Mansard Roof Extensions · W14 West Kensington
Fixed-fee mansard roof extensions for West Kensington, Barons Court, Olympia, Holland Park fringe in the W14 postcode, drawn by an MCIAT-chartered architectural technologist and submitted to Hammersmith & Fulham Council. W14 spans Hammersmith & Fulham and Kensington & Chelsea; conservation control is strong around Barons Court, and the Earls Court scheme borders the area.
MCIAT chartered drawings for planning, building regs, lofts and extensions — fixed fees 30% below typical London architects. Tell us what you need and we’ll reply the same working day.
A mansard roof extension adds a full storey behind a new sloping front face — a strong option on W14's terraces in West Kensington where a standard dormer is too small. Hammersmith & Fulham Council scrutinises mansards on townscape and precedent, especially within Barons Court, West Kensington, Edwardes Square / Scarsdale fringe; we design to the borough's roof guidance with a Heritage Statement where the setting requires it.
West Kensington's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in West Kensington conservation areas — with heritage statements and planning officer negotiation built in.
Across West Kensington, Barons Court, Olympia, Holland Park fringe in W14, the dominant property is grand victorian terraces and mansion blocks around west kensington and barons court, with artists' studio houses near holland park. That stock shapes what mansard roof extensions looks like here: the right approach for a period terrace differs from a mansion-block flat or a new-build, and Hammersmith & Fulham Council judges each on design quality and neighbour impact. We survey the specific West Kensington property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the W14 streetscape.
Housing stock in W14: Grand Victorian terraces and mansion blocks around West Kensington and Barons Court, with artists' studio houses near Holland Park.
Within the district: West Kensington, Barons Court, Olympia, Holland Park fringe.
Streets we know in W14: the Barons Court streets (Gledstanes Road, Castletown Road), the Gibbs Green area and the Edwardes Square fringe. Each road has its own building line, boundary treatment and precedent that Hammersmith & Fulham Council weighs when assessing a mansard roof extensions scheme.
Conservation areas: Barons Court, West Kensington, Edwardes Square / Scarsdale fringe. Inside these, most external work needs full planning and a Heritage Statement.
Getting around W14: West Kensington and Barons Court on the District and Piccadilly lines, plus Kensington Olympia.
Regeneration: West Kensington falls within or beside the Earls Court / West Kensington regeneration, which shapes local planning policy and design expectations.
Property values: around £550,000 for a flat and £1.2m-£2m for a house — a useful gauge of the build value an extension or loft adds in W14.
Borough character: Suburban-feel residential streets with strong conservation area coverage; well-established mansard precedents on many terraces.
We check against Hammersmith & Fulham Council's mansard design guide and design to match the terrace.
Required for West Kensington's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at Hammersmith & Fulham Council committee.
Mansards invariably trigger Party Wall notices in West Kensington's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with Hammersmith & Fulham Council planning officer, committee representation if called in.
Part L thermal, Part B fire (critical on mansards), Part E acoustic separation.
Single planning or building-regs submission.
Planning + building regs + structural.
Listed, conservation or complex sites.
Yes, but the handsome Victorian terraces around Gledstanes Road and Castletown Road sit in the Barons Court conservation area, so rear and side extensions and roof changes need full planning with a Heritage Statement rather than Permitted Development. We design to match the period detailing and submit to Hammersmith & Fulham.
W14 straddles the boundary — West Kensington and Barons Court largely sit in Hammersmith & Fulham, with the eastern edge toward Holland Park in Kensington & Chelsea. The two councils apply different conservation and basement controls, so we confirm your exact authority before quoting.
The major Earls Court / West Kensington regeneration borders W14, bringing thousands of new homes and improved public realm, supporting values. For a house project the binding controls remain Permitted Development limits and the local conservation area, which we check for your address.
Yes. The mansion blocks around West Kensington and Olympia usually have freeholder controls alongside council planning, and any external change needs full consent. We produce drawings that satisfy both the freeholder and the council, and handle Party Wall matters between flats.
