A kitchen project in Knightsbridge is really three different projects, and which one you have depends entirely on what you own. If you hold a whole townhouse there is usually some ground behind it — often shallow, and reached from a garden or a lower-ground level, whichever your section actually shows — and a rear kitchen extension is genuinely on the table. If you hold a flat in a mansion block or a prime apartment building there is no rear ground to build into at all: the kitchen you want is a relocation and reconfiguration inside your demise, and what decides it is the communal stack, the structure you share with the flats above and below, and the terms of your lease. A mews house sits between the two, typically built hard to the street with little or nothing behind it. So we establish tenure, demise and physical envelope before drawing anything, because a Knightsbridge kitchen brief written for the wrong one of those three loses months.
Then the extract, which we settle before the layout rather than after it. A kitchen hood has to discharge somewhere, and given how extensive conservation-area coverage is across Knightsbridge, that somewhere is very often a protected elevation. The duct needs a route with enough straight length and few enough bends to move air at the rate the building regulations expect, a ceiling void or riser deep enough to carry it alongside the new structure, and a terminal that can lawfully exist where the drawing puts it. On a townhouse that generally means the rear wall or the new roof, in plain view of the backs of neighbouring buildings. In a block it means either an existing riser that will accept a kitchen duct, or a new penetration through the external fabric — and a managing agent may simply decline the latter, while the council will treat a grille cut into stucco or brick as an alteration to the building, not as a kitchen fitting. None of this is discoverable from a floor plan.
Waste is the second thing that quietly fixes the plan. A kitchen needs continuous fall from sink and appliances to a connection that will accept them, and in a mansion flat that connection is normally a communal soil and waste stack sitting outside your demise, shared with the whole column of flats. Whether a new kitchen waste can join it, and at what point, is a freeholder and managing-agent decision before it is a plumbing one, because grease entering a stack that serves other homes is a maintenance liability they will carry. The same conversation covers wet over dry: relocating a kitchen so it sits above a neighbour's bedroom or reception room is commonly resisted, and where it is permitted it arrives with a waterproofing and leak-detection specification attached. In a townhouse the run instead has to reach a gully in a rear yard or lightwell, and where a vault or a deep floor build-up lies in the way, levels, fall and waterproofing all have to be resolved on the same section.
Between flats, a kitchen is an acoustic and fire question as much as a spatial one. Appliances, a fan, a boiling tap and a hard floor all sit directly above somebody else's ceiling, and mansion-block leases and managing-agent schedules typically set out what the floor build-up must achieve for impact sound before consent is granted. The same requirements usually govern how a penetration through a compartment floor or wall is fire-stopped and how services may be routed through common parts. Opening up is where this becomes serious: a spine or party wall in a block is often carrying load from every flat above, so a new opening needs a structural design showing where that load actually goes, and in practice the freeholder's own engineer or building surveyor reviewing it alongside the council. We coordinate the structural information, the acoustic build-up and the fire-stopping into the Licence to Alter package rather than leaving them to be argued out on site.
On a townhouse the difficulties are different and mostly happen at the back. These houses were planned with a service floor at the bottom, so the kitchen usually wants to be at lower-ground level — and where that floor turns out to sit below the level of the yard or garden behind it, that single fact drives the extension: the threshold, the step out to the garden, the drainage fall, and the damp and waterproofing detail where new construction meets old vaulted or below-ground fabric all have to be worked out together on a section before any plan is credible. Where a scheme begins to involve lowering the floor or digging out beneath the house, it stops being a kitchen extension and becomes a below-ground project with its own tightly controlled regime, and we say so at the start rather than at the end. Foundations near a boundary bring the Party Wall etc. Act 1996 into play, on a timetable entirely separate from the planning decision.
The consent route then follows from the building rather than the other way round. We confirm whether the City of Westminster or the Royal Borough of Kensington and Chelsea governs your exact address, because the two apply different policies, conservation material and validation expectations to an identical kitchen proposal. We confirm the conservation designation and any Article 4 direction for that address rather than inferring it from the next street. We check the listing, the lease and the estate position, since listed building consent and a Licence to Alter can each sit in front of the council route. Then we survey, fix the extract, the plant and the drainage against what the building will physically accept, prepare the planning and heritage drawings, and produce the building regulations package. We do not promise approval; what we do is remove the reasons a scheme would be refused.
