Harrow's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Harrow conservation areas — with heritage statements and planning officer negotiation built in.
Harrow's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Harrow conservation areas — with heritage statements and planning officer negotiation built in.
Housing stock in Harrow: 1930s semi-detached dominates; Edwardian villas in Harrow on the Hill and Pinner; Metropolitan Green Belt in Stanmore and Harrow Weald; post-war flats around Harrow Central.
Character: Outer north-west London suburban; Harrow on the Hill has exceptionally strict heritage controls; rest of borough permissive.
We check against Harrow Council's mansard design guide and design to match the terrace.
Required for Harrow's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at Harrow Council committee.
Mansards invariably trigger Party Wall notices in Harrow's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with Harrow 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 Harrow homeowners ask every week about mansard roof extensions.
Start a free quote →Mansards in Harrow are less common historically — Harrow Council considers each application on its merits. Rear mansards on suitable terraced or semi-detached properties, matching the roofscape, have a reasonable approval rate with the right design and supporting heritage commentary where relevant.
A 70° front slope is typical for Harrow 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. Harrow Council's design guide (where published) takes precedence on detail.
Often yes, but Harrow Council favours applications supported by wider street precedents. Where mansards already exist nearby in Harrow, approval is far more likely. We review street precedents at the feasibility stage.
Our architectural fees for a Harrow mansard start at £1,575 (planning + building regs + structural + heritage statement). Typical Harrow 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 Harrow's 1930s semi-detached dominates 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 Harrow 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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