Our fixed fee for mansard roof extensions in West Kensington starts at £1,575 — no hourly billing. With West Kensington property at around £550,000 for a flat and £1.2m-£2m for a house, the professional drawing fee is a small fraction of the value the work adds to W14's grand victorian terraces and mansion blocks around. Hammersmith & Fulham Council charges its own statutory application fee on top (currently £258 for a householder planning application, £578 for a full application). We quote the drawings as one fixed price and the free site survey covers every W14 address.
For a W14 project across West Kensington, Barons Court, Olympia, Holland Park fringe, expect roughly 3–4 weeks from instruction to submission: week 1 the measured survey, weeks 2–3 the drawings and your revisions, then validation and the statutory determination by Hammersmith & Fulham Council (8 weeks for a householder application). We carry the West Kensington application through every officer query to the decision.
West Kensington (W14) sits primarily in Hammersmith and Fulham, so applications are decided by Hammersmith & Fulham Council. Article 4 in force in the borough: Yes. Conservation areas within W14 include Barons Court, West Kensington, Edwardes Square / Scarsdale fringe, where full planning and a Heritage Statement are required. We confirm the planning route for your exact address before quoting.
Almost always. Any structural work behind mansard roof extensions in West Kensington — new openings, steel beams, loft floors, foundations — needs Building Regulations approval covering structure (Part A), fire escape (Part B) and insulation (Part L), submitted to Hammersmith & Fulham Council Building Control or an approved inspector. On W14's typically terraced and semi-detached stock, a Party Wall notice to adjoining neighbours is normally required before the steelwork. We coordinate both as part of the Complete package.
In value terms, yes. With West Kensington (W14) property at around £550,000 for a flat and £1.2m-£2m for a house, a well-designed extension or loft typically returns more than it costs in added floor area and sale value, while our fixed drawing fee from £1,575 keeps the professional cost predictable. The bigger risk is an unapproved or non-compliant scheme — which is why council-ready drawings and a clean Building Control sign-off matter on W14 homes.
From £840.
From £840.
From £1,225.
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From £995.
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Pick a slot that suits you. No obligation and no sales pressure — just straight answers on your planning route, fixed fee and timescale.
Every W14 postcode district we draw in, the stock that dominates it and the authority that validates a mansard roof extension there. W14 fees below are the statutory England rates for 2026, not mansard roof extension estimates.
| Postcode | Area | Dominant stock | What it means for a mansard roof extension |
|---|---|---|---|
| W14 | West Kensington / Barons Court | Victorian and Edwardian villas | W14 straddles a boundary: West Kensington / Barons Court addresses fall to Hammersmith & Fulham Council or RBKC Planning, so confirm which authority validates the mansard roof extension before submitting W14 drawings. |
| W14 | Barons Court | Edwardian mansion blocks, Victorian terraces | Barons Court sits inside W14; mansard roof extension proposals here are determined by Hammersmith & Fulham Council. |
| W14 | Holland Park | Victorian and Edwardian villas | Holland Park sits inside W14; mansard roof extension proposals here are determined by RBKC Planning. |
| SW6 | Fulham / Parsons Green | Victorian terraces, mansion blocks | Adjoining district to W14, also inside Hammersmith and Fulham for mansard roof extension purposes. |
| W6 | Hammersmith / Brackenbury Village | Victorian terraces, mansion blocks | Adjoining district to W14, also inside Hammersmith and Fulham for mansard roof extension purposes. |
| W12 | Shepherd's Bush / White City | Victorian and Edwardian terraces | Adjoining district to W14, also inside Hammersmith and Fulham for mansard roof extension purposes. |
| SW3 | Chelsea / Brompton | Georgian and Victorian terraces, listed buildings | Adjoining district to W14, also inside Kensington and Chelsea for mansard roof extension purposes. |
| SW5 | Earl's Court | Stucco terraces, Edwardian mansion blocks | Adjoining district to W14, also inside Kensington and Chelsea for mansard roof extension purposes. |
| SW7 | South Kensington / Knightsbridge | Stucco terraces, mansion blocks, listed buildings | Adjoining district to W14, also inside Kensington and Chelsea for mansard roof extension purposes. |
| SW10 | West Brompton / World's End | Georgian and Victorian terraces, listed buildings | Adjoining district to W14, also inside Kensington and Chelsea for mansard roof extension purposes. |
Roof pitch, wall build-up and plot depth change every few W14 streets, and each one changes what a mansard roof extension can achieve at that address.
