Mansard Roof Extensions in Hammersmith and Fulham

Very often yes in Hammersmith and Fulham. Rear mansards are routinely approved by Hammersmith & Fulham Council where the design matches the terrace — including within conservation areas like Hammersmith Grove. A Heritage Statement and sensitive design following the borough's published guidance are essential for conservation area mansards.

A 70° front slope is typical for Hammersmith and Fulham 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. Hammersmith & Fulham Council's design guide (where published) takes precedence on detail.

Often yes, but Hammersmith & Fulham Council favours applications supported by wider street precedents. Where mansards already exist nearby in Hammersmith and Fulham, approval is far more likely. We review street precedents at the feasibility stage.

Our architectural fees for a Hammersmith and Fulham mansard start at £1,575 (planning + building regs + structural + heritage statement). Typical Hammersmith and Fulham 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 Hammersmith and Fulham's victorian and Edwardian terraces — particularly two-storey bay-fronted terraces south of the river in Fulham and Parsons Green terraced context.

We cover all Hammersmith and Fulham postcodes — {postcodes} — and have submitted mansard applications across the borough. Our heritage statement and design-and-access statement are included in every mansard package.

Hammersmith and Fulham's victorian and Edwardian terraces — particularly two-storey bay-fronted terraces south of the river in Fulham and Parsons Green 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 Hammersmith and Fulham 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 Hammersmith & Fulham Council accepts them more readily than a simple box extension.