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 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 {location} roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning ...
From £1,225. The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with ...
From £995. Turn your unused {location} garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, fu...
From £1,950. Full architectural technology service for basement digs and cellar conversions in {location} — structural underpinning d...
From £350. Chartered structural engineer calculations for every residential intervention in {location} — steel beams, lintels, pad ...
From £450. End-to-end Party Wall Act 1996 service for {location} — Section 1, 3 and 6 notices, schedule of condition surveys, party...
From £1,225. London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your ...
Free quote in 60 seconds. Fixed fee from £1,575. MCIAT chartered.
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