Refurbishing a flat in a Marylebone mansion block is a different discipline from refurbishing a house. In a house, the site is yours. In a block, the site is a room inside a functioning building where fifty other households are trying to live normally, the lift is shared, the corridor is shared, the services are shared, and a managing agent is watching. The building work is not harder. The conditions are.
The projects that go well here are the ones that treat the block as a stakeholder from day one. The ones that go badly are the ones that treat it as an obstacle. That is genuinely the difference, and it shows up in the programme, the cost and whether you are still welcome at the AGM.
The licence to alter is the start date
Most leases require freeholder or managing agent consent — usually a formal licence to alter — for anything beyond redecoration. Structural work, moving waste, altering the plan, changing floor construction and touching anything communal all typically qualify. Many Marylebone freeholds sit with large estates, and their licence requirements, conditions and timescales vary considerably, so the only reliable source is your lease and your own managing agent.
What a licence commonly involves is drawings, a written specification, your contractor's insurance details, and a review — sometimes by the freeholder's surveyor, at your cost. Conditions can be attached: hours, protection standards, acoustic performance, reinstatement obligations, and sometimes a deposit. None of this is unreasonable, and all of it takes time.
The practical advice is simple. Start the licence conversation before you start the design, not after. Design in the knowledge of what the lease permits, submit something the freeholder can say yes to, and treat the consent date as the start date. Building a programme that assumes consent will land on demand is the most common self-inflicted delay in this postcode.
Separately: if the block is running its own major works, leaseholder consultation under Section 20 of the Landlord and Tenant Act 1985 applies to works over £250 per leaseholder. That is the freeholder's duty rather than yours, but a communal programme colliding with your project affects scaffolding, access and the lift, so it is worth knowing what the block has planned.
The stock, and what it does to the work
Marylebone's mansion blocks are solidly built — masonry cross-walls, heavy floors, generous proportions, and thick plaster. Three consequences follow.
First, structure. Those cross-walls are frequently loadbearing, and the open-plan reconfiguration people arrive wanting is a structural project with a lease condition attached, not a demolition. Even where it is achievable, it needs engineering, freeholder consent and — because these are attached buildings — potentially notice under the Party Wall etc. Act 1996 for anything affecting a party structure.
Second, services routing. Solid construction means cables and pipes cannot simply be threaded through voids. Routes have to be found in existing conduit, existing chases, dropped ceilings, cupboards and later partitions, or accepted as perimeter solutions. This is covered in more depth on our Marylebone electricians page, and the riser and isolation side on Marylebone plumbers.
Third, capacity. These flats were serviced for a different century. The electrical sub-main feeding your flat, and the water pressure reaching it, may not support the kitchen and bathrooms you are planning. Upgrading either usually means engaging the freeholder and possibly a utility, and that is a weeks-long item. Establish capacity in the first fortnight or you will design something the building cannot feed.
Risers must stay reachable
Leases commonly require communal services to remain accessible. Every refurbishment here should include proper demountable access to any riser, stack or valve inside the flat — a removable panel, a section of cabinetry that comes out. It is invisible when done well, it satisfies the lease, and it means nobody ever has to cut through your new joinery to reach a pipe serving four flats.
Acoustics: the clause people wish they had read
Floor finishes are the most litigated subject in mansion blocks, and Marylebone is no exception. Most leases restrict hard flooring, require carpet in defined areas, or require a specified acoustic performance. Ignoring it is how people end up taking a floor up.
This matters at design stage because the acoustic layer is part of the floor build-up, and build-up drives thresholds, door heights and the level relationship between rooms. Decide the flooring and the acoustic solution before you finalise anything, not when the boards arrive. The same discipline applies to any plant you are adding — pumps, air conditioning, extract — because noise transmitted into a neighbour's flat is a problem you cannot fix afterwards without opening what you just built. Isolate it properly at the time.
