Marylebone W1U · Houses, flats & bathrooms
Georgian terraces, mansion blocks, mews and lightwells
Our Hampstead team plans house, flat, kitchen and bathroom work across Marylebone. The Harley Street and Portman Estate conservation areas take in the two estates' street grids, a very large proportion of the Portman area's 18th-century buildings is listed Grade II, and a flat's lease may make alterations subject to the landlord's permission, so every brief begins with the address.
Serving Marylebone from our Hampstead studio · NW3 6DN
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01 Mansion blocks and estate flats
Mansion blocks replaced parts of the northern Portman Estate streets in the late 19th century, and the estate says modernising a flat may need approval from both the immediate landlord and the freeholder.
Sources: Westminster City Council: Portman Estate conservation area mini guide, The Portman Estate: licence to alter
Read about flat renovation02 Townhouses on the estate grid
Portman Estate houses are ranked first, second or third rate by the street they face, and in the Harley Street area almost every surviving first-phase terrace in near-original condition is listed.
Sources: Westminster City Council: Portman Estate conservation area mini guide, Westminster City Council: Harley Street conservation area mini guide
Read about house renovation03 Kitchens in period houses and flats
In a listed house, the City Plan's Policy 44 looks to protect original or significant detail and old fabric, so extract and drainage runs are planned around them.
Source: Westminster City Plan 2019-2040 (2026, adopted January 2026)
Read about kitchen renovation04 Bathrooms, showers and WCs
Leases commonly expect carpet, the Portman Estate notes, so tiles may need a licence, while a like-for-like swap of bath, WC, basin or sink is exempt from building regulations approval under gov.uk guidance.
Sources: The Portman Estate: licence to alter, GOV.UK: when you don't need building regulations approval
Read about bathroom renovation05 Bookcases and dressing rooms
Bookcases, dressing rooms and window seats are drawn to the room and built by our joinery team.
Read about bespoke joineryThe buildings
Many of Marylebone's terraces belong to two planned estates. The Portman Estate laid out Portman Square in 1764 and carried its 18th-century grid to Manchester Square in 1776 and to Baker Street, completed around 1800; Westminster first designated the Portman Estate Conservation Area in 1967 and extended it in 1979 and again in 1990, when Portman Square was added. The Harley Street Conservation Area dates from 1968, when it was drawn around Portland Place, Harley Street and Wimpole Street; it reached west to Marylebone High Street in 1981 and covers the Howard de Walden Estate's Marylebone grid.
Westminster's 2004 guide to the Portman Estate says its houses mirror the hierarchy of the plan: first and second rate on the main roads and squares, third rate on the side streets, generally stock brick with modest stucco, though corner houses on Montagu and Bryanston Squares use stucco more extravagantly. Parts of the northern streets were rebuilt with mansion blocks in the late 19th century. In the Harley Street area the original plot widths of the terraces are still discernible, and buildings rarely exceed six storeys.
Listing is dense. The Portman Estate area has about 600 listed buildings, mainly on Bryanston, Montagu and Manchester Squares, Great Cumberland Place, Gloucester Place, Manchester Street, Wyndham Place and York Street, and the Harley Street area has two Grade I buildings, All Souls Langham Place and Chandos House, 33 at Grade II* and about 260 at Grade II.
Homes in the Harley Street area share their streets with medical uses of international renown around Harley Street itself, and with Marylebone High Street, the area's main shopping thoroughfare. Its boundary meets the Regent Street, Mayfair, Portman Estate, Regent's Park and East Marylebone conservation areas.
Sources: Westminster City Council, Portman Estate conservation area mini guide (May 2004), Westminster City Council, Harley Street conservation area mini guide (May 2004), Westminster City Council: Portman Estate conservation area mini guide, Westminster City Council: Harley Street conservation area mini guide
Consents and policy
Its licence-to-alter FAQ says a structural alteration that changes how a property looks could require planning permission and building regulations approval on top of a formal licence, and that, depending on the lease, structural work can leave the leaseholder paying the estate's solicitors' and consultant structural engineers' fees, with a premium possibly payable.
Source: The Portman Estate: licence to alter
Under City Plan Policy 44, works to a listed building will preserve its special interest, protecting or, where appropriate, restoring original or significant detail and historic fabric. City-wide, the council records upwards of 11,000 listed buildings and structures, of which over 200 are Grade I.
Source: Westminster City Plan 2019-2040 (2026, adopted January 2026)
Bryanston, Manchester, Montagu and Portman Squares, and Cavendish Square in the Harley Street area, all fall under the London Squares Act 1931. Portman Square and Manchester Square are also Grade II registered historic parks and gardens.
Sources: Westminster City Council: Portman Estate conservation area mini guide, Westminster City Council: Harley Street conservation area mini guide
The strategic view from Primrose Hill to the Palace of Westminster passes over the Harley Street area between Park Crescent and Oxford Street. The Marylebone Village archaeological priority area lies largely within it, around the north end of Marylebone High Street, and the Tyburn Settlement priority area affects its south-west part.
Sources: Westminster City Council, Harley Street conservation area mini guide (May 2004), Westminster City Council: Harley Street conservation area mini guide
Policy 45 backs a roof extension in principle so long as heritage assets suffer no adverse impact. Where a terrace's roof line has not yet been broken by extensions, it asks for a coordinated approach, with the same design repeated along the terrace.
