Replacing a Flat Roof in a Conservation Area

Section 55 of the Town and Country Planning Act 1990 leaves out any work that does not change the look of the exterior in a way that matters. A flat roof recovered to the same line and finish can sit on that side of the line on a house, since nobody on the street sees a difference.

What does Class C add?

Class C of Part 1, Schedule 2 of the General Permitted Development Order deals with other changes to a house roof, and re-roofing falls inside it. It comes with limits. One is a height rule: the finished roof must not stand proud of the plane of the original by more than 0.15 metres, measured at right angles to the original surface. That matters on a flat roof, because deeper insulation or a taller upstand can lift the finished level.

A second condition covers windows set in a side-facing roof slope. Those must be obscure-glazed, and fixed shut unless the opening part sits more than 1.7 metres above the floor of that room. The Order's own wording is the text to rely on, rather than a summary like this one.

A conservation area counts as Article 2(3) land. The Order puts it in one list with National Parks and designated beauty spots, where some permitted development rights shrink. For roofs, the loss that bites is dormer windows: Class B.1(f) does not allow them there. Class C carries no Article 2(3) exclusion, so a replacement covering stays within Class C just as it would anywhere else.

Does the street's character still matter?

It does, in practice. Swapping slate for another material, or turning a quiet flat roof into a raised parapet, alters the face the building shows the street, and could call for an application. Taunton has a good many designated areas. Somerset Council's table shows the older ones dating from 15 January 1975, revised in 1998 or 2007, with a newer designation covering Haines Hill and Trull Road, dated 14 March 2023. Each has its own appraisal.

The Vivary Park area and Wellington are designated as well. If your road sits near an edge, the council's maps settle which side of the boundary you are on.

An Article 4 direction withdraws permitted development rights across a named area or site, so work that would normally be permitted might need an application. Somerset Council lists directions for the Taunton area, among them Staplegrove Road, confirmed in 1977. What each one removes is written in its own notice, which the planning team can send for your address.

What if the building is listed, or is a flat?

A listed house keeps its Class B and Class C rights but needs listed building consent on top whenever the work touches its special character. The listing statute, section 7 of the 1990 Act, bars any unauthorised alteration of that kind.

Flats and maisonettes fall outside Class C altogether. The Order defines a dwellinghouse so that a whole block of flats, and each single flat inside one, are left out. A flat roof over a flat therefore follows a different route, and the council will say which.

Inside Exmoor National Park the planning authority is the Park authority, not Somerset Council, so an address near the boundary should check which of the two applies.

Planning is one question and Building Regulations are another. Approved Document L lists the replacement of a flat roof's waterproof membrane as renovation, which can bring insulation requirements with it, so the thermal side is checked as well. Somerset Building Control covers Taunton among the former districts and answers on 0300 303 7790, and the Planning Portal sets out the national re-roofing tests.

Who should I ask before work starts?

Contact Somerset Council's planning team. Give the road, the type of building and the new covering, then ask for the answer in writing. Raise Building Regulations with building control separately. Where a straight re-cover changes nothing about how the roof looks, this is often a short conversation, and a conservation area is a good reason to hold it.

Our part is to read the roof, explain how the new covering and edges will look once finished, and write down one total price when the survey is complete. The flat roofing page describes the service, and our answer on flat roof planning permission takes the wider question further. Send us the address and a few details to begin.