Building work in Kew: area guide

This is our area guide to building work in Kew (TW9, Richmond upon Thames): the housing, the council rules that apply (Richmond Council for planning) and every service we offer here. For whole-house refurbishment go to Home renovation in Kew.

Much of Kew's housing is two storey Victorian terraces, mostly bay fronted, with a rear closet wing and a garden that is short by Richmond standards. Around Kew Green and the streets towards the National Archives and Kew Bridge the question is usually light and layout rather than square metres, so side return infills (house extensions), wide rear openings and reworked kitchens make up most of the work. Every structural opening is formed to an appointed engineer's design, and we never produce those calculations ourselves.

Kew has around 4,470 homes on the Council Tax list: 31% post-war, 6% interwar and 62% predate 1919, with 43% flats and 57% houses. VOA Council Tax stock of properties, March 2025, for Kew Gardens. Counts rounded by the VOA.

Getting light into a narrow Kew plan means steel first

The classic Kew problem is a dark middle room with the closet wing beside it and a kitchen at the far end facing the wrong way. Infilling the side return and taking out the wing's flank wall turns three cramped spaces into one, and rooflights over the infilled strip put daylight exactly where the old plan had none. The structure is normally a goalpost of two beams and a column, an RSJ installation, with the existing rear wall opening to the garden usually a second, separate opening in the same scheme.

The mistake we see most often is glazing chosen before the structure is designed. A beam has depth, and if that depth was not allowed for it eats the head height above a sliding door, or forces a downstand across a ceiling meant to run flush. The new flat roof also needs a proper warm roof build up with falls to the outlet and insulation continuous over the beam, otherwise the junction between old and new becomes a cold line that attracts condensation in the first winter and mould in the second.

Clay, trees and what goes under the ground before the walls rise

London clay shrinks in dry summers and swells again in wet winters, and mature trees make that movement worse by drawing moisture out of the soil around their roots. Where a large tree stands near the plot, foundations for new build have to go deeper than the standard trench to reach unaffected ground, and the engineer sets that depth after a trial hole rather than from a rule of thumb. The existing house sits on much shallower footings, so the excavation next to it is dug in short bays to avoid undermining what is already there.

Drainage is the other underground surprise. Inspection chambers and gullies sit exactly where the new room wants to be, so runs get diverted, chambers relocated or replaced with sealed access covers, and a build over agreement is needed where the structure crosses a public sewer. Excavating close to a neighbour's foundation brings the Party Wall etc. Act 1996 into play, and the notice periods belong in the programme from the start of an extension job, not once the digger is booked. Building control inspects the open excavation before any concrete goes in, so that visit is arranged around the dig rather than after it.

Where to go next for work in Kew: house extensions in Kew, the Richmond upon Thames area guide, building work in Brentford, building work in Chiswick and Renovation Order of Works.