Source: Westminster City Plan 2019-2040 (2026, adopted January 2026)
A city-wide Article 4 direction has removed permitted development rights for basements since 31 July 2016, and the City Plan's basement policy, Policy 50, backs schemes that leave at least half of the garden land without a basement beneath it. Westminster's 2004 Portman Estate guide recorded no Article 4 directions for that conservation area; the council now lists eight conservation areas where it has removed permitted development rights.
Sources: Westminster City Council: Article 4 Directions in Westminster, Westminster City Plan 2019-2040 (2026, adopted January 2026), Westminster City Council: Portman Estate conservation area mini guide
Before design
LEASE advises that some leases make alterations conditional on the landlord's permission, whatever planning or building regulations approval says, and that a clause insisting on carpet can rule out wood or laminate floors.
Source: LEASE: alterations and home improvements
A very large proportion of the Portman Estate area's 18th-century buildings is listed Grade II, and in the Harley Street area almost all surviving first-phase terraces and houses in anything like their original condition are listed. City-wide, Westminster has 56 conservation areas, together covering 78% of its area.
Sources: Westminster City Council: Portman Estate conservation area mini guide, Westminster City Council: Harley Street conservation area mini guide, Westminster City Plan 2019-2040 (2026, adopted January 2026)
Policy 50 supports basements that reach no further than 1.8m under the highway and keep 900mm or more between the road surface and the vault, with lightwells, plant, vents, skylights and means of escape sensitively designed and discreetly placed. A structural methodology statement goes with every basement application, and a flood risk assessment too where the site is in flood zone 2 or 3 or a surface water hotspot.
Source: Westminster City Plan 2019-2040 (2026, adopted January 2026)
If the work falls under the Party Wall etc Act 1996, gov.uk explains, the building owner serves notice on adjoining owners as the Act prescribes, and the Act sets out how disputes are settled. The council asks all developers and contractors to keep to the intent of its construction code: the hours, keeping impact down, informing neighbours and reporting incidents.
Sources: GOV.UK: Party Wall etc. Act 1996 guidance, Westminster City Council: Code of Construction Practice (May 2026)
Site rules
Westminster's building day is 8am until 6pm on weekdays and 8am until 1pm on Saturdays, and the council's construction code sets quieter limits for every Saturday activity. Noisy work on a Sunday or bank holiday needs special permission, and noisy work outside the set hours needs prior consent under section 61 of the 1974 Control of Pollution Act.
Sources: Westminster City Council: noise problems we can investigate, Westminster City Council: Code of Construction Practice (May 2026)
The council lets you apply to suspend a bay for a skip delivery or building works, with 10 working days' notice, and charges a short-notice fee when the request lands within 10 calendar days of the start. Scaffolding, hoardings and any skip left in the road each need their own licence before work begins, and vaults and other structures below ground are considered before skips or heavy equipment go over them.
Sources: Westminster City Council: parking bay suspensions, Westminster City Council: Code of Construction Practice (May 2026)
Basement work puts a project into the code's Level 3, with a Construction Management Plan, unless it already sits in Level 1 or 2. Level 4 jobs carry no formal requirement to agree working practices with the council but are meant to follow the code's principles, and one can be moved up to Level 3 where local environmental sensitivity or cumulative impacts justify it.
Source: Westminster City Council: Code of Construction Practice (May 2026)
Questions before you begin
Check the full address: two conservation areas cover the estate grids. The Harley Street Conservation Area, dating from 1968 and enlarged to take in Marylebone High Street in 1981, covers the Howard de Walden Estate's grid; the Portman Estate Conservation Area, first designated in 1967, covers the late 18th and early 19th century streets the Portman Estate developed.
Sources: Westminster City Council, Harley Street conservation area mini guide (May 2004), Westminster City Council, Portman Estate conservation area mini guide (May 2004)
It may. Its licence-to-alter FAQ says a tenant modernising a flat may need approval from the immediate landlord and the freeholder, and that air conditioning or a satellite dish on the roof may need a licence from both, depending on the lease.
Source: The Portman Estate: licence to alter
A fee is payable when you apply, set by the nature, extent and cost of the work.
Source: The Portman Estate: licence to alter
The documents then go to the council at least 40 working days before work is due to begin.
Sources: Westminster City Plan 2019-2040 (2026, adopted January 2026), Westminster City Council: Code of Construction Practice (May 2026)
A Marylebone project is priced around the estate and the building. Consents from the Portman or Howard de Walden estates, Westminster's controls on listed interiors and Article 4 streets, a lease on a mansion flat, and the Code of Construction Practice's limits on hours and parking suspensions all change the scope. We cover these at a feasibility visit, agree a scope and specification, and supply a written quotation.
The same team stays with the project from the first visit to handover. Our in-house architects, designers and structural engineers draw and specify the work. Master joiners make the fitted furniture. Building Regulations approval comes from the building control body appointed for the project. Independent surveying is a separate appointment: Hampstead Chartered Surveyors & Building Consultancy, our RICS-regulated sister practice, is a separate firm that a homeowner instructs directly. One JCT contract covers the building work. Electrical and gas work is carried out by appropriately registered engineers. Completed structural work carries a 12-month aftercare/defects period. Cover is £5M public liability, £10M employers' liability and contractors' all risks cover. Main office: 250 Finchley Road, Hampstead, London NW3 6DN. Central London client consultation address: 2 Eaton Gate, Belgravia, London SW1W 9BJ. Telephone 020 7101 3168.
Licence to alter · Independent surveying by our sister practice
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Describe the property and the work in our project planner. A quotation follows a review of the property and the specification.
Our work in Marylebone: Marylebone home refurbishments, and Wimpole Street, W1G, an apartment renovation with herringbone parquet flooring and a bespoke walnut kitchen.
