Roof alteration in Harrow: Planning Permission Guide
What you need to know about roof alterations in Harrow — re-roofing, rooflights, and changing materials.
Check if your roof alteration qualifiesRoof alterations in Harrow at a glance
approved *
application fee
weeks typical
Based on 15 decided applications in Harrow over 12 months (13 granted, 2 refused). * Limited data — treat as indicative.
Harrow has conservation areas around Harrow-on-the-Hill (a distinctive hilltop village with very strict design controls), Pinner, and Stanmore. Listed buildings are concentrated in Harrow-on-the-Hill and around Harrow School. Green Belt borders the north and west of the borough around Stanmore Common and Harrow Weald. Article 4 Directions cover parts of Harrow-on-the-Hill. The borough has a mix of inter-war semis, garden suburb character, and older village cores.
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Approval probability, 5 nearest comparables, refusal reasons — for your specific address.
Recent roof alteration decisions in Harrow
The 5 most recent decided applications. Addresses redacted to postcode area.
Provision of four shipping containers with solar panels on roof for storage of equipment and provision of a cycle workshop space; water …
Details pursuant to conditions 3 (fireplace), 4 a) rainwater goods b) roof tiles c) baths, toilets, shower and kitchen units d) design (…
Prior approval: Installation of solar panels
Prior approval for the installation of solar panels
Prior approval for the installation of solar panels
These are borough-wide. See the 5 nearest to your address.
Get my report — £9Permitted Development Rules
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
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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Check my limitsTypical Costs in London
Roof alteration costs vary depending on the scope — adding rooflights is much cheaper than a full roof replacement.
Cost per m²
construction rate
Typical total
Typically includes
Typically excludes
Covers re-roofing, changing roof materials, adding rooflights. Full roof replacement is at the higher end.
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Get my estimateWhich 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.
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)
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.
Find out exactly which professionals you need for your roof alteration.
Get personalised guidanceConservation 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.
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 (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.
Check my propertyFrequently Asked Questions
Just want a quick yes/no for your roof alteration?
Run our free 2-minute check to see whether your project likely qualifies as permitted development in Harrow. For personalised approval odds and nearby comparables, get the full report above.
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