Kitchen Extensions Pinner

Many kitchen extensions in Pinner go onto a house built between the wars: 39% of the homes here date from 1919 to 1939, and 46% are semi-detached or detached, against 14% terraced. That points to a rear extension across the back of a semi, sometimes wrapping round the side, rather than the narrow side return of an inner London terrace. We build the shell, bring the steel into the house, run the drainage and fit the new kitchen as one programme, working to the drawings and consents you or your designer hold.

In Pinner, 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 Pinner: 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 Pinner semi can go at the back

The depth of a rear kitchen extension on a Pinner semi is set first by national permitted development: three metres beyond the original rear wall for any house other than a detached one, and four metres for a detached house. Through the prior approval process that Harrow runs, that can rise to 6 metres for a semi or terrace and 8 metres for a detached house. That larger route is not available on Article 2(3) land such as a conservation area. The rear extension must also stay within four metres in height.

Prior approval is not a formality. Harrow consults the immediate neighbours and the process can last 42 days, so we plan the start date around that window rather than ordering steel and booking a skip while the decision is open. Once the depth is agreed we set out the footings from the original rear wall, which on some interwar semis sits behind a later lean-to or conservatory. That later addition counts against the permitted depth, and it usually has to come down first.

Housing in Pinner

Pinner has about 11,760 homes on the Council Tax list: 18% pre-1919, 39% interwar and 43% post-war, with flats making up 36% and houses 64%. 28% of homes here are semi-detached; a semi in Pinner can take its kitchen extension across the back and round into the side passage, which leaves room for a utility behind the kitchen.

Harrow's design guide and the boundary wall in Pinner

Where a Pinner kitchen extension needs planning permission, Harrow's Residential Design Guide SPD shapes the side walls. It caps a flat-roofed single storey rear extension at 3 metres high on the boundary, or 3.5 metres at the mid-point for a pitched roof. Its two for one rule means any extra depth has to be set in from the side boundaries by twice the extra depth you want. A permitted development extension is not assessed against the SPD.

In practice that decides where the steel goes and how the roof falls. A set-in flank wall leaves a strip beside the neighbour that has to be drained and finished, and a pitched roof kept low at the boundary changes the ceiling line inside the kitchen. We read those limits off the approved drawings before we order anything, because a parapet built a course too high in Pinner is expensive to take down.

Roof lights, glazing and the Pinner conservation areas

Glazing and the roof are where Pinner's conservation areas bite on a kitchen project. In West Towers Conservation Area an Article 4 direction on all houses brings rooflights and new roof tiles under planning control. In the core of the Pinnerwood Park Estate Conservation Area Article 4 directions cover dormer windows, rooflights and gabling a hipped roof. On designated land such as a conservation area, every side extension, including the side leg of a wraparound, needs householder planning permission, whatever its size.

Wherever the house is, a scheme that needs planning permission is also judged against Harrow's SPD on glass near the neighbour. Large windows in the wall of a side extension within 3m of a boundary are unacceptable, and a conservatory within 3 metres of a boundary would normally need brick flank walls or solid panels. So in Pinner we tend to bring light in from the roof and the rear wall, with the flanks kept solid, and order the glazing only once the consented elevations are fixed.

Drains, inspections and signing off in Pinner

The drain run behind a Pinner house can decide the paperwork route. Harrow requires a full plans application, not a building notice, where an extension is built over or within 3m of a public drain or sewer shown on the sewer map. We trace the manholes early, before the footing trench is dug, so that the sink, dishwasher and any new gully can be positioned against the real falls rather than against a guess on the drawing.

Harrow Building Control visits sites Monday to Friday between 10 in the morning and 3 in the afternoon, and offers a same-day inspection, subject to surveyor availability, if the office is phoned before 9:00. We book foundation, drainage and steel inspections into that window so the concrete lorry is not waiting. Where Harrow is the building control body, a completion notice under Regulation 16(4a) has to go in at the end, or the completion certificate is withheld. A buyer's solicitor will ask for that certificate when you sell.

• Flat roofs with rooflights or a roof lantern over the kitchen
• 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 Pinner Green, Pinner Central, Pinner Road and Pinner South. Counts rounded by the VOA.

Before committing to kitchen extensions in Pinner, it is worth looking at kitchen renovation in Pinner, kitchen extensions across Harrow, fitting the kitchen itself, sign-off by building control on a kitchen extension, our London kitchen extensions page and Side Return Extension Cost.

The GS Renovation Difference in Pinner

You get one team from the first trench to the last cupboard door. We coordinate the structural engineer we appoint, programme the building control visits, keep the old kitchen running as long as the layout allows, and fit the new one inside the extension we built, so the worktops meet walls we know are true. You deal with one contact for dates, deliveries and decisions, and the drawings, programme and inspection records come to you when the job closes.

• Structural engineer instructed and coordinated on your behalf
• New floor level matched to the existing house, with no step at the opening
• Kitchen layout agreed before the foundations, so the services land in the right place

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.