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

Bromley loft conversion plans for £589

In Petts Wood no dormer can rely on permitted development, and in Bromley’s other conservation areas Class B is closed too. We find out which rule your roof falls under before we draw.

  • £439 drawings + £150 survey (£589 total)
  • Petts Wood check first
  • Dormer dimensions annotated

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What do loft drawings cost in Bromley?

The total is £589: £439 for the drawings and submission, £150 for our survey, no VAT to add. Bromley Council’s fee goes to the council. If the officer wants a change, we redraw at no charge until the decision.

In the Bromley loft fee

  • A roof survey with the eaves, ridge, party walls and stair position measured
  • Existing and proposed roof plans, which Bromley makes mandatory for any dormer or rooflight
  • Elevations of every side, with the dormer’s width, height and depth written on
  • Sections through the new floor showing ceiling heights
  • Submission to Bromley, or a certificate application where Class B holds
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

Petts Wood: the roof rights are gone

Bromley confirmed an Article 4 direction removing Part 1 Classes B and C from the whole Petts Wood Area of Special Residential Character; it took effect on 19 July 2022 (Bromley Article 4). Class B is the loft right, so a hip-to-gable or rear dormer in Petts Wood is a householder application, not a certificate case. A second direction removes Class C alone in the Chislehurst Road Conservation Area.

Outside those areas Class B can still apply, but never on article 2(3) land such as a conservation area. We check the designation for your address before quoting, because it decides which paper goes in.

What Bromley wants drawn for a loft

Bromley’s checklist makes roof plans mandatory where there are roof alterations, including dormers and rooflights, and elevations of all sides, terraced and semi-detached houses included. Key dimensions must be written on: width, overall height and depth of the dormer, and the distance to site boundaries where relevant (Bromley checklist).

Sections become mandatory if the roof height rises or the floor-to-ceiling heights change, so a loft that lifts the ridge brings one more sheet into the pack. Bromley’s form also has to carry the biodiversity net gain exemption.

Timescale and levy

Householder applications have an 8 weeks target. In the year to June 2026 Bromley decided 1,063 of 1,179 inside it.

Bromley’s CIL is £120.12 per square metre for 2026 permissions (Bromley CIL), but the checklist only asks for the CIL form where new floor space reaches 100 m² or more, which a loft inside the existing roof does not.

Bromley lofts in numbers

1063 of 1179
Bromley 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)
19 Jul 2022
Date the Petts Wood direction removing Classes B and C took effect. Bromley Council: Article 4 directions on Part 1 Classes B and C
Whole area
Bromley’s Petts Wood direction removes Classes B and C across the entire Area of Special Residential Character. Bromley Council: Article 4 directions on Part 1 Classes B and C
Roof plan
Mandatory in Bromley for any roof alteration, including dormers and rooflights. Validation checklist: householder planning application (Bromley 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)
£120.12 per m²
Bromley’s residential CIL rate for permissions granted in 2026. Calculate the costs of CIL: annual rate summary (Bromley Council)
£72.73 per m²
The Mayor of London’s CIL in Bromley (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)

Bromley loft questions

Can I build a rear dormer in Petts Wood?

Only with planning permission. The Article 4 direction removes the permitted development right for roof additions across the whole Petts Wood area.

Does my Bromley loft need a roof plan?

Yes, Bromley makes one mandatory for any roof alteration, whether a dormer or a rooflight.

Do I need a section drawing?

If the roof height is raised or the floor-to-ceiling heights change, Bromley asks for sections. We draw one through the stair in any case.

Will a loft in Bromley pay CIL?

The checklist asks for the CIL form from 100 m² of new floor space, so a loft inside the existing roof is unlikely to be asked for it.

Check your Bromley roof

Send the address and a photo of the roof. We tell you whether Class B is open or closed and quote a fixed fee.

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