A Holborn kitchen project begins with a fact most rear-extension advice ignores: there is usually nowhere to extend. The flat's outline is fixed by the building around it, so the gain comes from moving the kitchen within the plan — freeing a reception room, borrowing from a hall, or turning a cellular galley into an open kitchen-dining space. That makes the governing constraint the position of the existing soil stack rather than a garden building line. Every fixture that drains — sink, dishwasher, washing machine, and any new utility point — has to reach that stack at a workable gradient, so before a layout is agreed we map where the stack rises through the building and how far a new kitchen run can travel from it while still draining reliably by gravity.
Drainage falls are where kitchen relocations in mansion blocks succeed or stall. Waste from a sink or appliance needs a consistent fall back to the existing stack, and the further the kitchen moves from that stack the more floor depth the pipe run consumes to keep its gradient. In an older flat with limited void below the finished floor, that depth may not exist, and the honest answer is sometimes a pumped or macerating solution rather than a longer gravity run — a compromise with its own maintenance and noise implications that the client should choose with eyes open. We test the drainage route at feasibility, because it quietly decides how far across the flat the kitchen can actually go before the design is committed.
Cooker extract is the second services problem, and in a Holborn flat it is rarely simple. A ducted extract has to terminate somewhere, and the honest options are a shared riser — if one exists and the freeholder permits its use — or an external face, which brings the exterior, and therefore possible planning and conservation questions, into play. Where neither is available a recirculating system is the fallback, but it does less and needs the layout to allow for filter maintenance. Risers in these buildings are constrained, often shared with other flats and other services, and their spare capacity cannot be assumed. We establish what the riser can carry, and who controls it, before designing the extract rather than after.
The floor is the third technical front, and it points downwards. Relocating a kitchen usually means opening up the floor to run new services, and that is the moment to build up its acoustic construction over the flat below. Kitchens generate impact noise — footfall on hard finishes, appliances, dropped items — and leases in mansion blocks frequently carry obligations about floor coverings and sound transfer to the flat beneath. A resilient floor build-up, a floating layer or an isolated finish can address that, but it adds height that has to be reconciled with the drainage falls competing for the same depth. We coordinate the acoustic layer and the waste runs together, because on a flat floor they are fighting over the same few centimetres.
Tenure is the frame around all of it. A Holborn flat is almost always leasehold, so the freeholder and, in a managed block, the managing agent have to consent to the work through a Licence to Alter before it can lawfully proceed. That consent typically scrutinises exactly the things this kind of kitchen move touches: alterations to structure, changes to drainage and services, acoustic performance to neighbours, and the use of shared risers and common parts. Any wall being removed to reconfigure the kitchen has to be confirmed as non-structural, or engineered and consented if it is not, and cutting into a party floor or wall can bring the Party Wall etc. Act 1996 into play between the flats involved. We prepare the drawings the licence needs alongside the technical package.
The route we run reflects those realities in order. We survey the flat and locate the stack, the risers and the structure; we test the drainage and extract feasibility so the layout is built on what the services can actually do; then we develop the design and produce the Licence to Alter drawings and the building regulations package together. Because Holborn is a dual-authority area, if any external element does need consent we confirm whether Camden or the City of London applies for the exact address before making a submission. We do not promise approval or that a freeholder will grant a licence — both sit with others — but we set the scheme up to be assessed on its merits, technically resolved and honest about its constraints.
Coordination between trades and consents is what keeps a flat kitchen from stalling mid-build. The drainage run, the extract route, the acoustic floor and the electrical works all share the same limited voids and the same programme, and in a mansion block they also share access, hours and protection rules set by the building's management. Sequencing them on the drawings — rather than discovering the clash when the floor is already open — is where the design work earns its place. We identify the notifiable neighbours for any party-structure work early, agree the licence scope with the freeholder's surveyor, and hand the builder a package that reflects the real building, so the kitchen the client signed off is the kitchen that gets built.
