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Free 2026 London Planning ReportMansard Loft Conversion Drawings in Greenwich SE10

Rear extension behind a Georgian terrace in Greenwich SE10, Royal Borough of Greenwich
Greenwich · SE10 · Greenwich

Mansard Loft Conversion Drawings in Greenwich SE10

Fixed-fee, MCIAT-chartered mansard loft conversion drawings for Greenwich (SE10) homeowners — Royal Borough of Greenwich validation and local constraints handled from the start.

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Greenwich (SE10) is among the most heritage-sensitive places to build in London: most of its period housing sits within one of the Royal Borough's conservation areas — West Greenwich, Greenwich Park, East Greenwich or the Ashburnham Triangle — and three of those carry Article 4 directions that pull nearly all external work into the planning system. Side-return and rear extensions on the Victorian and Georgian terraces are the staple, but they are judged carefully on materials, proportion and detail.

SE10 also sits within, or beside, the Maritime Greenwich World Heritage Site: the inscribed core is the Old Royal Naval College, Queen's House, Royal Observatory and Cutty Sark, with the surrounding streets in the buffer zone. That means townscape and setting weigh heavily on how schemes are assessed. We check exactly which conservation area — and which Article 4 direction — applies to a Greenwich address before advising on a permitted-development or full-application route.

Rear extension behind a Georgian terrace in Greenwich SE10, Royal Borough of Greenwich
Isometric illustration of a Greenwich SE10 home mansard loft conversion drawings design
Proposed floor plan
Greenwich SE10

Planning in Greenwich (SE10): what to know before you apply

Most SE10 houses fall inside the West Greenwich, Greenwich Park, East Greenwich or Ashburnham Triangle conservation areas, and the first three carry Article 4 directions removing permitted-development rights for re-roofing, windows, doors and other external changes. The Maritime Greenwich World Heritage Site and its buffer zone add further townscape scrutiny. We confirm the conservation area and Article 4 status for a specific property before recommending a route and drawing to the Royal Borough's guidance.

Typical Greenwich housing stock

Georgian and early-Victorian terraces around Royal Hill and Crooms Hill, the Victorian terraces of the Ashburnham Triangle, and the streets of West and East Greenwich framing the town centre and Greenwich Park.

Streets we regularly draw for in Greenwich

Royal Hill · Crooms Hill · Ashburnham Grove · Gloucester Circus

What SE10 is actually built of

Measured from 310 classified residential buildings in SE10, not from a description of the area.

Greenwich SE10 housing mix

Residential building form across the SE10 postcode district, from 310 classified buildings.

Attached on more than one side70%
Attached on one side26%
Detached4%
Median building footprint54 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate2.79
Buildings classified310

Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.

Mansard Loft Conversion Drawings for Greenwich (SE10) homes: the package and the process

A mansard is a rebuild of the roof, so the drawings carry more structure than a dormer scheme: the new front and rear slopes with their pitch angles set out, the upstand and party wall junctions, the parapet and gutter detail, and a street-scene elevation showing the new roof against its neighbours.

That street scene usually decides the application. Where a terrace already has approved mansards, the drawing shows the new roof matching their line, pitch and window rhythm; where it would be the first, the case is made on the roof form itself. Either way the argument is drawn, not written.

Mansards belong to terraces and to parapeted stock. The form works because a near-vertical rear wall can rise off the party walls and sit behind a parapet, which is why it is the usual answer in tightly controlled streets and rarely the right answer on a detached house.

What is a mansard loft conversion?

A mansard replaces the rear roof slope — or, less commonly, the front and rear slopes together — with a new near-vertical wall rising from the party walls to a shallow flat roof at the ridge, with small dormer windows set into it. Unlike a dormer, which sits within the existing roof, a mansard changes the shape of the roof itself, which is why it is usually reserved for terraces where the extra headroom and floor area are worth the more involved planning and construction process. Because the new wall runs almost the full width of the house between the party walls, a mansard typically delivers noticeably more usable floor area than a single dormer of any kind, which is why it remains the preferred option on period terraces where every square metre of loft counts.

Does a mansard loft conversion need planning permission in London?

Yes, almost always. Permitted development rights for roof alterations are volume- and shape-limited, and a mansard goes well beyond what those limits allow because it materially alters the roof's profile rather than adding to it. Every mansard we draw is prepared as a full householder planning application, with a design and access statement where the borough requires one, so the council can properly assess the change to the roofline and its impact on neighbours and the street scene.

