Barnet's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Barnet conservation areas — with heritage statements and planning officer negotiation built in.
Barnet's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Barnet conservation areas — with heritage statements and planning officer negotiation built in.
Housing stock in Barnet: 1930s semi-detached dominates; Edwardian villas in Muswell Hill, Finchley; Garden Suburb Arts & Crafts in Hampstead Garden Suburb; post-war flats in Colindale.
Character: Suburban outer-London borough; permitted development used heavily; Hampstead Garden Suburb has its own residents' trust with additional design controls.
We check against Barnet Council's mansard design guide and design to match the terrace.
Required for Barnet's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at Barnet Council committee.
Mansards invariably trigger Party Wall notices in Barnet's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with Barnet 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 Barnet homeowners ask every week about mansard roof extensions.
Start a free quote →Mansards in Barnet are less common historically — Barnet 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 Barnet 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. Barnet Council's design guide (where published) takes precedence on detail.
Often yes, but Barnet Council favours applications supported by wider street precedents. Where mansards already exist nearby in Barnet, approval is far more likely. We review street precedents at the feasibility stage.
Our architectural fees for a Barnet mansard start at £1,575 (planning + building regs + structural + heritage statement). Typical Barnet 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 Barnet's 1930s semi-detached dominates terraced context.
We cover all Barnet postcodes — {postcodes} — and have submitted mansard applications across the borough. Our heritage statement and design-and-access statement are included in every mansard package.
Barnet's 1930s semi-detached dominates 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 Barnet 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 Barnet 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 Barnet 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 Barnet roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning rout...
From £1,225. The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with ...
From £995. Turn your unused Barnet garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, full b...
From £1,950. Full architectural technology service for basement digs and cellar conversions in Barnet — structural underpinning desig...
From £350. Chartered structural engineer calculations for every residential intervention in Barnet — steel beams, lintels, pad foun...
From £540. Fixed-fee measured surveys across Barnet from £540 — floor plans, elevations and sections to ±3mm accuracy. Leica Disto ...
From £450. End-to-end Party Wall Act 1996 service for Barnet — Section 1, 3 and 6 notices, schedule of condition surveys, party wal...
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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