Measure the room in use
The first bathroom drawing includes the space occupied by a person, not just the fixtures. We check entry, turning, towel access and the position from which the shower controls can be reached. A larger basin can make a narrow room harder to use, while a different door arrangement may improve it without moving the plumbing. The brief records who uses the room, what currently causes difficulty and whether future changes in mobility should influence the layout now.
We also inspect what sits outside the bathroom. A raised floor can create an awkward threshold, a cabinet can project into a landing, and a door can obstruct another room. In a compact apartment these relationships deserve attention before the sanitaryware order. We compare layouts with the existing structure and drainage connection shown clearly. This prevents a persuasive image from concealing a pipe route or floor build-up that has not yet been resolved.
Separate the room refit from changes to the building
The Corporation's residential guidance warns against applying householder assumptions to flats. For a bathroom, external ventilation, changed glazing or another alteration to the envelope needs a specific check. We describe those elements individually when identifying the approval route. There is a meaningful difference between replacing fittings within an established room and creating a new outlet through a shared external wall; the specification should make that distinction visible from the start.
For listed property, work affecting special character needs listed-building consent. That can involve internal fabric as well as the exterior. Before covering an old wall or changing an opening, we record what is present and ask how the proposal affects it. The design can then consider positions and fixing methods that reduce unnecessary disturbance. An attractive bathroom scheme is incomplete if the construction method has not accounted for the historic building in which it will sit.
Sources: City Corporation: residential planning permission · Historic England listed-building consent
Design a continuous water-management system
We examine the relationship between the shower area, the surrounding floor and the doorway. Waterproofing is specified as a coordinated system with compatible junctions, penetrations and substrates, rather than as a final product applied after other decisions have been made. The installer needs clear information about corners, changes of material and connections to the chosen tray or drain. Details hidden beneath tiles receive attention before they are concealed, because the decorative surface alone does not establish the performance of the assembly.
Waste connections are checked for their route, level and accessibility. Where the existing arrangement is uncertain, investigation is identified before the proposed fixture position becomes fixed. We avoid promising a level shower simply because it appears on a drawing; available depth and the complete drainage design must support it. Valves, traps and concealed fittings also need a maintenance strategy. A removable panel is useful only if it gives enough access to the component that may need attention.
Balance air, light and practical storage
Ventilation is reviewed with the room's use and the building's existing arrangements. We establish whether a proposed fan connects to an individual outlet or interacts with a shared system, and seek the relevant information before altering it. The control arrangement should be understandable to the person using the room. A quiet-looking grille is not a substitute for a suitable system, and boxing around a duct must be included in the measured layout rather than appearing unexpectedly during fitting.
Lighting needs vary between the mirror, the shower and the route into the room. We coordinate fittings with the electrical installer and the room conditions, while reviewing glare from the user's normal position. Storage is drawn around toiletries, cleaning supplies and spare towels, with appropriate clearance near water and heat. Finishes are assessed for cleaning and the intended use as well as appearance. Sample tiles are considered with grout, edges and adjacent materials, not as isolated squares.
Check installation before and after concealment
The work sequence includes opportunities to review the prepared floor and walls, the service connections and the waterproofing details before the visible finishes go on. We record decisions about deviations from the original layout so that the final installation is understandable. If an existing condition prevents the specified detail, it is resolved with the relevant designer or installer before proceeding. Substituting an improvised arrangement beneath a finished surface makes both checking and future maintenance harder.
The final review covers drainage operation, fixture movement, access panels, surface junctions and the operation of the agreed controls. We also look at the room from the doorway, checking alignment and transitions to the adjoining floor. The owner receives the relevant product and care information and an explanation of accessible service points. Any remaining item is recorded clearly. A bathroom should be handed over as an intelligible working installation, with its hidden decisions documented as well as its surfaces cleaned.
Before work begins
Bathroom renovation in City of London: questions
Can the WC be moved to the opposite wall?
Possibly, but its drainage connection must be investigated first. We assess the route, available levels and effects on the room and neighbouring spaces. The feasibility drawing should show the actual service arrangement, including any boxing or floor changes, before the new position is agreed.
Is a walk-in shower always possible in a flat?
No. The floor construction, drainage depth and waterproofing design may limit a level arrangement. We assess those conditions and discuss suitable alternatives. Accessibility is considered through the whole route into and around the room, including its threshold and the position of controls.
Do listed interiors need a separate check?
Yes. Listed-building consent concerns alterations affecting special architectural or historic character, which may include internal features. We identify what the bathroom work would change before selecting removal or covering methods. The absence of a feature from a short listing description is not clearance to remove it.
How can concealed plumbing remain serviceable?
The specification identifies access to valves, traps and other maintainable components. Panel positions and opening sizes are coordinated with cabinetry and tiles. We check that the component can actually be reached and removed, rather than adding a small inspection opening that provides little practical access.
What is reviewed before choosing tiles?
We establish the layout, substrate, floor levels, drainage and waterproofing approach first. Tile thickness, format and edge details can then be coordinated with those decisions. Lighting and grout samples are reviewed alongside the tiles so that the complete surface treatment is understood before installation.
Official sources
City Corporation: residential planning permission · Historic England listed-building consent
Sources checked on the dates recorded in the source register, most recently 5 November 2026. Maps, list entries and directions must be checked for the individual property and proposed work.