Southwark's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Southwark conservation areas — with heritage statements and planning officer negotiation built in.
Southwark's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Southwark conservation areas — with heritage statements and planning officer negotiation built in.
Housing stock in Southwark: Georgian and Regency in Bermondsey and Borough; Victorian terraces in Camberwell and Peckham; Dulwich Estate controlled housing; riverside new-build.
Character: Dulwich Estate private planning scheme affects much of SE21 and SE22; Southwark planning for rest of borough; strong heritage context.
Article 4: Article 4 for HMOs borough-wide; additional Article 4 for office-to-residential in Bermondsey and Elephant & Castle.
We check against Southwark Council's mansard design guide and design to match the terrace.
Required for Southwark's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at Southwark Council committee.
Mansards invariably trigger Party Wall notices in Southwark's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with Southwark 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 Southwark homeowners ask every week about mansard roof extensions.
Start a free quote →Very often yes in Southwark. Rear mansards are routinely approved by Southwark Council where the design matches the terrace — including within conservation areas like Camberwell 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 Southwark 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. Southwark Council's design guide (where published) takes precedence on detail.
Often yes, but Southwark Council favours applications supported by wider street precedents. Where mansards already exist nearby in Southwark, approval is far more likely. We review street precedents at the feasibility stage.
Our architectural fees for a Southwark mansard start at £1,575 (planning + building regs + structural + heritage statement). Typical Southwark 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 Southwark's georgian and Regency in Bermondsey and Borough terraced context.
We cover all Southwark postcodes — {postcodes} — and have submitted mansard applications across the borough. Our heritage statement and design-and-access statement are included in every mansard package.
Southwark's georgian and Regency in Bermondsey and Borough 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 Southwark 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 Southwark 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 Southwark 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 Southwark roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning r...
From £1,225. The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with ...
From £995. Turn your unused Southwark garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, ful...
From £1,950. Full architectural technology service for basement digs and cellar conversions in Southwark — structural underpinning de...
From £350. Chartered structural engineer calculations for every residential intervention in Southwark — steel beams, lintels, pad f...
From £540. Fixed-fee measured surveys across Southwark from £540 — floor plans, elevations and sections to ±3mm accuracy. Leica Dis...
From £450. End-to-end Party Wall Act 1996 service for Southwark — 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 ...
Leave your number and an Architectural technologist will call you back within 30 minutes during working hours.
No obligation. No sales pressure. Just expert advice about mansard roof extensions in Southwark.
Free quote in 60 seconds. Fixed fee from £1,575. MCIAT chartered.
Get my free quote →