Running a site inside a working building
Confirm your own block's rules, because they genuinely vary, but plan for something like this:
- Booking. Contractors named and booked with the porter or agent, insurance provided in advance.
- Hours. Restricted working hours, with a narrower window still for noisy work. This is a programme input — a strip-out limited to a few hours a day takes longer, and an honest quote says so.
- Lift. Service lift only for materials and waste, with proper lift protection fitted and maintained. Some blocks limit lift use to set times.
- Protection. Communal route protected — lift car, landing, corridor — before day one, cleaned daily, and left down for the duration.
- Communal areas. Nothing stored outside your front door. Ever. This is the rule that gets sites stopped.
- Waste. Bagged and collected to a timetable. Skips are rarely realistic and loading in Marylebone is difficult, so deliveries and collections are timed rather than casual.
- Neighbours. Told what is happening and when the noisy phase is. It costs nothing and prevents most complaints.
None of this is glamorous and all of it is why some contractors are welcome back in a block and others are not.
Georgian terraces and the Harley Street buildings
Marylebone is not only mansion blocks. There are Georgian terraces, many converted into flats decades ago, and the medical buildings around Harley Street. Both change the brief.
Converted terraces carry the legacy of the conversion. Services were improvised to reach stacks added after the fact, falls are often marginal, sound separation between flats is frequently poor because the conversion predates any meaningful standard, and the plan form is a compromise. Refurbishment is the moment to correct those things properly rather than re-cover them. Note also that many of these terraces are listed or sit within a conservation area — where they are, works affecting special character typically require listed building consent, and that is a separate regime from your lease. Check the position for your specific building rather than assuming.
Buildings in clinical use operate to different constraints again: work scheduled around consulting hours, no casual isolation of services, higher reinstatement standards, and dust and noise controls that a residential job would not need. Change of use between residential and clinical, in either direction, is a planning question and needs proper advice — not an assumption. If you are working on one of these buildings, tell us the operational constraint at the outset and the programme is built around it.
How the job is sequenced
Survey and capacity check first — structure, sub-main, water pressure, stack positions, floor construction, extract routes. Then design against what the lease permits, then the licence to alter, then block booking and protection. Then a single continuous programme: strip out, structure, first fix with every service coordinated while the fabric is open, substrate and acoustic layers, finishes, second fix, decoration, snag. Protection comes up last.
The one thing worth insisting on is that all services go in together while things are open. Opening and making good is the expense; the cable and pipe are not. A second campaign because the lighting control was decided late is avoidable money. Our wider approach is on the refurbishment page, and any bathrooms inside the project follow the block-specific route set out on bathroom refurbishment in Marylebone.
What to prepare
- Your lease — particularly the alterations and flooring clauses — and the managing agent's contact.
- The block's contractor rules, working hours and lift arrangements.
- Whether the building is listed or in a conservation area.
- What the block has planned for its own major works.
- Any drawings, previous licences or surveys.
- Photos of the flat as it is, plus the communal route in.
There is more on the local stock on the Marylebone hub, and agents managing property here should see working with estate agents. For contrast, the constraints on a refurbishment in Mayfair townhouse are heritage-led rather than block-led.
Price and how we work
Refurbishment is priced per quotation, because there is no honest starting number for a project whose scope is defined by your lease, your building and your brief. What we will do is be explicit about what drives it: the extent of the work, any structural content, the services and capacity position, the acoustic requirement, your specification, the licence conditions, and the access and noise restrictions the block imposes on the programme.
Before work begins you get a fixed quote against a defined scope, itemised so you can see exactly what is in it. If something behind a wall genuinely surprises us, you hear what it is and what it changes before we act, not afterwards. One point of contact runs the whole job — trades, the licence paperwork, the porter, the lift booking, the neighbour communication, the deliveries. In a mansion block that coordination is not administration; it is most of the project. Tell us about the flat and we will give you a straight view of what is involved and what it costs.