Why do conservation areas favour mansards?

Many London conservation areas already contain mansard roofs as part of the original streetscape — grand Georgian and Victorian terraces were frequently built with a mansard attic storey behind a parapet, so a matching modern mansard often reads as a restoration of the intended roofline rather than an alteration. Getting that read right depends on matching the existing slate or tile colour, the proportion and spacing of the dormer windows, and the eaves and parapet detailing of the host terrace — details we design in from the first drawing rather than treating as an afterthought.

  • Slate or tile colour and coursing matched to the existing roof and neighbouring properties
  • Dormer window proportions and spacing aligned to the terrace's existing rhythm
  • Eaves, parapet and party wall junctions detailed to sit flush with neighbouring roofs
Typical mansard loft conversion drawing packages
PackageScopePlanning routeFee from
Rear mansard, planning onlyDesign, planning drawings and supporting statementHouseholder planning£1,600
Rear mansard, planning and building regsPlanning drawings plus structural and Part L detailingHouseholder planning£2,200
Front and rear mansardFull roof rebuild on both slopes, with structuralHouseholder planning£2,400
Sheet from a mansard loft conversion drawings package drawn for a Greenwich property in SE10, showing the existing and proposed arrangement at scale
A sheet from the mansard loft conversion drawings package we submit to Royal Borough of Greenwich for Greenwich (SE10) properties.
FAQ

Mansard Loft Conversion Drawings in Greenwich SE10 — FAQs

How much do mansard loft conversion drawings cost in London?+
Planning drawings for a rear mansard typically start around £1,600. A combined planning and building regulations package, or a front-and-rear mansard, usually runs to around £2,200–£2,400 once structural calculations are included.
Can a mansard ever be permitted development?+
Rarely — because it changes the shape of the roof rather than adding within it, a mansard almost always exceeds permitted development tolerances. If you want to avoid a full application, ask us whether a dormer or hip-to-gable conversion would meet your space needs instead.
How long do mansard drawings take?+
A full planning drawing set is typically ready within about 10–14 days of survey, reflecting the extra design and consultation work a full roof rebuild involves. The statutory 8-week householder determination period then runs from validation.
Will a mansard need scaffolding and affect the whole roof?+
Yes — because the existing rear roof slope is removed and rebuilt, a mansard is a larger construction project than a dormer, and we design the sequencing and structural tie-ins with that in mind so your builder can programme the work efficiently.
Do you handle the party wall process as well as the drawings?+
We identify which neighbours require notice under the Party Wall etc. Act 1996 and provide the drawings needed to support the notice, so the party wall and planning processes can run in parallel rather than one waiting on the other.
Do I need planning permission for an extension in Greenwich?+
It depends on the area. The interwar and post-war suburbs toward Eltham and Kidbrooke often retain permitted development rights for rear extensions and lofts, while the historic core around West Greenwich and Blackheath sits within conservation areas where those rights are removed. We check your address against the designations first and can confirm permitted development with a Lawful Development Certificate.
How does the Maritime Greenwich World Heritage Site affect my project?+
Proposals within the World Heritage Site or its buffer zone are assessed against the setting of Maritime Greenwich, where the council protects townscape and long views toward the Royal Observatory. It doesn't rule out an extension, but roof-level and prominent works near the site need careful, context-led design. We confirm whether the setting applies to your address before drawing.
Can I extend a home in Blackheath or Westcombe Park?+
Yes, but these conservation areas carry strong design control over materials, rooflines and front elevations, and sloping sites around Blackheath and the Greenwich hills shape what works. We design context-led drawings that respond to the area's Georgian and Edwardian character and the topography, which is what carries applications to consent here.
How long does the Royal Borough of Greenwich take to decide?+
Greenwich determines most householder applications within the statutory eight-week period once validated; World Heritage Site, conservation and protected-view cases can involve additional consultation. We prepare submissions to the council's validation checklist to avoid the drawing queries that cause most delays.
How much do planning drawings cost in Greenwich?+
We agree a fixed fee before starting, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Greenwich approves. A suburban Eltham extension and a West Greenwich heritage application differ in the evidence required, so we quote once we understand your address and project rather than by the hour.
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