Hackney's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Hackney conservation areas — with heritage statements and planning officer negotiation built in.
In Hackney — Victorian terraces dominate; large post-war estates around Hackney Wick; Georgian fragments in De Beauvoir and Stoke Newington; new-build around the Olympic Park for the most part — a mansard roof extensions package is the full measured-survey-to-submission drawing set London Borough of Hackney needs in order to determine an application: existing and proposed plans, elevations and sections at 1:100 and 1:50, a location and site plan, and the supporting statements the case officer asks for.
Prepared and reviewed by the chartered technologist team at Architectural Drawings London — MCIAT chartered, £2m PI insured.Last reviewed 2026-08-03.


Hackney's most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards that get approved in Hackney conservation areas — with heritage statements and planning officer negotiation built in.
Housing stock in Hackney: Victorian terraces dominate; large post-war estates around Hackney Wick; Georgian fragments in De Beauvoir and Stoke Newington; new-build around the Olympic Park.
Character: Young demographic; high design-quality bar in planning; mansards routinely approved in rear-of-terrace positions within conservation areas following the Hackney design guide.
Article 4: Article 4 Direction covers HMO conversions borough-wide and office-to-residential in specific commercial zones.
We check against Hackney Council's mansard design guide and design to match the terrace.
Required for Hackney's conservation areas — demonstrates the mansard respects character and townscape.
Accurate photomontage showing how the mansard sits alongside neighbours — often decisive at Hackney Council committee.
Mansards invariably trigger Party Wall notices in Hackney's dense terraced streets. Structural package includes new ridge, tie beams, floor joists.
Full liaison with Hackney 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.
Move the controls for an indicative figure. It anchors your budget — it is not a quote. Every project is priced after a free survey.
Build costs are separate and quoted by your contractor. See our published fees.
Every Hackney postcode district we draw in, the stock that dominates it and the authority that validates a mansard roof extension there. Hackney fees below are the statutory England rates for 2026, not mansard roof extension estimates.
| Postcode | Area | Dominant stock | What it means for a mansard roof extension |
|---|---|---|---|
| N16 | Stoke Newington / Stamford Hill | Georgian and Victorian terraces | N16 straddles a boundary: Stoke Newington / Stamford Hill addresses fall to Hackney Council or Islington Council, so confirm which authority validates the mansard roof extension before submitting N16 drawings. |
| E5 | Clapton | Victorian terraces, mansion blocks | Clapton sits wholly inside E5, so Hackney Council validates every mansard roof extension submitted from an E5 address. |
| E8 | Hackney Central / Dalston / London Fields | Victorian terraces, post-war flats | E8 covers Hackney Central / Dalston / London Fields only; Hackney Council handles the mansard roof extension, and Hackney Central / Dalston / London Fields case officers apply the E8 conservation-area map. |
| E9 | Homerton / Hackney Wick | Victorian terraces, post-war estates | Homerton / Hackney Wick sits wholly inside E9, so Hackney Council validates every mansard roof extension submitted from an E9 address. |
| EC2A | Shoreditch | Warehouse conversions, modern infill | A mansard roof extension in Shoreditch may land with Hackney Council or City of London Corporation — EC2A crosses the boundary, and the EC2A policies map decides it street by street. |
| N1 | Islington / Hoxton | Georgian and early Victorian terraces | A mansard roof extension in Islington / Hoxton may land with Islington Council or Hackney Council — N1 crosses the boundary, and the N1 policies map decides it street by street. |
| N4 | Finsbury Park / Stroud Green | Victorian terraces, post-war estates | N4 straddles a boundary: Finsbury Park / Stroud Green addresses fall to Haringey Council or Islington Council or Hackney Council, so confirm which authority validates the mansard roof extension before submitting N4 drawings. |
| E2 | Bethnal Green | Warehouse conversions, modern infill | Bethnal Green is split at E2. Either Tower Hamlets Council or Hackney Council can determine a mansard roof extension here, so the E2 address is checked against both policies maps first. |
Roof pitch, wall build-up and plot depth change every few Hackney streets, and each one changes what a mansard roof extension can achieve at that address.
Conservation areas covering Hackney: Hackney Council runs 29, and Stoke Newington, Dalston Lane, Hackney Central are the ones Hackney owners meet most. A mansard roof extension inside a Hackney conservation area loses permitted development, so the Hackney submission is a householder application at £548 decided in 8 weeks — not a £249 prior approval decided in 6 weeks. In De Beauvoir Town a mansard roof extension is judged on the street elevation first.
Hackney and Article 4: Article 4 Direction covers HMO conversions borough-wide and office-to-residential in specific commercial zones. A mansard roof extension planned at a N16 address is checked against that direction first; Hackney Council publishes the Hackney extent, and the N16 line rarely follows the Hackney boundary you would expect.
The building fabric around Hackney: Victorian terraces dominate; large post-war estates around Hackney Wick; Georgian fragments in De Beauvoir and Stoke Newington; new-build around the Olympic Park. Young demographic; high design-quality bar in planning; mansards routinely approved in rear-of-terrace positions within conservation areas following the Hackney design guide. A mansard roof extension in Hackney is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Hackney Council.
Sources for this Hackney mansard roof extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
Direct answers to the questions Hackney homeowners ask every week about mansard roof extensions.
Start a free quote →Very often yes in Hackney. Rear mansards are routinely approved by Hackney Council where the design matches the terrace — including within conservation areas like De Beauvoir Town. 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 Hackney 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. Hackney Council's design guide (where published) takes precedence on detail.
Often yes, but Hackney Council favours applications supported by wider street precedents. Where mansards already exist nearby in Hackney, approval is far more likely. We review street precedents at the feasibility stage.
A Hackney mansard carries more design work than a dormer — heritage statement, street-elevation massing and conservation-led detailing on top of planning, building regulations and structural calculations. Build cost then varies with size, roof geometry and site access. Our design fee is fixed before we start; see our fees.
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 Hackney's victorian terraces dominate terraced context.
We cover all Hackney postcodes — E2, E5, E8, E9, N1, N4, N5, N16 — and have submitted mansard applications across the borough. Our heritage statement and design-and-access statement are included in every mansard package.
Hackney's victorian terraces dominate 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 Hackney 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 Hackney Council accepts them more readily than a simple box extension.

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