The short answer
Often not, but the reason differs from a house. A building with flats in it is not a dwellinghouse, so the householder permitted development rights do not reach it. A like-for-like re-roof can still sit outside planning control altogether, because work that does not materially change the outside look is not development. If the covering or the appearance will change, ask Somerset Council first.
Flats are treated differently from houses in the planning rules. The answer turns on whether the finished roof will look the same as the old one.
Why a block of flats is not a house
Householder permitted development rights are the national permissions that let owners carry out certain work without applying. They are written for a dwellinghouse, and the General Permitted Development Order leaves out any building that contains flats, along with each individual flat in it. The roof classes that serve a house, including Class C for roof alterations, therefore do not apply to a block of flats.
So does a flats re-roof need planning permission?
Not automatically, and that is only half the picture. The Town and Country Planning Act 1990 (section 55(2)(a)) takes work out of the definition of development when it leaves the outside look of the building essentially as it was. Planning permission controls development, so such work needs none. A new roof in the same material, colour and profile as the old may therefore sit outside planning control without needing any permitted development right to lean on. "Materially" is a judgement, so it is worth having the council's view in writing before you order anything.
That is why a managing agent's first step is a short email, not a planning application. Our roof replacement page sets out what a full re-roof involves.
When a flats re-roof does need the council
The position shifts once the roof reads differently from the street.
What counts as a change of appearance?
Swapping slate for concrete tile, clay for a flat panel, or one roof form for another changes how the building looks. So can new roof windows, rooflights, solar panels or a raised parapet. Any of these may need a planning application, because the building has no householder rights to fall back on.
Some buildings carry extra layers of protection. In a conservation area the council has more say over appearance. A listed building also needs its own consent from the council whenever the character of the building would change, whatever the planning position. Inside Exmoor National Park, planning goes to Exmoor National Park Authority and not to Somerset Council. An Article 4 direction can withdraw permitted development rights across a set area. If one is listed for your place, put the question of its reach to the planning team.
The easiest route is to send Somerset Council's planning team a brief description of the work with photos of the present roof, and ask them to confirm in writing whether the new one needs an application.
Building Regulations still apply
Planning and Building Regulations are separate systems, and a re-roof can trigger either, both or neither. On the Building Regulations side, the Planning Portal's cut-offs are 25 per cent of the building envelope and 50 per cent of the roof. Stripping an entire block roof goes past the second figure, so your building control body has to confirm what is needed.
What does Part L change on a flats roof?
Under Approved Document L, a new weatherproof membrane on a flat roof is renovation, and its tables set the insulation target for the finished roof. A covering weighing 15 per cent or more above the old one brings in approval plus a structural opinion. Where a re-roof is notifiable, Somerset Building Control charges it as work to a thermal element, and you can reach the team on 0300 303 7790.
Our guide to insulation and Part L on a re-roof sets out the numbers, and the answer on who notifies building control says who files the paperwork.
Who decides, who pays and who manages the work
On a block of flats the roof usually belongs to the structure that the freeholder or management company looks after, and leaseholders contribute through service charges. That makes the first call a practical one: who is the client for the re-roof, and what does the lease say about consulting leaseholders on major works?
What should the managing agent have ready?
Before the survey, gather the lease terms on major works, any listed or conservation designation, the age and material of the existing covering, and any record of past repairs. After the survey, the managing agent has photos of the actual roof and a single written price.
Work at height on a shared building also brings the construction rules into play. The CDM Regulations 2015 ask the client to appoint two dutyholders in writing, one to design and one to run the site, once a second contractor joins the project, and every project gets a construction phase plan. Ask any contractor how they will handle that on your site, who will have access to the roof, and how residents will be told about each phase of the work, including scaffold and any noise.
Flat blocks and the council
Can a leaseholder re-roof their own flat roof?
Only if the lease gives them responsibility for it. In most blocks the roof is a shared part controlled by the freeholder, so the managing agent or management company arranges the work, and council questions go through them. Check the lease, then ask Somerset Council's planning team about any change of material.
What if the council says the new roof needs an application?
Then you apply, with drawings and photos of the proposed covering, before the work begins. We can describe the material, colour and profile you plan to use so the planning team has what it needs. Starting before a required decision puts the whole project at risk, so wait for the answer.
The full picture: Roof replacement and new roofs in Taunton ยท More short answers