Kitchen Extensions Hayes

In Hayes a kitchen extension is typically built onto a 1930s semi or a post-war family house. The VOA count puts 24% of homes here as terraces and 32% as semis or detached houses, and houses keep householder permitted development rights where flats have none. Hillingdon has its own depth and height limits for single storey rear additions, and a borough-wide Article 4 Direction removes permitted development beyond 4 metres, so the drawing starts from those numbers.

In Hayes, 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 Hayes: 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.

How deep a rear kitchen extension in Hayes can go

Where a planning application is needed, the depth Hillingdon will support is set by the plot width and the house type. 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, or 3.6 metres on a wider plot. A detached house is held to 4.0 metres. In Hayes that means measuring the plot width first, because the width decides which figure your designer works to.

Height is capped too. Hillingdon limits a flat roofed single storey addition to 3.0 metres from ground level and a pitched or sloping roof to 3.4 metres. On a 1930s semi with a step down from the back door to the garden, those figures are measured from the ground outside, so a sunken floor or a lower patio changes how much ceiling you actually get inside. We check levels on the first visit so the drawings and the structure agree.

Housing in Hayes

About 16,650 homes are listed for Hayes, and the mix is 58% houses to 42% flats, with 52% built after 1945, 44% in 1919 to 1939 and 4% earlier. 30% of homes here are semi-detached; a semi in Hayes can take its kitchen extension across the back and round into the side passage, which leaves room for a utility behind the kitchen.

Permitted development and the Hillingdon rear extension direction

Permitted development in Hayes is narrower than the national headline suggests. Nationally a single storey rear extension can go four metres past the original rear wall of a detached house or three metres for any other house, and prior approval can take that to eight or six metres. Hillingdon's large rear extensions Article 4 Direction has covered the whole borough since 22 September 2014 and removes permitted development for anything more than 4 metres beyond the original rear wall. So the prior approval route stops at 4 metres here.

For you this means a three metre kitchen on a Hayes semi can still be built without a planning application, provided the house keeps its permitted development rights and meets the other conditions. Between three and 4 metres a semi or terrace needs prior approval, and anything deeper needs householder permission. A lawful development certificate is a sensible record for the permitted development option, because a buyer's solicitor may ask for it later. Whoever prepares the drawings makes those applications in your name; we build to the consent and give them the programme and construction details they need.

Side additions and the width rule on Hayes semis

A side addition on a Hayes semi is limited by width before it is limited by anything else. Hillingdon Policy DMHD 1 says side extensions should not exceed half the width of the original property. On a 1930s semi with a side passage and a garage, that rule often decides whether a wraparound kitchen is realistic or whether the side piece stays as a utility and boot room while the main kitchen goes to the rear.

The side wall usually runs along a boundary, so the footings, gutter line and any roof overhang have to stay on your side unless the neighbour agrees otherwise. Where the work involves the boundary wall or digging close to the neighbour's foundations, the building owner serves notice under the Party Wall Act before we dig. In the Hayes Village Conservation Area every side extension needs householder planning permission, and a flat roofed extension there is expected to finish with a parapet. We set out the footprint and agree it with you on site before excavation.

Flats in Hayes and why they need permission for any extension

A ground floor flat in Hayes has no householder permitted development rights, so any extension to it needs a full planning application. That matters here because the VOA stock count records 42% of homes in Hayes as flats. The permitted development rules for extensions apply to houses only and not to flats and maisonettes, whatever the size of the garden. A flat in a converted house and a flat in a purpose-built block are treated the same way, so even a modest rear kitchen needs that application.

The lease matters as much as the planning. The freeholder usually has to consent to structural alterations and to building on the garden, and the flat above may have rights under its own lease that the freeholder has to weigh, for example where the new roof sits below its windows. We price a flat kitchen extension only once the lease position is known, because a refused licence to alter stops the job however good the drawings are, and it is better to know that before paying a designer.

• Utility rooms and larders at the back of the extension
• Steel beams and goalpost frames into the existing house
• Airbrick ducts to keep existing timber floors ventilated

VOA Council Tax stock of properties, March 2025, for Hayes End, Hayes Town North, Hayes Town & Lake Farm and Hayes South. Counts rounded by the VOA.

Plenty of Hayes projects start with one job and grow, so it helps to see kitchen renovation in Hayes, kitchen extensions across Hillingdon, fitting the kitchen itself, how building control inspects an extension, kitchen extensions across London and Renovating a Victorian Terrace.

Why Hayes Homeowners Choose GS Renovation

We run the whole kitchen extension as one programme, from the groundworks and drainage through the steel into the back of the house to the kitchen fit-out, so there is no gap between builder and kitchen fitter. The structural engineer we appoint sizes the beam and we build to the approved drawings. You get a written quotation after a site visit and one point of contact through the job. The founder has more than three decades of hands-on building experience.

• Old kitchen kept in use until the new shell is weathertight
• Screed left to dry before the kitchen floor finish goes down
• Registered in England, Companies House no. 14611254

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.