Lambeth's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Lambeth conservation areas — with heritage statements and planning officer negotiation built in.
Lambeth's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Lambeth conservation areas — with heritage statements and planning officer negotiation built in.
Housing stock in Lambeth: Victorian terraces in Clapham, Brixton, Herne Hill; Edwardian villas; 1930s and post-war estates in parts of Streatham; Georgian in Kennington.
Character: Mix of dense Victorian residential and post-war estate; strong conservation area coverage; generally design-led planning decisions.
Article 4: Borough-wide Article 4 for HMO conversions; plus office-to-residential restrictions.
We check against Lambeth Council's mansard design guide and design to match the terrace.
Required for Lambeth's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at Lambeth Council committee.
Mansards invariably trigger Party Wall notices in Lambeth's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with Lambeth Council 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 Lambeth homeowners ask every week about mansard roof extensions.
Start a free quote →Very often yes in Lambeth. Rear mansards are routinely approved by Lambeth Council where the design matches the terrace — including within conservation areas like Clapham Common. 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 Lambeth 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. Lambeth Council's design guide (where published) takes precedence on detail.
Often yes, but Lambeth Council favours applications supported by wider street precedents. Where mansards already exist nearby in Lambeth, approval is far more likely. We review street precedents at the feasibility stage.
Our architectural fees for a Lambeth mansard start at £1,575 (planning + building regs + structural + heritage statement). Typical Lambeth 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 Lambeth's victorian terraces in Clapham, Brixton, Herne Hill terraced context.
We cover all Lambeth postcodes — {postcodes} — and have submitted mansard applications across the borough. Our heritage statement and design-and-access statement are included in every mansard package.
Lambeth's victorian terraces in Clapham, Brixton, Herne Hill 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 Lambeth 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 Lambeth Council 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 Lambeth 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 Lambeth roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning rou...
From £1,225. The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with ...
From £995. Turn your unused Lambeth garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, full ...
From £1,950. Full architectural technology service for basement digs and cellar conversions in Lambeth — structural underpinning desi...
From £350. Chartered structural engineer calculations for every residential intervention in Lambeth — steel beams, lintels, pad fou...
From £540. Fixed-fee measured surveys across Lambeth from £540 — floor plans, elevations and sections to ±3mm accuracy. Leica Disto...
From £450. End-to-end Party Wall Act 1996 service for Lambeth — Section 1, 3 and 6 notices, schedule of condition surveys, party wa...
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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Free quote in 60 seconds. Fixed fee from £1,575. MCIAT chartered.
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