When a house needs a new roof, one owner decides. In a block of flats the same roof covers several homes, and the people with a say usually include the freeholder, a managing agent, a residents' company or the leaseholders themselves. The roof may be pitched slate over a Victorian conversion, a long flat roof on a 1960s block, or a mix of the two with a lift housing and chimney stacks in between.
Three things make this different from a house. The planning rules that let a householder alter a roof do not extend to flats. Building Regulations are judged against the whole building, not one flat. And the questions of who instructs, who pays and what the lease allows sit outside the roofing itself and need their own answers.
We cover the roof side here: what consent applies, what building control looks at, how scaffolding is arranged and what shapes the price. What a lease allows, and what a leaseholder must contribute, is a matter of law and the document you signed, and we do not advise on it. Ask a solicitor or the managing agent. For a house, the main roof replacement page is the better start.
Why householder rights stop at the front door of a flat
A householder can make some changes to a roof without applying for planning permission because the General Permitted Development Order gives houses their Part 1 rights. The Order's definition of a dwellinghouse leaves out any building holding one or more flats, and any flat within one. A flat therefore has no Part 1 rights of its own. Anything that would otherwise lean on them, such as a new roof window, a dormer or a change to a chimney, should be put to the planning team before you commit.
Roofing itself is a different matter. Swapping a covering for one of the same kind keeps the building looking as it did. The law counts that as upkeep, not development, so an application is rarely required. The caveats are the familiar ones. A listed block needs consent before works that alter its special character. An Article 4 direction can take rights away within a conservation area, and a few local ones reach the roof itself: Warwick Gardens in Worthing is one, and there is another in each of Old Shoreham and Kingston Buci.
A change of material is a change of look
Slate swapped for concrete tile, or a flat roof raised or re-profiled, alters how the block appears. That is the point at which an application may be needed, and the reason we ask what covers the roof now before recommending anything new.
The legislation lists amendments that have been made to the definition but not yet applied, so read the current wording in the Order itself or ask the planning team on the day you apply.
Who instructs the work, and where the lease comes in
On a block the roof is normally dealt with as a building-wide job. Leases differ in how they describe it, and many treat the roof as part of the structure serving everyone, not part of one flat. Whoever manages the building therefore tends to be the person who instructs the roofer: a freeholder, a managing agent, or a company the residents own. One leaseholder who orders work on the roof above their flat may not be allowed to under the lease, so read it first and speak to the manager.
We can tell you what the roof needs, show you with photographs and set it out in a written quote. We cannot say who is liable for the cost, or what notice your lease or the law requires before work begins. The managing agent, or a solicitor who specialises in leasehold, can. The quote works best as the document that accompanies that conversation.
If you rent rather than own
A tenancy is a different arrangement from a lease. Under section 11 of the Landlord and Tenant Act 1985, a landlord on a lease granted for under seven years must see to repairs on the structure and the outside of the home, gutters and external pipes included, which in plain terms takes in the roof. For a flat, the duty stretches to parts of the building the landlord has an interest in, where the disrepair affects your use of the home. Put the leak to the landlord in writing, and if repairs do not follow, the local councils at Adur & Worthing can come and inspect the home.
When the roof leaks into your flat
You may not be the right person to commission repairs, but you can help the manager by recording dates, photographing the damp and noting where it starts. Our page on repairing or replacing a roof explains how the decision is made once the cause is known.
Building control on a block
For repairs or re-covering, the Planning Portal sets the line at 25 per cent of the building envelope and 50 per cent of the roof, and staying below both normally means no building control application. On a block a full replacement will generally cross the roof limit, so approval comes from the council or from a registered building control approver. The two councils run one building control team from Worthing Town Hall, and the owner has to tell them as the work reaches set stages.
Approval raises thermal questions. Approved Document L requires an upgrade to the entire roof once more than 50 per cent of it is renovated, and the same applies in a major renovation of over 25 per cent of the external envelope. Rebuilding a roof from the structure upwards counts, and so does re-covering a flat deck in a new waterproof skin. Table 4.2 caps the U-value of a new or replacement roof at 0.15 W/(m²·K), which is why insulation belongs in the plan from the start.
Fire and the roof covering
Roof coverings near compartment walls get particular attention in a block. The 2025 amendments to Approved Document B replaced the old national classes with a European one. We check the product against the building's requirements with the building control body, instead of assuming that a covering that suits a house will do.
Heavier coverings
Where the new covering weighs 15 per cent or more above the old, approval is needed and the structure has to be looked at. On an older block that is worth knowing before a heavy tile is specified.
