Flat
refurbishment
in St James's, SW1
Architects, Engineers, Surveyors & Builders Under One Roof.
One Studio. One Contract. One Team.
Hampstead Chartered Surveyors & Building ConsultancyFlats in St James's are found in the later mansion blocks, which the audit says keep the proportions of the older facades, and in the side streets where most of the area's homes are. Each refurbishment is planned around its lease and any listing.
St James's residential character sits above its famous ground floor, and a flat refurbishment here is led firmly by consents and logistics. Its homes are largely mansion flats, period chambers and upper-floor conversions — many listed, above the galleries, clubs and shops — where structure, acoustics and managing-agent consents are central to the work.
The controls are among the tightest anywhere. St James's sits within its conservation area on the historic streets between St James's Park and Piccadilly; Westminster scrutinises external change exceptionally closely, much of the area is listed, and the prestige mixed-use ground floor and tight streets shape every project. Jermyn Street and King Street carry period buildings with flats and chambers above, while Duke Street and the streets towards Pall Mall add mansion flats and upper-floor conversions.
A site assessment, agreed scope and specification are needed before the work can be quoted.
Retained interiors and shared building services
For a St James's apartment, survey the retained plasterwork and doors alongside the existing service routes. Coordinate kitchen and bathroom positions with the floor construction and lease conditions, and measure the delivery route through any shared entrance or staircase.
Refurbishing a flat in a shared St James's building
A St James's flat may be in a later mansion block or a converted older building, and Historic England lists Albany Courtyard, within an enclave Henry Holland converted into apartments, so check whether the building itself is listed. Many residential properties here have passed to commercial use, the audit records, so learn who occupies the floors around yours.
Source: Historic England: Albany Courtyard, Nos 1 to 6, Piccadilly, Grade I · St James's conservation area audit SPG, adopted 27 November 2002
Open a section of floor to see how it is framed before choosing stone or removing a partition, and ask an engineer which walls carry load. Design acoustic layers and floor build-up together under Approved Document E, since the household below lives with whatever the new floor transmits.
Source: When Building Regulations approval is needed · GOV.UK: Approved Document E, resistance to sound
Survey each window before choosing between repair, draught-proofing, secondary glazing and replacement. Westminster is clear that flats have no permitted development rights, so new frames need a planning check, may fall under Building Regulations and can meet terms in the lease. Treat a new vent, flue or plant that would alter a listed or visible elevation the same way.
Source: Westminster: permitted development rights · When Building Regulations approval is needed · LEASE: alterations and home improvements · Historic England: listed-building consent
Permissions to check for a St James's flat
Read the lease's alterations clauses before the layout is fixed: they can attach conditions to floors, services, windows and how the work is done, not only require the landlord's written consent. That private consent sits beside Westminster's controls and Building Regulations without answering either.
Source: LEASE: alterations and home improvements · When Building Regulations approval is needed
Internal work in a flat is generally not development, but combining two flats is a planning matter, and City Plan Policy 12 sets conditions before a home that is not family-sized can be absorbed into another. If the building is listed, consent can reach panelling, partitions and floors inside the flat, and unconsented work is a criminal offence.
Source: When planning permission is required · City Plan 2019–2040 (2026), adopted 21 January 2026 · Westminster: listed buildings and listed building consent · Historic England: listed-building consent
Building Regulations approval can apply to new bathroom plumbing, wiring near a bath or shower, replacement windows and heating, through Westminster's building control or a competent-person scheme. Check whether the block reaches the height at which most building work needs Building Safety Regulator approval instead, and whether cutting into a wall shared with a neighbouring building needs Party Wall Act notice.
Source: When Building Regulations approval is needed · GOV.UK: Building Regulations approval · Westminster: building control applications · Party-wall work requiring notice
Working inside a shared St James's building
Agree with the building manager how the shared entrance, stair and lift will be protected, and photograph them before the first delivery. Historic fixtures are at risk during works, the City Plan warns, and anything damaged or stolen must be reinstated, so keep shared panelling and staircases covered.
Source: LEASE: alterations and home improvements · City Plan 2019–2040 (2026), adopted 21 January 2026
Westminster permits audible building work from 08:00 to 18:00 on weekdays and 08:00 to 13:00 on Saturdays, when stricter noise thresholds apply, and none on Sundays, bank holidays or public holidays. A lease or the block's rules may narrow those hours, so check both before booking strip-out, and brief the occupiers around the flat.
Source: Westminster: construction noise and permitted hours · LEASE: alterations and home improvements
If rubble will leave by skip, Westminster requires a skip licence, and a skip in a parking bay or on a yellow line also needs a suspension or dispensation booked in advance. On a red route, such as the Hyde Park Corner end of Piccadilly, TfL issues highway licences, so check its map for the building's frontage.
