House renovation and refurbishment
from Hans Town to Rutland Gate

RBKC says that living in a conservation area does not prevent changes to a property, though houses there have stricter permitted development controls than elsewhere. Its Hans Town Conservation Area Proposals Statement was adopted on 17 January 2000, and the older statements stay in place until new conservation area appraisals replace them.

The statement says the Council normally resists additional storeys and takes a cautious approach to other roof alterations, and that, given the modest rear gardens, no rear extension should significantly infill a garden. On the street front, fanlights should never be panelled over or used for services such as flues, air conditioning units or security cameras; in the mews, garages should be retained rather than converted into living space. RBKC's Article 4 list includes Pont Street Mews, numbers 1-12 and 14-16 and Andros Cottage, under a direction starting 18 October 1988.

The Local Plan 2024, adopted on 24 July 2024, adds borough-wide policies: CD12 resists additional storeys on complete terraces with an unimpaired roofline and on buildings that already have one, CD13 resists rear extensions beyond the general rear building line of neighbouring extensions or rising to the original main eaves, and CD4 requires development to preserve or enhance the conservation area. In a conservation area an outline application is not enough; fully detailed applications are needed.

In Westminster, City Plan Policy 45 supports roof extensions in principle if heritage assets are not harmed, looking for one coordinated design across a terrace whose roofline is still unimpaired. Westminster's mini guide records an Article 4 direction at Relton Mews covering all external alterations, and its Article 4 page lists numbers 1, 4, 8, 11, 12 and 13.

Sources: Royal Borough of Kensington and Chelsea: conservation areas, Royal Borough of Kensington and Chelsea: Hans Town Conservation Area Proposals Statement (adopted January 2000), Royal Borough of Kensington and Chelsea: conservation area appraisals, Royal Borough of Kensington and Chelsea: Article 4 Directions in conservation areas, Royal Borough of Kensington and Chelsea: Local Plan, Royal Borough of Kensington and Chelsea: Local Plan (adopted July 2024), Westminster City Plan 2019-2040 (2026, adopted January 2026), Westminster City Council: Knightsbridge conservation area mini guide, Westminster City Council: Article 4 Directions in Westminster

The Trevor Estate holds the oldest houses on the Westminster side of Knightsbridge: its square and the streets around it were begun in 1813 and finished by the mid-1820s, Westminster's 2009 audit records. Montpelier Square next door shares much of that detail, but its houses are bigger and grander, at four storeys and a basement.

Most terraces rise three to five floors above a basement behind railed lightwells, built in yellow stock brick, stucco or half stucco, with a few faced in stone. The early houses carry gauged brick window arches, sashes of six panes over six and painted panelled front doors, and those are repaired in kind.

On the north side of Montpelier Square, the audit notes, many houses had their ground floors altered later, typically by shallow bays set where sashes once were. Where old photographs or neighbouring houses show the original pattern, a refurbishment can bring it back.

Mid-Victorian builders put their grander houses around squares or on streets named 'Gate' to suggest a link with the park, which at Rutland Gate never existed. Between those grand streets is a quarter of smaller artisans' houses and mews, ringed by the formal houses of Montpelier Square, Rutland Gate, Brompton Square and Brompton Road.

Embassies, institutions and flat conversions now occupy many of the large terraced houses. Turning one back into a family house means removing later partitions, lifts and services and restoring the plan of its principal floors.

The private communal gardens and the seven garden squares give the area its character, the audit says, so scaffold, skips and deliveries are kept to the street and never set against garden railings.

We record each sash, door and fanlight on the survey drawings before any work is priced, so the condition schedule, the consent drawings and the site instructions all refer to the same pieces.

Before choosing paint for a stucco front we take samples back to the earliest coat, because several layers of modern masonry paint can trap moisture in the render; where that has happened the paint is removed gently and the stucco allowed to dry out before it is repainted.

A house that served as an embassy or institution may carry heavy later services, such as secure doors or standby plant; we identify what can be removed safely and what the structure was altered to carry before any new layout is drawn.

Source: Westminster City Council: Knightsbridge, Knightsbridge Green and Albert Gate conservation area audit (SPD, adopted 20 April 2009)

In Kensington and Chelsea, Local Plan 2024 Policy CD11 limits basement development to a maximum of 50 per cent of each garden, with the untouched garden kept in a single area, and the plan limits depth to a single storey in most cases, generally about 3 to 4 metres floor to ceiling. Where a basement already has permission, has been built or was added under permitted development rights, no further basement floor is allowed.

CD11 also rules out excavation beneath a listed building, vaults included, and asks for at least a metre of soil over any part of a basement beneath a garden, a sustainable drainage system retained thereafter and a pumped device against sewer flooding; a non-return valve on its own is not acceptable.

The Hans Town statement notes that the River Westbourne still runs under its streets. A basement application in the borough must come with a construction method statement by a qualified civil or structural engineer, including a ground and hydrological report.

On the Westminster side, a city-wide Article 4 direction has removed permitted development rights for basements since 31 July 2016. City Plan Policy 50 supports basements that do not extend beneath more than half the garden land, asks for lightwells, plant, vents, skylights and means of escape to be sensitively designed and discreetly located, and supports no more than 1.8m of encroachment under the highway, with at least 900mm between the road surface and the vault. A structural methodology statement is required for every basement, and the plan strongly encourages consulting neighbours before applying.

The dig sets the site category too. RBKC's Code lists basement excavation or extension as Category 1, with minor basement extensions under 50 m3 of excavated material in Category 2, and Westminster's Code puts a project that is not Level 1 or 2 but builds or extends a basement at Level 3, with a Construction Management Plan.

Sources: Royal Borough of Kensington and Chelsea: Local Plan (adopted July 2024), Royal Borough of Kensington and Chelsea: Hans Town Conservation Area Proposals Statement (adopted January 2000), Westminster City Council: Article 4 Directions in Westminster, Westminster City Plan 2019-2040 (2026, adopted January 2026), Royal Borough of Kensington and Chelsea: Code of Construction Practice, Westminster City Council: Code of Construction Practice (May 2026)

We begin with a feasibility visit and a survey of the house, confirm whether the address is in Westminster or Kensington and Chelsea, read the list entry, the title and any lease, and identify the party walls the work will touch.

Our in-house architects prepare the planning and listed building drawings, our in-house structural engineers design structural and basement work, and independent surveying is available through our sister practice, Hampstead Chartered Surveyors & Building Consultancy. After a written quotation and the consents, site work follows the sequence set at design stage, so that structure and services are settled before any finishes go in.

I would like to thank Ross and his team for their consistent commitment to quality and their unerring reliability.

We have worked with Ross and his company many times. They are extremely professional and hardworking individuals who can work under any circumstances. There was no variation to the works.