Where work is notifiable, we handle the notification, and the building control team arranges inspections at the stages it sets.
The flat roofs that blocks are built with
Many blocks carry large flat or low-pitched roofs, and these age differently from tiles. MyBuilder gives a typical flat roof life of 15 to 30 years. Coverings vary: Less puts torch-on felt at 10 to 20 years, GRP fibreglass at 25 to 40 and EPDM, the single-sheet rubber membrane, at 30 to 50, while GreenSpec gives EPDM 20 to 30. The sources disagree because workmanship and upkeep change the result so much.
On a block the detail often matters more than the membrane. Water has to reach the outlets, and the design fall is 1:40 to achieve a finished minimum of 1:80, according to IKO citing the 2018 edition of BS 6229 (since revised). Ponding means the fall is not working, and a pool will find the weak spot in a seam or an upstand sooner or later. Outlets clog with leaves, and on a large roof a single blocked outlet can leave water across the whole surface.
Typical flat roof costs
MyBuilder (updated 21/08/2026) gives typical UK ranges of £70 to £100 per m² for felt, £90 to £130 for EPDM and £95 to £150 for GRP, with lead at £150 to £200 or more. Those are guides to the material and fitting, and the survey sets the real figure. Our page on new roof cost covers the pitched equivalents.
Chimneys and stacks
Older blocks keep their stacks, often shared. Taking a chimney off a party wall is notifiable under the GOV.UK guidance: the neighbour must be given notice between two months and a year ahead, and a lack of reply is not a yes. Removing a breast from inside always needs Building Regulations approval. Our guide to chimneys when re-roofing explains the choice between rebuilding and capping.
Scaffolding, access and living under the work
A block almost always needs scaffolding to the full height of the wall, and the cost scales with the building. MyBuilder's guide runs from £850 to £1,200 for the usual two-storey set-up, and Checkatrade quotes about £875 a month for a semi-detached house. A block with more storeys and more frontage will cost more, and the survey fixes the figure.
Section 169 of the Highways Act 1980 requires a written licence for scaffolding that obstructs the highway, and the scaffolders themselves apply for it. The council responsible for highways across Worthing and Adur is West Sussex County Council, which asks for 10 working days' notice and lists a one-month licence at £266 (checked October 2026). Within Brighton and Hove the licence comes from the city council itself, at £118.80 for new scaffold under 12 m. Fees and notice periods change, so confirm with the council, and build the time in before a start date is promised to residents.
Telling residents
The occupiers of every flat are affected, so it helps if the managing agent sends a notice with dates, parking changes and access to bin stores and entrances. Safe walkways past the scaffold and a tidy site matter more on a block than on a house. Rubbish and offcuts leave with us at the end, and the site is handed back clear.
Wildlife and the loft void
Wildlife law covers roosting bats and nests in use, and either can be disturbed by a re-roof. Tell us if you notice them around the roof before work begins, so the plan can allow for it.
Access to the roof itself
Some blocks have a hatch inside a stairwell, others a fixed ladder on an outside wall. We look at how a safe route to the roof can be kept open for the survey and for the later inspection.
Reading a quote for a communal roof
Whatever quote you receive for a block, find out what it covers: the roof area, the covering, the access, and whether the figure has VAT and scaffolding built in. Ours arrives in writing after a survey, with photographs of the roof and one total price. If another contractor's figure leaves VAT or scaffolding out, the two are not comparable, and on a large building the gap can run to thousands of pounds.
For flat roofs, MyBuilder's guide gives a typical range of £2,800 to £7,500, averaging £75 per m², for a single job (updated 21/08/2026). Those figures describe domestic flat roofs and will not map neatly onto a large communal roof, which is priced from its own measurements. What moves the price is the area, the covering, the condition of the deck beneath, the insulation, how many outlets and upstands there are, and the difficulty of reaching the roof.
Storm damage and the building policy
If the roof has failed in a storm, the block's insurer decides the claim. The Financial Ombudsman Service asks if a storm struck on the date in question and if it was what mainly did the damage, and observes that exclusions often cover gradual damage. Keep dated photographs of the roof as it was and as it is. Our first step on a leaking roof is to stop the water coming in, and the cause is traced after that.
What stands behind the work
A flat roof membrane may have its own manufacturer's warranty, whose conditions vary by product, so ask for the document. The managing agent can keep it with the building's records, and a written quote with photographs gives the next committee something to work from. For a single house, the roof replacement overview is the place to compare.
