Commercial Solar Panels
For Business

Roof and Building Checks Before Your Business Installs

A commercial array adds weight to a roof, fixings through its covering and new cable routes through the building. Before anyone prices panels, four questions about the building itself need answering. Each one is cheaper to settle at survey stage than after equipment has been ordered.

1. Can the roof carry the load?

The Planning Portal says building regulations will normally apply when solar panels go on a non-domestic roof. The existing roof's ability to carry the weight of the panels has to be checked and proven, and some strengthening work may be needed. Building regulations also cover the fire protection and weatherproofing parts of the job. On our commercial projects, independent structural engineers verify the roof's load-bearing capacity before any panels are laid, as set out in the installation process above. If you have the building's original drawings or structural calculations, have them ready for the survey.

Planning is a separate question from building regulations. Our guide to commercial solar planning permission in England covers planning consent for rooftop solar on business buildings.

2. Is the roof fibre cement (asbestos cement)?

If your roof is corrugated fibre cement sheeting, treat it as asbestos-containing until a survey says otherwise. The Health and Safety Executive (HSE) lists fibre cement roof sheets, commonly called asbestos cement, among roofing materials that will not safely support a person's weight and can shatter without warning. Corroded metal sheets and many roof-light sheets are on the same list. HSE's asbestos essentials sheet a14, on removing asbestos cement sheets, says asbestos cement roofs are always fragile and cannot bear weight. Where sheets are overlaid with another material instead of being removed, it says to attach that material to the existing purlins and avoid drilling through the asbestos cement. HSE also reports that in agriculture roughly half the deaths and serious injuries caused by falls involve work on fragile roofs.

That has two practical consequences. First, in non-domestic premises someone has the duty to manage asbestos. According to HSE, that could be the building owner, the landlord, or the person or organisation responsible for maintenance and repair. Where no agreement says who, it falls to whoever controls the premises. HSE's steps for the dutyholder include making a register of asbestos and giving information to anyone who might disturb it, so ask for the asbestos register before the survey rather than after it. Second, a fragile roof changes how the work can be done safely, and on some buildings the roof covering may need attention before solar makes sense. If you run a farm, our agricultural solar page also covers ground-mount options for marginal land.

3. Has your building insurer agreed?

Tell your insurer before you sign an order. RC62, Recommendations for fire safety with PV panel installations, is a joint code of practice from RISCAuthority, MCS and Solar Energy UK. The 2023 edition focuses on fire safety for commercial and industrial rooftop PV and is written as a practical guide for insurers and their clients, covering procurement, ownership, operation and maintenance. Ask your insurer whether they expect the system to follow RC62, and get any conditions in writing so the design can meet them.

4. Do you lease the unit?

If you rent the building, start with the lease. Installing panels on leased premises typically needs the building owner's explicit permission. That permission is often given in a licence to alter, and a licence to alter often requires the tenant to restore the property at the end of the lease. Property solicitors point out that in many leases the roof is part of the premises let to the tenant, who has to keep it in good repair, and that adding panels may mean updating insurance policies. Before the survey, agree in writing who owns the system, who insures and maintains it, and what happens to it when the lease ends. Take legal advice on your own lease, because this section cannot replace it.

Exporting Surplus Power From a Business Site

Can a business get a Smart Export Guarantee tariff?

Yes, within limits. Ofgem's Smart Export Guarantee (SEG) covers solar PV installations with a total installed capacity of up to 5MW. Any export tariff for an installation above 5MW is a commercial contract outside the SEG. Electricity suppliers with at least 150,000 domestic customers must offer at least one SEG-compliant tariff to an eligible generator, and other suppliers can take part voluntarily. You apply to the SEG supplier of your choice, which does not have to be the company that supplies your electricity. Tariffs differ between suppliers and can change, so Ofgem advises shopping around and reviewing your tariff regularly.

To qualify, an installation needs suitable certification, an export meter that can take half-hourly readings, and an export MPAN. For solar PV up to 50kW, certification is typically an MCS certificate or an equivalent accredited scheme. Above 50kW, each SEG supplier decides how it satisfies itself that the installation is suitably certified, so ask your chosen supplier what it needs before commissioning.

Export income should not be what makes the business case work. Every kilowatt-hour you export is one you are not using on site, so if a proposal only pays back on its export assumptions, question the system size.

What export limitation means under G99

The Energy Networks Association's Distributed Generation Connection Guide (March 2026) says generation above 16A per phase connects under EREC G99 rather than G98. That threshold is 3.68kW on a single-phase supply and 11.04kW on a three-phase supply, so every system in the size table above needs a G99 application to the network operator. Northern Powergrid is the network operator serving the North East, Yorkshire and northern Lincolnshire.

Sometimes the local network cannot accept everything a site could export without reinforcement work. Northern Powergrid's code of practice for customer export limitation schemes (IMP/001/015, based on ENA Engineering Recommendation G100) sets out the alternative. A scheme on your side of the supply point measures power flows. It then restricts generation output, increases on-site demand, or both, so that net export from the site never exceeds its Agreed Export Capacity. Northern Powergrid must be satisfied that the scheme limits export in all circumstances. According to the code, export limitation can remove the need to contribute to reinforcement, or to wait for it before connecting, and it lets the generation be sized larger than the export cap. It does not solve every constraint: the code says restrictions caused by fault levels are not managed this way.

An export limit does not stop you generating. It does mean that any generation above what the building uses plus the agreed export figure has to be absorbed by extra on-site demand or is not generated at all. On a site with a steady daytime load that may cost very little. On a building that sits largely idle on sunny weekends, the lost generation can be significant. Where an export limit is likely, ask for the curtailment to be modelled in the proposal. If you run a large logistics building, our warehousing and logistics solar page covers the technical considerations for those roofs.

Frequently asked questions

Updated September 2026.