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Free 2026 London Planning ReportMansard Loft Conversion Drawings in Putney SW15

Open-plan kitchen extension interior in a Putney SW15 Victorian house near the Thames, Wandsworth
Putney · SW15 · Wandsworth

Mansard Loft Conversion Drawings in Putney SW15

Fixed-fee, MCIAT-chartered mansard loft conversion drawings for Putney (SW15) homeowners — London Borough of Wandsworth validation and local constraints handled from the start.

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Putney (SW15) is unusually heavily conservation-controlled for an outer-inner London neighbourhood: five separate conservation areas — Putney Embankment, West Putney, East Putney, Charlwood Road & Lifford Street, and Oxford Road — cover a large share of the housing. Whether a property sits inside one of those boundaries is the single biggest factor in how an extension or loft is designed and assessed.

Add the Thames on the northern edge, and riverside and Embankment properties also carry flood-zone considerations that have to be addressed in the application. We map a Putney property against the conservation and flood-zone boundaries first, then design the drawings to Wandsworth's residential guidance so the application is validated without a query.

Open-plan kitchen extension interior in a Putney SW15 Victorian house near the Thames, Wandsworth
Isometric illustration of a Putney SW15 home mansard loft conversion drawings design
Proposed floor plan
Putney SW15

Planning in Putney (SW15): what to know before you apply

SW15 has no householder Article 4 direction, but its five conservation areas mean permitted development cannot be assumed across much of Putney, and riverside properties near the Embankment sit within the Thames flood zone — both are checked before we recommend a route.

Typical Putney housing stock

Victorian and Edwardian terraces on the streets climbing from the river, riverside mansion blocks along the Embankment, and interwar semi-detached houses toward Putney Heath and Roehampton.

Streets we regularly draw for in Putney

Putney High Street · Upper Richmond Road · Lower Richmond Road · Disraeli Road

What SW15 is actually built of

Measured from 341 classified residential buildings in SW15, not from a description of the area.

Putney SW15 housing mix

Residential building form across the SW15 postcode district, from 341 classified buildings.

Attached on more than one side55%
Attached on one side34%
Detached10%
Median building footprint71 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate2.14
Buildings classified341

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 Putney (SW15) 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 Putney property in SW15, showing the existing and proposed arrangement at scale
A sheet from the mansard loft conversion drawings package we submit to London Borough of Wandsworth for Putney (SW15) properties.
FAQ

Mansard Loft Conversion Drawings in Putney SW15 — 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 a side-return extension in Wandsworth?+
On many of Wandsworth's Victorian terraces a single-storey side-return or rear extension can fall within permitted development, so a full application isn't always required. Conservation areas such as Wandsworth Common and Nightingale Lane, and the 'between the commons' streets, can restrict this. We check your street's designation first and can secure a Lawful Development Certificate where the work is permitted development.
What does Wandsworth's basement Article 4 direction mean for me?+
In parts of Wandsworth an Article 4 direction removes permitted development for basement works, and the council requires a Basement Impact Assessment covering structural stability, drainage and groundwater. If you are considering a basement or lower-ground extension we flag whether the direction applies to your address early, and coordinate the structural input so the application is complete when submitted.
How long will Wandsworth take to decide my application?+
Wandsworth determines most householder applications within the statutory eight-week window once the submission is validated. Because the terraced grids around the commons are party-wall-sensitive and design expectations are well established, the commonest delay is a drawing query — so we prepare Wandsworth submissions to the validation checklist to keep them moving.
Can you design an extension for a converted flat near the commons?+
Yes. Much of Battersea and the streets around Clapham and Wandsworth Commons are mansion blocks and converted flats, where ownership, lease and party-wall considerations shape what is deliverable alongside the planning route. We confirm the ownership and structural context before drawing, and coordinate the calculations in-house so party-wall-sensitive schemes are handled cleanly.
How much do Wandsworth planning drawings cost?+
We agree a fixed fee before starting, usually around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Wandsworth approves. The price depends on the scheme — a side-return differs from a mansard loft or a basement — so we quote once we have seen your project rather than charging by the hour.
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