Guide
Renovating a mansion flat: lifts, risers and common parts
A purpose-built mansion block is not a large flat in a converted house. The building itself sets most of the terms.
Original risers decide the layout
Blocks of the 1890s to the 1930s were planned around service risers that carried soil and water vertically through the building, with kitchens and bathrooms arranged against them. Those risers are still where the drainage is, and they are usually shared with the flats above and below.
The practical consequence is that a layout is a negotiation with the stack rather than a blank sheet. Moving a WC or a sink any distance means finding fall that the floor build-up frequently cannot offer without work that steps outside a kitchen or bathroom instruction. An island in a mansion-flat kitchen is unusual for the same reason: the services will not reach it honestly.
You are working above someone's ceiling
Wet rooms in these blocks are stacked, so your bathroom floor is the neighbour's ceiling. Waterproofing is therefore specified as a documented system and tested before tiling, and the floor build-up carries an acoustic layer as well. Neither is an optional upgrade in this stock.
The same logic governs noise. Cutting and breaking carry through a solid structure far better than people expect, so noisy work is banded into hours the building has agreed and the neighbours have been told about.
Lifts, porters and common parts
A passenger lift in a period block will frequently not take a run of kitchen carcasses, a bath, or a full-height fridge. That is a measurement taken at survey, not an assumption: the lift car, the doorway, the turn at the top of the stair and the drop point outside all get recorded, because between them they decide what can be ordered.
Common parts are treated as part of the site. Dust screens, protected floors and an agreed route in and out are written into the method rather than offered as a courtesy. Many blocks have a porter, and a porter who knows what is arriving and when is the single most useful relationship on the job. Redecorating those common parts, though, is the freeholder's business and not part of a flat's instruction.
The paperwork runs ahead of everything
Almost every mansion flat is leasehold, so a licence to alter is the norm rather than the exception, and the managing agent will usually have standing rules about working hours, deliveries, waste and insurance evidence.
All of that belongs in the lead-in. The programme is written so consent and long-lead items resolve before the flat loses its kitchen or bathroom, which makes the start slower and the disruption shorter.
Questions
Occasionally, but drainage decides it rather than taste. Waste has to reach the original riser at a workable fall, and a long concealed run across a flat rarely finds it without lifting floors — which is a larger job than a kitchen instruction. Extract is the second obstacle, since a mansion-block elevation is not somewhere a new grille is assumed.
For a single kitchen or bathroom, often yes, provided dust can be isolated and there is an alternative for the room being worked on. For a whole-flat programme it is usually cleaner to decant: the sequence is faster, and living behind screens in a flat with one bathroom is harder than it sounds. We will say which after seeing the plan.
The work this applies to
Where this comes up
Related guides
- Licence to alter: kitchens and bathrooms in leasehold flats
Most flats in North West London are leasehold, and most kitchen and bathroom work in them needs the freeholder's written permission before anything is taken out.
- Tanking and waterproofing bathrooms on timber floors
In a converted house or a mansion flat your bathroom floor is somebody else's ceiling, and timber moves.