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Free 2026 London Planning ReportMansard Loft Conversion Drawings in Greenwich

Aerial view of London rooftops and gardens across a borough like Greenwich, from historic terraces to suburban homes
Greenwich · London

Mansard Loft Conversion Drawings in Greenwich

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

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Greenwich stretches from the Georgian streets of West Greenwich and the Georgian-fringed heath at Blackheath — set against the Maritime Greenwich World Heritage Site — out to the Edwardian villas of Westcombe Park and the interwar and post-war suburbs of Eltham and Kidbrooke. The northern, historic core carries strong conservation and protected-view control, while the outer suburbs and newer riverside development along the Thames offer more generous plots for extensions and lofts. The right route depends heavily on where in the borough you are.

The character shifts street by street. Conservation areas at West Greenwich, Ashburnham Triangle, Blackheath, Westcombe Park, Eltham Park and Woolwich each carry design control over materials, rooflines and front elevations, and the sloping sites around Blackheath and the Greenwich hills shape what an extension can be. Protected views toward the Royal Observatory and across the river, together with Article 4 directions on HMO conversions in parts of the borough, mean the constraints on a heritage-led scheme in the historic core differ sharply from a straightforward suburban addition toward Eltham or Charlton.

We prepare Greenwich planning drawings tuned to the specific area — heritage-led applications around West Greenwich and Blackheath, and simpler extension and loft schemes toward Eltham and Kidbrooke — confirming the World Heritage Site setting and conservation designations for your address first. It is the same council-accepted drawing set an architect would prepare, usually at around 30% less, with a fixed fee agreed up front, a roughly seven-day drawing turnaround and free redraws until the Royal Borough of Greenwich approves. Most householder applications are decided within the statutory eight-week period once validated, so we draw to the council's validation checklist from the start.

Aerial view of London rooftops and gardens across a borough like Greenwich, from historic terraces to suburban homes
Isometric illustration of a Greenwich home extension design
Proposed floor plan
Greenwich

Planning in Greenwich: what to know before you apply

A distinctive Greenwich consideration is the Maritime Greenwich World Heritage Site and its buffer zone, where the council protects townscape and long views toward the Royal Observatory — proposals nearby are assessed against that setting. Conservation-area control in West Greenwich, Blackheath and Westcombe Park, and Article 4 directions on HMO conversions in parts of the borough, also apply. We confirm what affects your address before drawing.

Typical Greenwich housing stock

Georgian and early-Victorian terraces around West Greenwich and Blackheath, Edwardian villas in Westcombe Park, interwar and post-war housing toward Eltham and Kidbrooke, and newer riverside development along the Thames.

Areas we regularly draw for in Greenwich

Greenwich · Blackheath · Westcombe Park · Charlton · Woolwich · Eltham · Kidbrooke

What the numbers say about Greenwich planning decisions

These are Royal Borough of Greenwich’s own reported figures, published by government rather than estimated by us. They are what we design against — a borough that refuses one householder application in five needs a different drawing package from one that refuses one in twenty.

Permitted development in Greenwich

Larger householder extensions put to Royal Borough of Greenwich under the prior-approval route, and lawful-development certificates decided, over eight quarters.

Prior approval not requiredWent ahead without a full application0
Prior approval granted154
Prior approval refused126
Granted where a decision was neededFrom 280 determinations55%
Building upwards, prior approval refused0
Certificates of lawful development decided839

Source: Ministry of Housing, Communities and Local Government (PS1 district planning application statistics). Open Government Licence v3.0 Extracted 2026-08-16.

What removes permitted development in Greenwich

Live entries on the national planning registers for Royal Borough of Greenwich. Article 4 directions withdraw permitted development rights, so a project inside one needs a full application rather than prior approval. Revoked and expired entries are excluded.

Conservation areasPermitted development is already narrower inside one14

Source: MHCLG Planning Data Platform. Open Government Licence v3.0 Extracted 2026-08-16.

Mansard Loft Conversion Drawings for Greenwich 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 prepared for a Greenwich property, drawn to Royal Borough of Greenwich validation standards
A sheet from the mansard loft conversion drawings package we submit to Royal Borough of Greenwich.
FAQ

Mansard Loft Conversion Drawings in Greenwich — 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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