How designation changes a W14 (West Kensington / Barons Court) mansard roof extension: Hammersmith & Fulham Council maintains 45 conservation areas, including Hammersmith Grove, Brackenbury Village, Fulham Palace Road. Inside any of them a W14 (West Kensington / Barons Court) mansard roof extension cannot rely on permitted development, and the route becomes a £258 householder application determined in 8 weeks rather than a £120 prior approval in 6 weeks. Walham Green sets the tone for W14 (West Kensington / Barons Court) casework.
W14 (West Kensington / Barons Court) and Article 4: Article 4 removes PD for HMO conversions; restrictions on ground-floor shop-to-residential in certain streets. A mansard roof extension planned at a W14 address is checked against that direction first; Hammersmith & Fulham Council publishes the W14 (West Kensington / Barons Court) extent, and the W14 line rarely follows the W14 (West Kensington / Barons Court) boundary you would expect.
The building fabric around W14 (West Kensington / Barons Court): Victorian and Edwardian terraces — particularly two-storey bay-fronted terraces south of the river in Fulham and Parsons Green; mansion blocks along main roads. Suburban-feel residential streets with strong conservation area coverage; well-established mansard precedents on many terraces. A mansard roof extension in W14 (West Kensington / Barons Court) is scoped against that stock first. Our W14 (West Kensington / Barons Court) fixed fee starts at £1,575; the £1,750 Complete package runs the W14 (West Kensington / Barons Court) scheme through Hammersmith & Fulham Council planning and building control in one go.
How designation changes a W14 (West Kensington / Barons Court) mansard roof extension: RBKC Planning maintains 38 conservation areas, including Kensington, Chelsea, Notting Hill. Inside any of them a W14 (West Kensington / Barons Court) mansard roof extension cannot rely on permitted development, and the route becomes a £258 householder application determined in 8 weeks rather than a £120 prior approval in 6 weeks. Earls Court sets the tone for W14 (West Kensington / Barons Court) casework.
W14 (West Kensington / Barons Court) and Article 4: Article 4 Directions covering HMOs, office-to-residential, and basement developments — RBKC has some of the strictest basement policies in London. A mansard roof extension planned at a W14 address is checked against that direction first; RBKC Planning publishes the W14 (West Kensington / Barons Court) extent, and the W14 line rarely follows the W14 (West Kensington / Barons Court) boundary you would expect.
W14 (West Kensington / Barons Court) below-ground policy: RBKC's basement policy (post-2015) limits to single-storey under 50% of garden area; double-storey basements effectively prohibited in residential streets. Any mansard roof extension in W14 (West Kensington / Barons Court) that goes below existing foundations triggers two months notice under section 6 of the Party Wall etc. Act 1996, and RBKC Planning will want the W14 ground and groundwater position set out.
The building fabric around W14 (West Kensington / Barons Court): Grand white stucco Regency and Victorian terraces; red-brick Queen Anne mansions in Kensington; Edwardian mansion blocks; almost no post-war housing stock. Internationally wealthy residents; extensive listed building coverage; heritage and streetscape prioritised in every decision. A mansard roof extension in W14 (West Kensington / Barons Court) is scoped against that stock first. Our W14 (West Kensington / Barons Court) fixed fee starts at £1,575; the £1,750 Complete package runs the W14 (West Kensington / Barons Court) scheme through RBKC Planning planning and building control in one go.
Sources for this W14 mansard roof extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
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