Kensington and Chelsea's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Kensington and Chelsea conservation areas — with heritage statements and planning officer negotiation built in.
Kensington and Chelsea's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Kensington and Chelsea conservation areas — with heritage statements and planning officer negotiation built in.
Housing stock in Kensington and Chelsea: Grand white stucco Regency and Victorian terraces; red-brick Queen Anne mansions in Kensington; Edwardian mansion blocks; almost no post-war housing stock.
Character: Internationally wealthy residents; extensive listed building coverage; heritage and streetscape prioritised in every decision.
Article 4: Article 4 Directions covering HMOs, office-to-residential, and basement developments — RBKC has some of the strictest basement policies in London.
Basement policy: RBKC's basement policy (post-2015) limits to single-storey under 50% of garden area; double-storey basements effectively prohibited in residential streets.
We check against RBKC Planning's mansard design guide and design to match the terrace.
Required for Kensington and Chelsea's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at RBKC Planning committee.
Mansards invariably trigger Party Wall notices in Kensington and Chelsea's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with RBKC Planning planning officer, committee representation if called in.
Part L thermal, Part B fire (critical on mansards), Part E acoustic separation.
Single planning or regs submission.
Planning + building regs + structural.
Listed, conservation, complex sites.
Direct answers to the questions Kensington and Chelsea homeowners ask every week about mansard roof extensions.
Start a free quote →Mansards in Kensington and Chelsea are more heavily scrutinised than in outer boroughs. RBKC Planning prioritises heritage and townscape — approvals require exceptional design quality, clear precedents on the street, and a full Heritage Statement. We've delivered mansard approvals in the borough; each application is bespoke.
A 70° front slope is typical for Kensington and Chelsea mansards — steep enough to maximise floor area while reading as a roof rather than a full additional storey. Front dormers should be small and symmetrical. RBKC Planning's design guide (where published) takes precedence on detail.
Often yes, but RBKC Planning favours applications supported by wider street precedents. Where mansards already exist nearby in Kensington and Chelsea, approval is far more likely. We review street precedents at the feasibility stage.
Our architectural fees for a Kensington and Chelsea mansard start at £1,575 (planning + building regs + structural + heritage statement). Typical Kensington and Chelsea build costs are £90,000–£150,000 depending on size, complexity and access.
Full-height — typically 2.3–2.5m ceiling from the new floor. Unlike a dormer, which gives partial head height, a mansard provides a complete additional storey within Kensington and Chelsea's grand white stucco Regency and Victorian terraces terraced context.
We cover all Kensington and Chelsea postcodes — {postcodes} — and have submitted mansard applications across the borough. Our heritage statement and design-and-access statement are included in every mansard package.
Kensington and Chelsea's grand white stucco Regency and Victorian terraces terraced stock is the natural context for mansard extensions — they were originally designed for Victorian and Edwardian rows. Feasibility depends on street precedent, conservation area status and party wall implications. We assess all three at the free site visit.
A mansard adds a full upper storey — typically 35–45m² of usable floor space. In Kensington and Chelsea this often converts a 3-bed house to 4 or 5 beds. The steep front slope (70°) and flat top read as a roof, not a full floor, which is why RBKC Planning accepts them more readily than a simple box extension.
We cover every London borough with the same fixed-fee approach. If your property sits on a boundary, here are the neighbouring options.
We cover every architectural technology service in Kensington and Chelsea with one chartered team.
From £840. A fixed-fee, end-to-end service — measured survey, scaled drawings, Design & Access Statement where required, Planning P...
From £840. A construction-ready drawing package compliant with every Approved Document — Part A structure, Part B fire, Part L ther...
From £1,225. Every loft type across every Kensington and Chelsea roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or fu...
From £1,225. The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with ...
From £995. Turn your unused Kensington and Chelsea garage into a bedroom, home office or open-plan kitchen-diner. Planning route as...
From £1,950. Full architectural technology service for basement digs and cellar conversions in Kensington and Chelsea — structural un...
From £350. Chartered structural engineer calculations for every residential intervention in Kensington and Chelsea — steel beams, l...
From £540. Fixed-fee measured surveys across Kensington and Chelsea from £540 — floor plans, elevations and sections to ±3mm accura...
From £450. End-to-end Party Wall Act 1996 service for Kensington and Chelsea — Section 1, 3 and 6 notices, schedule of condition su...
From £1,225. London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your ...
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