber or slim metal glazing rather than full-width frameless glass. A pre-application enquiry before the submission is worth its fee here. Our Planning check reads the conservation-area and Article 4 data for your postcode before it gives an answer; the council has the final say on any application.
Not sure whether your project needs planning permission? Enter your postcode and tick what you want to build — about two minutes, free, and the from-price for each part that qualifies appears on screen and in your inbox.
Building control in Notting Hill
Building regulations apply to every extension whatever the planning route. The Royal Borough's building control team or an approved inspector sees the foundations before they are poured, the steel beams and padstones before they are covered, the damp-proofing and insulation, the drainage, the glazing and the completed extension before the completion certificate is issued. On a terrace the new steel bears on both party walls, so notices under the Party Wall Act go to both neighbours, and the foundations of a Victorian terrace are shallow enough that the excavation usually needs a party wall award of its own. Our structural engineer produces the calculations and the drawings go to building control before anything is dug.
What a house extension costs in Notting Hill
Rear extension (single storey): from £42,000 inc. VAT (£35,000 + VAT), 15–25 m², eight to twelve weeks on site.
Side-return extension: from £42,000 inc. VAT (£35,000 + VAT), 10–20 m², eight to twelve weeks on site.
Wraparound (side return + rear): from £72,000 inc. VAT (£60,000 + VAT), 25–40 m², twelve to sixteen weeks on site.
Double-storey rear extension: from £90,000 inc. VAT (£75,000 + VAT), 30–50 m², sixteen to twenty weeks on site, planning application always required in W11.
Loft and extension together: from £98,400 inc. VAT (£82,000 + VAT) under one contract.
Every figure is design and build at economy specification, shell-and-plaster finish, and includes the survey, the drawings, the structural calculations, building control and a 12-month workmanship guarantee, with a 10-year LABC structural warranty on every project. The final price is fixed in writing after the survey and is postcode dependent. In Notting Hill the items that move the figure are the ones the conservation area asks for — render and timber or slim-profile glazing, a parapet or a lead roof rather than a flat felt one — and the knock-through into the existing rooms, which is priced as its own line.
Our project at Second Avenue W10
Second Avenue is in Queen's Park, a short way north of Notting Hill, in a terrace of the same kind as the smaller Notting Hill streets: narrow frontage, rear addition, a short walled garden. We designed and built a kitchen extension that took the side return and squared off the back of the house, with a long rooflight over a white island, navy cabinets along the party wall, a parquet floor running out to bi-fold doors and a patio flush with the kitchen floor so the garden reads as part of the room. The structure — a steel across the old rear wall and a second along the side return — was the invisible half of the budget, which is the point of the advice below.
Anderson's advice
The item clients most often forget when they open up a ground floor is the steel. Taking out the rear wall and the side-return wall of a Notting Hill terrace needs two beams and sometimes a goalpost frame with pads under the posts, and that structure is £4,000 to £12,000 that is invisible on the architect's plan until the engineer has run the calculations. Our team prices it as its own line on the first estimate so it never arrives as a surprise at the survey. If a competing quote does not show it, ask where it is.
Why Notting Hill homeowners choose LCCL
One contract and one point of contact: our team surveys the house, draws the extension to what the conservation officer will accept, runs the pre-application enquiry and the householder application or the Lawful Development Certificate, produces the structural calculations, serves the party wall notices, deals with building control and builds the extension with the same site team from excavation to completion certificate. Clients see one price, one programme and one person to call.
What our clients say
“Hired LCCL Construction to design and build us a rear house extension. Found them easy to work with and are pleased with the results. They have been recommended to us for the whole build including designs and construction. The rear extension feels amazing, it is spacious and bright, the project finished on expected budget and within the timeframes agreed.”
— James Grimsdale, Google Reviews
Frequently asked questions
Do I need planning permission for a rear extension in Notting Hill?
Not always. A single-storey rear extension within the ordinary permitted development limits — 3 metres deep on a terrace, 4 metres on a detached house, no higher than 4 metres — remains permitted development inside a conservation area, and we confirm it with a Lawful Development Certificate. The 6-metre larger-home-extension route and any side extension are not available in a conservation area, so a side return or a wraparound in W11 needs a householder planning application; the council has the final say.
How much does a house extension cost in Notting Hill?
From £42,000 inc. VAT (£35,000 + VAT) for a rear or side-return extension, £72,000 inc. VAT (£60,000 + VAT) for a wraparound and £90,000 inc. VAT (£75,000 + VAT) for a double-storey extension, design and build at economy specification. Conservation-area materials and the structural opening-up are priced on the drawings and the final figure follows the survey.
Can I extend into the side return of a Notting Hill terrace?
Yes, with a householder planning application: side extensions are not permitted development in a conservation area. Most W11 side returns are approved where the extension is single storey, subordinate to the rear addition and finished in materials that match the house; a pre-application enquiry tells you what the officer will accept before the drawings are finished.
Get a figure for your own project
Not sure whether your project needs planning permission? Enter your postcode and tick what you want to build — about two minutes, free, and the from-price for each part that qualifies appears on screen and in your inbox.
To book a free 30-minute consultation call about your Notting Hill extension, call LCCL Construction on 020 8037 7332 or get an instant estimate at https://www.lcclconstruction.co.uk/instant-quote.
One team, one contract, one point of contact — from first sketch to handover.
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