Updated 26 September 2026. Published by SolarPanelsForFarms.uk (SEO Dons Ltd), an independent publisher. This page explains the rules; it is not a substitute for an asbestos survey or specialist advice on your building.
Asbestos cement (AC) was the default cladding for farm buildings for decades: cheap, durable and easy to fix. It is also the most common reason a farm solar project stalls. The sheets themselves are rarely an immediate hazard while they are intact and left alone; the problem is that fitting solar means people on the roof, fixings through the sheets and, often, a roof that is already at the end of its life. Getting the sequence right — survey, decide on the roof, then design the solar — is what keeps the project safe, legal and financially sensible.
Why you can't treat an asbestos roof like a steel one
HSE's task sheet a14 (removing asbestos cement sheets) puts it in a single line: "AC roofs are always fragile and cannot bear weight." That has two consequences for solar. First, nobody should walk on the sheets: regulation 9 of the Work at Height Regulations 2005 requires employers to prevent work on or near a fragile surface where it is reasonably practicable to do so, and otherwise to provide platforms, coverings, guard rails or similar protection. Second, the sheets cannot carry an array or the point loads of its fixings — and HSE's advice is to avoid drilling through AC at all.
Route 1: overclad the asbestos cement
HSE's a14 sheet asks whether the AC can be overlaid with non-asbestos material instead of being removed, and if so says to attach the new material to the existing purlins, avoiding drilling through the AC. Overcladding gives a new, sound surface that solar rails can fix to in the normal way, without the disturbance and waste of stripping the old roof. The trade-offs:
- ✓ Less disturbance of the asbestos and no asbestos waste from the roof itself.
- ✗ The asbestos stays in the building, so it stays on your asbestos register and must still be managed — including when the building is eventually altered or demolished.
- ✗ The frame now carries the old sheets, the new sheets and the array, so the structural check matters even more.
Route 2: remove the asbestos and re-sheet
Stripping the AC and fitting new sheeting gives the cleanest long-term result: a sound roof, no asbestos left in the building and a clean surface for the array. According to HSE's a14 sheet, removing intact AC sheets on a small scale is normally non-licensed work; if the sheets start to break up and create significant dust, it becomes notifiable non-licensed work (NNLW). The sheet does not apply to large-scale work or mechanical demolition, which needs a full risk assessment and plan of work. A whole barn roof sits closer to that end of the scale, so use a contractor who does this work routinely, with the controls and waste arrangements HSE describes (wetting, suitable protective equipment, sealed asbestos waste bags or a lockable skip).
Route 3: put the solar somewhere else
If the AC building is small, shaded or due for replacement anyway, the simplest answer can be another roof on the holding. A newer steel-clad shed may take the whole array. A ground-mounted array is the other option, but it is not permitted development at farm scale: Class K of Part 14 allows only a single stand-alone unit of up to 9 m², no more than 4 m high and at least 5 m from the boundary, so a field array needs a planning application. See solar panels on farm buildings for how to compare the roofs you have.
Your legal duties before any work starts
Farm buildings are non-domestic premises, so regulation 4 of the Control of Asbestos Regulations 2012 — the duty to manage asbestos in non-domestic premises — applies. The dutyholder is every person with a contractual or tenancy obligation for the maintenance or repair of the premises, or, where there is no such arrangement, whoever has control of them. On a tenanted farm the lease decides whether that is the landlord, the tenant or both, so settle it in writing before commissioning a solar survey. In practice the sequence is:
- 1. Survey. Have the roof sampled and surveyed so everyone is working from facts, not assumptions about "old sheeting".
- 2. Decide the roof strategy. Overclad, re-sheet or move the array — each changes the structural design and the programme.
- 3. Design the solar. Only then should an installer finalise the mounting system, the layout and the price.
- 4. Plan the access. Fragile-roof controls under the Work at Height Regulations for everyone on the roof, for the roof work and the solar work alike.
Planning once the roof is sorted (England)
A re-sheeted or overclad farm building is treated like any other non-domestic roof for solar: Class J of Part 14 of the General Permitted Development Order 2015 allows rooftop panels that stand no more than 0.2 m proud of a pitched roof (1 m above a flat roof) and sit at least 1 m back from the roof edge. There has been no capacity cap since 21 December 2023, but arrays above 50 kW need a prior approval application about design and glare, and listed buildings are excluded. Whether the re-roofing itself needs consent depends on how much it changes the building's appearance — ask the local planning authority early.
Paying for it
We have not found a current grant in England that pays for asbestos removal ahead of solar. England's Improving Farm Productivity grant funded 25% of solar on farm building rooftops, but round 2 is closed, and its solar strand paid towards solar PV equipment such as panels, inverters and batteries. The solar system itself is special rate expenditure for capital allowances (section 104A(1)(g) of the Capital Allowances Act 2001); how the roof work is treated for tax depends on whether it is a repair or an improvement, so take your accountant's view on that part before you sign.