Notting Hill · W11 · Royal Borough of Kensington & Chelsea

Basement Extensions in Notting Hill, W11

Single-storey basement extensions to Notting Hill houses — designed within RBKC’s strict basement policy and the area’s sensitive garden-square setting, with the BIA, underpinning and waterproofing in-house.

Speak to the studio directly: 020 8054 8756

One Studio. One Contract. One Team.
Architects, Engineers, Surveyors & Builders under one roof
Planning & conservationManaged
Structural engineeringIn-house
Party wall mattersHandled
Listed & periodSpecialist
Fully insured£10M
SW London consultations2 Eaton Gate, SW1

More floor area, one storey below ground

A basement extension adds a full new floor without changing the look of the house from the street — one of the few ways to gain serious space in Notting Hill’s protected, tightly-packed streetscape. Done properly it gives a light, dry, fully tanked room for a kitchen, media room, gym or guest suite.

The Royal Borough has one of the strictest basement policies in London, sharpened in this very part of the borough. New basements are generally limited to a single storey, must not extend under more than half of the garden, need at least a metre of soil above any part beneath a garden, and require a Basement Impact Assessment plus a Construction Traffic Management Plan — with communal gardens, mature trees and close neighbours adding further sensitivity.

We design within that policy from the outset, because a non-compliant scheme is simply refused. Engineering, underpinning, waterproofing and the planning case all sit in one design-and-build contract with a single point of responsibility, and honest budgets in pounds sterling.

What shapes a Notting Hill basement extension

In Notting Hill, the basement policy and the garden-square setting set what is buildable.

01

Single storey only

RBKC policy generally limits a new basement to one storey under the house and part of the garden.

02

Basement Impact Assessment

A BIA covering structure, ground movement and groundwater is required; we commission and coordinate it.

03

Gardens & soil limits

No more than half the garden, with a metre of soil above — and communal gardens add sensitivity.

04

Construction control

A Construction Traffic Management Plan and method statements govern the work on a tight site.

What a Notting Hill basement extension includes

From feasibility against RBKC policy to a dry, finished basement — all in-house.

Policy feasibility

Testing the site against RBKC basement policy before any design work begins.

BIA & reports

Commissioning the Basement Impact Assessment, structural method and CTMP.

Planning & heritage

Drawings and a planning case for a compliant single-storey basement.

Underpinning

Sequential, engineer-designed underpinning to form the new depth safely.

Structure & party wall

Retaining structure, propping and party wall awards with neighbours.

Waterproofing

Type C cavity-drain or tanked systems with pumps and a maintainable design.

Light & ventilation

Lightwells, sun-pipes and mechanical ventilation to make the room usable.

Fit-out & handover

Kitchen, gym, media or guest-suite fit-out, snagging and handover.

Streets & estates across W11

We design and build single-storey basements within RBKC policy across Notting Hill’s terraces and villas in W11.

Portobello RoadLadbroke GroveElgin CrescentStanley CrescentLansdowne RoadClarendon RoadPembridge VillasKensington Park RoadWestbourne GroveLadbroke Square

Notting Hill sits within the Royal Borough of Kensington & Chelsea — see our Notting Hill area page and South West London refurbishment overview.

Questions clients ask before they start

Can I build a basement in Notting Hill?

Usually a single storey, where the site and RBKC’s basement policy allow. We test feasibility against the policy before designing, because a non-compliant scheme will be refused.

What is a Basement Impact Assessment?

A required report covering structural stability, ground movement and groundwater. RBKC needs it to grant consent, and we commission and coordinate it for you.

Can I have a two-storey basement?

Very rarely — RBKC policy generally limits new basements to a single storey. We are honest about what the policy allows on your site before you spend money.

Do communal gardens affect my basement?

They can — gardens, trees and close neighbours make the setting sensitive, and the scheme is judged on its effect on them. We design accordingly and manage the party wall.

How much does a basement cost in Notting Hill?

Basements are the most engineering-intensive works we do. We give an honest budget band in pounds sterling (GBP) after a feasibility review.

More in Notting Hill, W11

Start your Notting Hill basement extension

Book a no-obligation consultation at 2 Eaton Gate in SW1, at our Hampstead studio, or at your property. We will give you an honest read on approvals, programme and budget band — in pounds sterling — before you commit.

Call the studio020 8054 8756
SW London consultations2 Eaton Gate, London SW1W 9BJ

Book a Refurbishment Consultation

Site visit · approvals read · outline budget band (GBP) · programme indication. No obligation.

Send Project Details