Source: Westminster: skip licences · Westminster: parking bay suspensions · TfL: red routes and the TLRN map · TfL: highway licences on red routes
What to gather for a St James's flat quotation
Give the full address, the flat's floor and how it is reached, and whether it sits in a mansion block or a converted building. Photograph every room, the shared hall and stair, and any stains or leaks on ceilings, so the surveyor knows which shared pipes to examine.
Send the lease, any house rules for the block, the landlord's or managing agent's requirements for works and whatever drawings you hold. Add earlier decisions on planning, listed building consent and building control, and say whether the building is listed or in a conservation area, if known.
Source: LEASE: alterations and home improvements
Separate settled decisions, such as known repairs and chosen finishes, from items awaiting opening up or an engineer's view, so a quotation can carry those as provisional sums. Agree who seeks the landlord's consent, makes each application and books inspections, and whether you will stay in the flat.
What does a flat refurbishment cost in St James's?
A written scope and site assessment are needed before any project price can be fixed.
Guide rates exclude VAT and are set by depth of work, not by property type. Compare scopes in our London refurbishment cost-per-square-metre guide.
Flats in St James's: mansion blocks, converted houses and listed modern buildings
Many St James's flats are in the later mansion blocks that, the audit says, continue the proportions and materials of the older terraces. Some are in listed post-war buildings: the audit names the eight-storey Lasdun flats on St James's Place among the modern buildings listed for their architectural and technological interest.
Homes sit mainly in the smaller side streets, and above all in the west of the area, in the buildings backing onto Queen's Walk. A flat may share its building with offices, clubs or hotels, which shapes delivery times, noise and access long before the design does.
Before any drawing, we read the lease. LEASE notes that a landlord's consent may be needed even where planning permission exists, and that clauses can restrict specific work, such as a ban on cutting external walls, which would stop new openings for pipes, or a requirement for carpeted floors, which can rule out timber flooring.
We check whether the building is listed before any internal change is drawn, and in a listed building we treat plasterwork, joinery and the plan of the rooms as part of the brief rather than as finishes to be replaced.
Where a flat sits above or below offices, we test the existing floors for sound and plan the new floor build-up so that a hard finish does not weaken the separation the building relies on. Noisy work keeps to Westminster's hours, weekdays from eight until six and Saturdays from eight until one, and a bay suspension for deliveries needs 10 working days' notice.
On Queen's Walk, the audit describes a more varied frontage forming a transitional zone between the core of the conservation area and Green Park, so any change to windows on that edge is judged against one of its most visible frontages.
The audit finds the area's buildings, whatever their date, largely unaltered in the ways that shape its character. At the first visit we record surviving cornices, shutters, panelling and doors, and keep them unless the client decides otherwise and consent allows.
Shared risers, the water supply and the building's fire separation are agreed with the building manager before kitchen and bathroom positions are fixed.
Buildings in the main body of the area are usually five or six storeys, the audit says, with buildings of up to eight storeys, mansards included, along the principal routes. A flat high in one of these buildings relies on a shared lift and stair for every delivery, so access, protection of the common parts and the hours of noisy work are agreed with the building manager in writing. We photograph the common parts before work starts and again at handover, so any question of damage is easy to settle.
Later flats can be listed too: Westminster's audit names the Lasdun flats in St James's Place alongside New Zealand House and the Economist group. In a listed block, internal changes to a flat may need listed building consent, so the list entry is read before the layout is drawn.
Many good original railings survive, the audit adds, especially in streets off St James's Street such as Park Place. In a converted house the railings and lightwell belong to the whole building and stay protected while materials are carried in.
The closest related case study is outside St James's: Rutland Court, Knightsbridge, an apartment interior refurbishment in Knightsbridge with a bespoke kitchen.
Sources: Westminster City Council: St James's conservation area audit (SPG, adopted 27 November 2002); LEASE: alterations and home improvements; Westminster City Council: noise problems we can investigate; Westminster City Council: parking bay suspensions.
Flat Refurbishment in St James's: Questions
What kind of homes are refurbished in St James's?
Largely mansion flats, period chambers and upper-floor conversions, many of them listed and set above the famous galleries, clubs and shops — so refurbishment here is led by consents and logistics rather than by the finishes alone.
Is St James's in a conservation area?
It is, and a strict one. St James's sits within its conservation area on the historic streets between St James's Park and Piccadilly, Westminster scrutinises external change exceptionally closely, and much of the area is listed.
How much does a flat refurbishment cost in St James's?
Listing, the lease and restricted access then set the figure.
What drives the budget on a St James's flat?
Estate and leasehold coordination, party-wall awards, protected facades, restricted access and careful temporary works, plus structural openings in older townhouses and the level of detailing expected around SW1 mansion flats and historic streets.
Which St James's streets do you work on?
Jermyn Street and King Street carry period buildings with flats and chambers above the shops and galleries; Duke Street and the streets towards Pall Mall add mansion flats and upper-floor conversions in a strictly-protected setting.
