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A loft bedroom with a pitched ceiling, two roof windows and glazed doors opening to a balcony

Merton loft conversion plans for £589

Merton’s checklist singles out dormers and rooms with sloping roofs: the section must show finished floor to ceiling heights there. We measure the roof slope on the survey for exactly that.

  • £439 drawings + £150 survey (£589 total)
  • Sloping-roof heights shown
  • John Innes check first

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What do loft drawings cost in Merton?

The total is £589: £439 for drawings and submission and £150 for the survey, with no VAT to add. Merton Council’s fee is paid to the council.

In the Merton loft fee

  • A roof survey with the slope, eaves, ridge and stair measured
  • A cross-section showing floor to ceiling heights in the dormer and sloping-roof rooms
  • Roof plan and elevations at 1:50 or 1:100, with materials marked
  • The 45 degree line drawn where a neighbour’s window is close
  • A fire safety strategy or exception statement, and submission to Merton
From a tape measure in your loft to a submitted set
From a tape measure in your loft to a submitted set: Roof check, then Roof survey, then Route chosen, then Drawings issued, then SubmittedRoof checkType, ridge height,neighboursRoof surveyRafters, purlins,headroomRoute chosenPermitted,certificate orplanningDrawings issuedAbout 7 days aftersurveySubmittedWe deal with theofficer

What Merton asks to see in a loft

Merton’s checklist says cross-sections are to show finished floor to ceiling heights, “particularly in dormers/rooms with sloping roofs”, so the officer can judge floor space and liveability (Merton checklist). Roof plans are at 1:50 or 1:100, and proposed plans and elevations show a 45 degree line from the nearest habitable window to the development.

Householder applications also carry a Planning Fire Safety Strategy or a Reasonable Exception Statement. For a loft the escape route from the new floor is what matters.

Which route: certificate or application

Class B can cover a dormer if the added volume stays within 40 m³ for a terrace or 50 m³ otherwise and the house is not in a conservation area. Merton’s John Innes Merton Park and Wilton Crescent conservation areas carry four Article 4 directions (Merton conservation areas), so a loft there is an application. For example, a rear dormer outside the conservation areas can be tested for a certificate first.

Timescale

Merton decided 303 of 406 householder applications inside 8 weeks in the year to June 2026, so we send a complete pack and answer queries the same day.

Merton lofts in numbers

303 of 406
Merton Council householder applications decided within 8 weeks in the year to June 2026, out of all it decided (prior approvals not counted). MHCLG live table PS2, planning application statistics by district, July 2025 to June 2026 (GOV.UK)
Dormer heights
Merton asks for sections showing floor to ceiling heights, particularly in dormers and rooms with sloping roofs. Local Validation Checklist 2025, updated June 2026 (Merton Council)
1:50 or 1:100
Scales Merton asks for on roof plans and elevations. Local Validation Checklist 2025, updated June 2026 (Merton Council)
45 degrees
Line from the nearest habitable window that Merton wants shown on proposed plans and elevations. Local Validation Checklist 2025, updated June 2026 (Merton Council)
4
Article 4 directions listed for the John Innes and Wilton Crescent conservation areas. Conservation areas (Merton Council)
40 m³ / 50 m³
Permitted roof volume increase: 40 m³ for a terraced house, 50 m³ for other houses. GPDO 2015, Schedule 2, Part 1, Class B: additions to the roof (legislation.gov.uk)
£72.73 per m²
The Mayor of London’s CIL in Merton (band 2) for permissions granted in 2026, owed only when a scheme is liable for CIL in the first place. Mayoral CIL: annual rate summary for 2026, Table 1 (Greater London Authority)

Merton loft questions

Why does Merton want ceiling heights in the dormer?

Its checklist wants sections to show floor to ceiling heights, particularly in dormers and rooms with sloping roofs, to assess floor space and liveability.

Is a loft in John Innes permitted development?

No. It is a conservation area with four Article 4 directions, so it needs an application.

Does a Merton loft need a fire strategy?

Merton’s list asks a householder for one of two papers on fire safety, and the choice depends on the house. We work out which and write it.

How fast is Merton?

It decided 303 of 406 householder cases within 8 weeks in the year to June 2026. We cannot promise a date.

Check your Merton roof

Send the address and a roof photo. We say which route fits and quote a fixed fee.

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