Kitchen Extensions Uxbridge
Rear, side return and wraparound kitchen extensions in Uxbridge, the room, the services and the kitchen built as one job.
- Rated 4.9 from 31 reviews on MyBuilder
- London guide: £45,000 to £97,500
- Free site survey, itemised quote
A kitchen extension in Uxbridge is more often built on a semi or detached house than on a terrace: 33% of homes here are semi-detached or detached and 16% are terraced. Hillingdon sets its own depth and height limits for these rooms, and a borough-wide direction removes permitted development for anything over 4 metres beyond the original rear wall. We build the shell, the steel into the house, the drainage and the kitchen itself as one programme.
In Uxbridge, a rear kitchen extension of about 30 square metres typically costs £45,000 to £97,500 excluding VAT, or £60,000 to £100,000 for a side return (indicative London ranges, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Uxbridge: the structural engineer we appoint designs the foundations and steel, we build the room and fit the kitchen, and a registered electrician certifies the electrics.
Price guide
| Work | Indicative London range |
|---|---|
| Rear kitchen extension, about 30 square metres, ex VAT | £45,000 to £97,500 |
| Side return kitchen extension, standard to high specification | £60,000 to £100,000 |
| Wraparound kitchen extension, standard to high specification | £80,000 to £130,000 |
| Side return build rate, per square metre of new floor | £2,400 to £3,200 |
| Kitchen supplied and fitted within the extension | £5,000 to £14,000 |
| Structural engineer's fee | £950 to £2,500 |
Indicative London ranges (Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Cost and Planning Guide.
Quick estimate for Uxbridge
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How deep a rear kitchen extension can go in Uxbridge
The depth is set by the plot width and the house type before any design starts. Hillingdon Policy DMHD 1 says a single storey rear extension on a terraced or semi-detached house should not exceed 3.3 metres deep where the plot is 5 metres wide or less, and 3.6 metres on wider plots. For a detached house the figure is 4.0 metres. Measure your plot across the back wall first, because that one dimension decides which figure your designer works to in Uxbridge.
Height is limited too. Hillingdon keeps a flat roofed single storey extension to 3.0 metres from ground level and a pitched or sloping roof to 3.4 metres. That cap shapes the kitchen more than people expect: it fixes how thick the roof build up can be, how much fall the flat roof gets, and whether a roof lantern sits proud of the parapet line. We price the roof once those levels are drawn, so the ceiling height inside is known before the steel is ordered.
Housing in Uxbridge
Around 12,630 homes make up Uxbridge on the valuation list; 47% are flats and 53% houses, and 12% date from before 1919, 17% from between the wars and 71% from after 1945. A semi in Uxbridge can take its kitchen extension across the back and round into the side passage, which leaves room for a utility behind the kitchen, and 17% of homes here are semi-detached.
The borough-wide rear extension direction and what it removes
Across Uxbridge, a rear kitchen extension deeper than 4 metres beyond the original rear wall needs planning permission, not permitted development. Hillingdon's Article 4 Direction removes those rights for residential extensions over that depth, and it has applied to the whole borough since 22 September 2014. So the larger prior approval extensions allowed elsewhere stop at 4 metres here, and a deeper family kitchen goes through a householder planning application.
For your programme, that means the design stage sets the start date. An extension within the policy depths can be drawn, submitted and built in a clear sequence, while a deeper scheme adds a decision period before any groundwork. We plan the build around the approved drawings, order the steel and glazing to those dimensions, and do not start digging in Uxbridge until the consent you or your designer obtained is in hand.
Side extensions and wraparounds on Uxbridge semis
A side extension can widen a narrow kitchen on a semi, but Hillingdon Policy DMHD 1 says it should not exceed half the width of the original property. On a semi the side passage is often the only route to the garden and the bins, so the width you gain is weighed against access. A wraparound joins a side piece and a rear piece into one L shaped room. It is not permitted development, so it needs a planning application, and the design has to satisfy both the side and the rear limits.
The junction where the side and rear sections meet is the hard part to build. It usually needs a corner post or a longer steel, a valley or box gutter, and a clear line for rainwater to reach a downpipe. We set out that corner on site against the drawings before the footings go in, so the roof falls, the glazing openings and the kitchen run along the new wall all line up in the finished Uxbridge room.
Conservation areas in Uxbridge change the roof and the paperwork
If your house is in The Greenway, Uxbridge, designated on 16 October 1975, or in Old Uxbridge/Windsor Street, the rules tighten. Hillingdon says planning permission is likely to be required to alter or extend buildings in its conservation areas, and national rules take away permitted development for every side extension on that designated land. Check the boundary on Hillingdon's published maps before you commission drawings, because a house one street away from the line is treated quite differently.
The finish is different as well. In Hillingdon conservation areas and Areas of Special Local Character, a flat roofed single storey extension is expected to have a parapet, which hides the roof edge and changes how the gutter and the fascia are detailed. In Uxbridge we build the parapet in brick to match the house where the drawings ask for it, and take the rainwater through an outlet behind it, which affects the order of the roofing and the brickwork.
