Do I need planning permission to change my roof tiles?

Not usually, as long as the new materials don't project beyond the existing roof plane. In conservation areas, you should match the existing materials.

Can I add rooflights without planning permission?

Generally yes, under Class C, as long as they don't project more than 150mm beyond the roof plane.

How much does a roof alteration cost?

Roof alteration costs in London typically range between £5,000 and £15,000, with rooflights at the cheaper end and a full re-roof with new materials at the higher end.

Do I need Building Regulations for a roof alteration?

Depending on the work, you may need Building Regulations approval for structural changes, insulation, or fire safety requirements.

Project guideGPDO Class C

Roof alteration in Barnet: Planning Permission Guide

What you need to know about roof alterations in Barnet — re-roofing, rooflights, and changing materials.

82%

approved in Barnet

£548

application fee

8 wks

typical decision

≤0.15m

rooflight proud

Based on 11 decided applications in Barnet over 36 months (9 granted, 2 refused). Limited data — treat as indicative.

Barnet has over 15 conservation areas including Hampstead Garden Suburb — a unique 1907 planned community with its own Trust exercising very strict design controls alongside council powers. Other notable conservation areas include Totteridge Village, Mill Hill, and Monken Hadley. The northern fringe borders substantial Green Belt around Totteridge and Arkley. Article 4 Directions cover parts of Hampstead Garden Suburb and other heritage streets.

Council planning portal Pre-application advice

Local data PD rules Costs Professionals Constraints FAQs

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5 nearest comparables & refusal reasons for your address.

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Recent roof alteration decisions in Barnet

The 5 most recent decided applications. Addresses redacted to postcode area.

Granted

Retention of existing building with associated proposed roof alterations including lowering the eaves height adjacent to the boundary wit…

EN42026-06-15

Granted

This notification seeks prior approval for the installation of a roof-mounted solar photovoltaic (PV) array system with a total capacity …

N142026-05-08

Refused

Erection of a granny annexe to rear garden with solar panels and rooflights following demolition of the existing garage. Enclosure of the…

N122026-04-17

Granted

Variation of condition 1 (Approved plans) 6 (Noise Impacts ) 7 (Boiler specification) of planning permission 25/4337/HSE dated 22/12/2025…

NW112026-04-14

Unlawful

Installation of 13no. solar panels to the roof

HA82026-03-11

These are borough-wide. See the 5 nearest to your address.

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Permitted Development Rules

Class CPart 1

Any other alteration to the roof of a dwellinghouse

GPDO 2015, Schedule 2, Part 1, Class C

Roof alterations (other than dormers and loft conversions) are covered by Part 1, Class C of the GPDO. The key rule is that the alteration must not project beyond the existing roof plane.

Key dimension limits

Must not project beyond existing roof planeMaterials must match existing

These are the maximum GPDO limits for a detached house with no constraints. Your actual limits depend on your property type, location, and any planning restrictions.

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Typical Costs in London

Roof alteration costs vary depending on the scope — adding rooflights is much cheaper than a full roof replacement.

Roof alterationLondon

Cost per m²

£800–£2,000

construction rate

Typical total

£5,000–£15,000

Typically includes

MaterialsLabourScaffolding

Typically excludes

Planning application feeBuilding regs fee

Covers re-roofing, changing roof materials, adding rooflights. Full roof replacement is at the higher end.

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Which Professionals Do You Need?

Most roof alterations don't need an architect, but a roofing contractor or draughtsperson can prepare any required drawings.

A draughtsperson or architectural technician can prepare any drawings needed. A full architect may not be necessary.

Architect / designerOptional

Roof alterations may need drawings for Building Regulations, but a draughtsperson or roofing contractor can often provide these.

Typical fee: £500–£2,000 (Basic drawings if needed)

Structural engineerNot needed

Party wall surveyorNot needed

Planning consultantNot needed

This guidance is based on a typical semi-detached house with no special constraints. Listed buildings, conservation areas, and attached properties may require additional professional input.

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Conservation Areas & Listed Buildings

In conservation areas, roof alterations that change the appearance of the roof may be more tightly controlled. Materials should match the existing roof.

Conservation areas

Properties in conservation areas often have reduced permitted development rights. Some project types (like side extensions) lose PD rights entirely. An Article 4 Direction can remove additional PD rights.

Listed buildings

Listed buildings (Grade I, II*, or II) have no permitted development rights at all. Any external alteration requires Listed Building Consent in addition to any planning permission. An architect experienced in heritage work is essential.

Check if your property is in a conservation area or has other planning constraints.

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Frequently Asked Questions

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Related guides

Loft conversion

GPDO Class B

Dormer

GPDO Class B

Solar panels

All guides