Planning & Conservation in Kensington & Chelsea

1. Confirm CA, Article 4 and basement implications early

Roughly three-quarters of RBKC lies in conservation areas across many designations. A borough-wide Article 4 removing basement PD rights came into force on 28 April 2016. Front elevation and hardstanding Article 4s are also common on specific streets — check the address, not the neighbourhood brand.

2. Test feasibility against basement and amenity policy before sketching “maximum dig”

RBKC’s basement policy approach restricts basement development in scale — including limits commonly summarised as single storey and not more than 50% of each garden or open part of the site under the CL7-era framework, with limited exceptions on large sites as later Local Plan wording develops. Always read the current adopted Local Plan basement policy and Basements SPD for the application date of your scheme.

Construction impact, structural design, hydrology and neighbour amenity are central. Party wall engagement is almost always required on mid-terrace basements.

3. Design quality bar

Extensions are assessed for design quality, heritage impact and living conditions of neighbours. Stucco terrace pairs, mews courts and garden squares create composition rules that catalogue rear boxes often fail.

4. Evidence-heavy submission

Householder or full applications need complete drawings; basements need additional technical reports as set out in policy/SPD. Pre-application advice is often worthwhile for basements and contested rear works.

Rear extensions and lightwells

Depth, height and lightwell design are judged against neighbour amenity and conservation character. Lightwells that read as dominant frontage features can be contentious even when rear works are the client’s focus.

Basements (RBKC)

Treat basements as a specialist consent path: policy limits on extent/depth, Basements SPD construction-impact guidance, structural and geotechnical evidence, and construction management. Double basements and large garden undercrofts face a high bar and are often unacceptable outside defined exceptions.

Lofts and roofscape

Roof alterations on formal elevations are sensitive. Rear dormers may be more acceptable than street-facing change, but every roof form is assessed against the host and terrace rhythm.

Policy, SPD and construction reality

RBKC applications often fail when the design ignores published basement limits, underplays construction impact, or proposes materials and massing that harm conservation character. Pretty interiors do not cure a non-compliant envelope.

What a strong RBKC package looks like

Accurate survey-based existing drawings; proposed plans/elevations/sections that match statements; for basements, coordinated technical evidence and construction methodology consistent with the Basements SPD expectations. Freeholder packs on mansion blocks should reuse the same measured model.