Kensington is the borough where the below-ground rules bite hardest. A borough-wide Article 4 Direction removed permitted development rights for basements in 2016, so every below-ground project needs a full planning application with no fallback. Add the highest listed building density in the five, and the two constraints compound: what you can dig, and what you can touch once inside.
Conservation area coverage runs to over 70% of residential streets. The 2015 Basement Development Supplementary Planning Document limits most properties to a single-storey basement beneath the existing footprint, and a full planning application is required with no permitted development fallback.
RBKC’s determination period for a standard application runs eight weeks. Basement applications carrying a mandatory Construction Management Plan typically take twelve to sixteen weeks. Party wall timelines sit on top of that. Not within it. That distinction is where most Kensington programmes slip: the planning clock and the party wall clock are treated as though they overlap, and they do not.
Listed building density here is among the highest in London, and the consent covers more than the front of the building. Internal works to a listed property require Listed Building Consent for every original feature: cornices, fireplaces, floor joists, internal doors. Not just the facade.
That is the single biggest cost variable in the borough. A listed property in Kensington can cost 20 to 30% more than an unlisted one on the same street, because every material choice and every method needs conservation officer sign-off.
The Cadogan Estate covers part of the southern boundary between Kensington and Chelsea. If your property sits within it, a Licence to Alter is required before structural works begin, separate from RBKC planning permission. Review runs four to six weeks from a complete submission, and the licence covers structural and decorative changes alike. Completing works without it risks forfeiture of the lease.
Cadogan is the dominant landowner in Chelsea rather than here, so the full consent regime is set out on the Chelsea page.
RBKC enforces working hours of 08:00 to 18:00 Monday to Friday, and 08:00 to 13:00 on Saturday. No Sunday or bank holiday working. Construction Traffic Management Plans are mandatory on basement projects. Skip permits carry borough-specific charges and maximum placement periods.
Congestion Charge and ULEZ apply to every contractor vehicle here for the full duration of the programme, as they do across all five boroughs. What that costs over an eight-month run, and why it belongs in the preliminaries rather than in a variation, is set out on the Mayfair page.
Conservation area and basement policy compliance adds 15 to 25% to base costs against boroughs with fewer restrictions. Professional fees run higher because of the listed building and conservation area application load, since both consents need their own drawings and their own consultant time. Pre-construction adds 10 to 16 weeks before site start, and that period is work rather than waiting.
Typical programme 20 to 32 weeks. Pre-construction 10 to 16 weeks.
The 2016 direction is the one that removed permitted development rights for basements borough-wide. Other permitted development rights vary by street and by conservation area status, so the answer depends on the address. What is certain is the basement position: there is no permitted development route, whatever the property.
Often yes, but it needs Listed Building Consent, and the consent looks at every original feature rather than only the exterior. Cornices, fireplaces, floor joists and internal doors are all in scope. The question is not whether the work is internal. It is whether the feature is original.
The 2015 SPD limits most properties to a single storey beneath the existing footprint, so a garden extension to the basement is the exception rather than the norm. The application decides it, and the Construction Management Plan is mandatory either way.
Ten to sixteen weeks of pre-construction is typical, and a basement application with a Construction Management Plan sits at the longer end. Party wall timelines run on top of that, not inside it.
No. Conservation area status controls what the street sees, so external alterations need consent. Listing controls the building itself, inside and out. Over 70% of Kensington’s residential streets are in a conservation area, and a large share of those buildings are also listed. Many properties carry both.
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