- Soil stack and gully rerouting beneath the new floor
- Rear, side return and wraparound kitchen extensions
- Hob gas supply altered by a Gas Safe registered engineer
VOA Council Tax stock of properties, March 2025, for Uxbridge Common & Swakeleys, Uxbridge Central & Brunel and Uxbridge West. Counts rounded by the VOA.
Why Uxbridge Homeowners Choose GS Renovation
GS Renovation runs a kitchen extension in Uxbridge as a single job from the footings to the worktops, so one team owns the sequence. Abdelaaziz Saaid, our founder and director, brings more than three decades of hands-on building. We appoint the structural engineer for the steel, work to the drawings and consent you already have, keep the noisy work inside the permitted hours, and hand over a kitchen that is plumbed, wired by a registered electrician and ready to use.
- Drains surveyed by camera before the footprint is fixed
- A written scope and programme agreed before work starts
- Boiler flue, soil pipe and gully moved off the rear wall in the right order
The kitchen has been fitted to the high standard. Saaid was polite, professional, tidy, he pays attention to a little details that make huge…
It's the second time I have hired George and he has been absolutely professional and the work he did resembles perfectly what I had in mind. Being an…
Saiid did a complete refurbishment of our small bathroom. This involved ripping out the existing bath/shower, basin, toilet, pipework, and tiles and…
FAQ
Frequently Asked Questions about Kitchen Extensions Uxbridge
Why do kitchen extensions quotes in Uxbridge vary so much?
Variation in kitchen extensions quotes across Uxbridge almost always comes from what has been left out. GS Renovation prices structure, trades, approvals and reinstatement after a UB8 survey, so the total can look higher than a quote covering half of it. The honest range is £45,000 to £97,500 excluding VAT for a rear kitchen extension of about 30 square metres (indicative), and where the drain runs under the Uxbridge garden decides both the footprint and where the new sink can go, which a quote without a survey cannot know.
Can a flat in Uxbridge have a kitchen extension under permitted development?
No. Householder permitted development rules for extensions apply to houses only, not to flats and maisonettes. With 47% of homes in Uxbridge being flats, this matters to a lot of owners. Any extension to a flat needs planning permission, and usually the freeholder's consent under the lease as well. A ground floor flat with a garden can sometimes extend, but only through a planning application.
How deep can a kitchen extension be on an Uxbridge semi?
Under national permitted development a semi can extend 3 metres at the back without an application. Where planning permission is needed, Hillingdon Policy DMHD 1 says a single storey rear extension on a semi should not exceed 3.3 metres where the plot is 5 metres wide or less, and 3.6 metres on a wider plot. The borough's Article 4 Direction also removes permitted development beyond 4 metres.
Is a detached house in Uxbridge allowed a deeper kitchen extension?
Yes, a little. Hillingdon's policy figure for a single storey rear extension to a detached house is 4.0 metres. Nationally a detached house can go four metres under permitted development and up to eight metres with prior approval, but the Hillingdon Article 4 Direction removes permitted development beyond 4 metres, so a deeper room needs a planning application here.
How tall can a flat roofed kitchen extension be in Uxbridge?
Hillingdon's policy limits a flat roofed single storey extension to 3.0 metres high and a pitched or sloping roof to 3.4 metres, both measured from ground level. Roof lights and lanterns have to fit within that envelope, so the roof build up, insulation depth and ceiling height are all drawn together before the steel is sized.
Does an Uxbridge kitchen extension need a parapet on the flat roof?
Hillingdon's policy asks for one in a conservation area or an Area of Special Local Character. There, Hillingdon expects a flat roofed single storey extension to finish with a parapet. Elsewhere in Uxbridge a plain fascia and gutter is normal. A parapet adds brickwork and a hidden outlet for rainwater, which changes the roofing order and the build time.
What happens to the drains when the kitchen moves into the extension?
The sink, dishwasher and any island need a route to the existing drain, and a new extension often sits over a manhole or a run of pipe. We expose the drainage early, then reroute it or add an access point inside the new floor. Where a public sewer runs under the footprint, the sewerage company's build over rules apply before the slab is poured.
Can the steel and the kitchen fit-out run in one programme in Uxbridge?
Yes, and that is how we run it. The structural engineer we appoint sizes the steel for the opening into the house, we install it, and the kitchen supplier's measure follows once the walls and floor are set. Building work audible at the boundary in Hillingdon is limited to 8am to 6pm on weekdays and 8am to 1pm on Saturdays, so the loud stages are planned inside those hours.
How big should the kitchen be in an Uxbridge house let as an HMO?
Size it to Hillingdon's standards for shared houses from the start. They ask for a fixed impervious worktop of at least 1500 x 600 mm for every 5 people sharing one set of kitchen facilities. Where the kitchen sits inside another room, the guide is at least 3.7m2 of extra floor area. An extension that falls short of these can hold up the licence for the house.
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