House renovation and refurbishment
for Mayfair's town-houses and mews

On the Grosvenor Estate, the estate management schemes require Grosvenor's consent, on top of the statutory permissions, for certain changes. Grosvenor sums the schemes up as largely concerned with external load-bearing structure, its repair and alteration, and with how outside surfaces are decorated; only in Belgravia do they extend to alterations of internal load-bearing structures.

The works it lists as needing consent are extensions, basements included; replacing or altering windows; works to walls and roofs, external pipework among them; roof terraces; and air conditioning, comfort cooling or other external plant. A basement needs consent even though, once built, it leaves the look of the house unchanged.

Grosvenor is strict about the colour and type of paint used on the outside. It wants a roof terrace kept for occasional enjoyment, not turned into a permanent outdoor room, and it can stagger or hold back approval to spare nearby occupiers needless disruption, with mews singled out. Fitting a new kitchen, bathroom or cupboards that reuse the existing plumbing, electrical and gas connections needs no Grosvenor consent.

The guide is addressed to freehold owners, and Grosvenor's consent is one permission among several: Westminster's planning permission and listed building consent are separate applications.

Source: Grosvenor: Belgravia and Mayfair management schemes

Westminster's Article 4 direction, in force since 31 July 2016, takes away permitted development rights for basement development throughout the city, so a new basement needs a planning application. City Plan Policy 50 supports one that extends beneath no more than 50% of the garden land, or, where the garden is no longer than 8m, reaches up to 4m from the original building in that direction, and that leaves at least one metre of soil plus a 200mm minimum drainage layer above it.

The plan's preferred basement is a single storey, roughly 2.7m from floor to ceiling, set below the lowest part of the original floor level; large sites able to house plant and machinery, with construction access that will not harm neighbours, may justify an exception. In a listed building the basement should not unbalance the original hierarchy of spaces where that contributes to significance, and lightwells, plant, vents, skylights and means of escape should be discreetly placed.

Beneath the pavement, Policy 50 supports encroachment of no more than 1.8m under the highway, with at least 900mm between the road surface and the vault. Every basement needs a structural methodology statement and a signed Appendix A of the Code of Construction Practice with the application; a site in flood zone 2 or 3 or a surface water hotspot also needs a flood risk assessment, and the council strongly encourages talking to neighbouring occupiers before applying.

Grosvenor's guide adds its own limits: a basement storey no deeper than 3.0m from the top of the slab to the underside of the structural ceiling, digging below floors already beneath street level generally not permitted unless their floor-to-ceiling height is under 2400mm, and basements generally discouraged in mews houses. Near Oxford Street, the Tyburn Settlement area of special archaeological priority runs 100m south of it from Binney Street to Woodstock Street.

Westminster's construction code puts a project that is not Level 1 or 2 into Level 3 if it builds a new basement or extends one, of any scale, and a Level 4 project can be raised to Level 3 where local environmental sensitivity or cumulative impacts justify it.

Nothing, site preparation included, starts until that plan is approved in writing, Appendix A is signed off and the planning condition is discharged. Without a Section 61 consent, the contractor is served a Section 60 notice setting working hours, and demolition, excavation and piling stay off Saturdays unless special permission is granted.

Sources: Westminster City Council: Article 4 Directions in Westminster, Westminster City Plan 2019-2040 (2026, adopted January 2026), Grosvenor: Belgravia and Mayfair management schemes, Westminster City Council: Mayfair conservation area mini guide, Westminster City Council: Code of Construction Practice (May 2026), Westminster City Council: noise problems we can investigate

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.