Cover Note: Why the Insurer Should Meet the Array Before the Scaffolding Comes Down

There is a moment in every renewable retrofit when the scaffolding comes down, the commissioning sheet is signed, and everyone involved exhales. It is also, awkwardly, the moment when many households discover that the most consequential document in the whole project is not the MCS certificate but the insurance schedule sitting unopened on the kitchen table.

For 2026, with heat pumps, home batteries and rooftop PV now entirely ordinary features of the UK housing stock, the underwriting questions have caught up. Insurers are not hostile to renewables; in most cases they are simply uninformed. The remedy is not a better policy — it is a better sequence. Insurance belongs in commissioning, not in the tidy-up afterwards.

What a standard policy quietly assumes

A typical UK home policy is written around a house that does not generate its own electricity, store combustible energy in a wall cabinet, or run a refrigerant circuit in the side return. Nothing in the wording necessarily excludes those things, but the assumptions underneath it change the risk picture: fire load, escape routes, roof loading, water escape, and the cost of reinstating something that is not a kitchen or a bathroom.

The legal backdrop matters here. Under the Insurance Act 2015, a policyholder has a duty of fair presentation — to disclose everything a prudent underwriter would want to know, in a way that is reasonably clear and accessible. For a domestic policyholder the remedies are proportionate rather than all-or-nothing, but proportionality still bites at claim time. A battery installed without notification is precisely the sort of fact that invites a difficult conversation in the worst week of a household's year.

Three systems, three different questions

Rooftop PV

Panels and their mounting are usually treated as part of the buildings, not contents, though the distinction is worth confirming in writing rather than assuming. The practical underwriting concerns are storm and wind uplift, the age and condition of the roof beneath the array, and whether the array is fixed to a roof that a surveyor would already have flagged as near the end of its life. Where an array has been added to a flat roof with ballasted mounting, the question of whether the system constitutes a permanent fixture affects both the policy and any future sale.

Home batteries

This is where insurer interest is sharpest. A lithium-ion cabinet in a garage, utility room or hallway introduces a fire risk that most legacy wordings never contemplated. Expect questions about chemistry, capacity, siting, separation from escape routes and habitable rooms, and whether the installation followed PAS 63100. Serial numbers, commissioning dates and the installer's accreditation all belong in the file. Battery warranties are typically transferable — but only if the paperwork survives, which is an argument for keeping it with the deeds rather than in a drawer.

Heat pumps

Air-source units raise fewer eyebrows than batteries, but the questions are real: refrigerant type and charge, siting and noise under MCS 020, whether the installation complied with MIS 3005, and whether any listed-building or conservation-area consent was needed. Ground-source systems with boreholes or trenches can affect subsidence assumptions, which matters on clay soils.

The documents that decide a claim

At claim time, an insurer's loss adjuster will ask for a small, predictable set of papers. Having them assembled in advance is the difference between a straightforward settlement and a slow, adversarial process.

• The MCS certificate (or equivalent) for the installation
• The commissioning sheet, with dates, signatures and test results
• Electrical certification under BS 7671, plus Part P notification where applicable
• The DNO notification or consent — G98, G99 or G100 as appropriate
• The EPC and any updated floor plan or roof plan
• Serial numbers for inverter, battery and heat pump
• The installer's public liability and workmanship warranty details
• Photographs of the installation at practical completion

Much of this is already produced during a competent installation. The discipline is to send a copy to the insurer at the same time as it goes into the household file, and to ask for written confirmation that the policy has been noted.

Landlords and let properties

The complications multiply where the property is tenanted. A landlord's policy, a tenant's contents policy and any mortgage lender's requirements must all be reconciled. Tenants should be told, in writing, how the systems operate and what they must not do — the classic examples being painting over an inverter, boxing in a battery, or stacking a garage around a heat pump. Where the property is leasehold, the freeholder's building policy may already cover the array, and duplicating cover is a waste of premium rather than a virtue.

A commissioning-week checklist

Before the scaffolding comes down, a household should be able to answer yes to all of the following.

1. The insurer has been told, in writing, what is being installed, where, and by whom.
2. The rebuild sum insured has been reviewed to reflect the added plant and any internal alterations.
3. The policy has been confirmed to cover the systems against fire, storm and accidental damage, with exclusions understood.
4. Any battery has been sited in line with PAS 63100 and the insurer has confirmed the location is acceptable.
5. The commissioning file has been duplicated — one copy for the house, one for the insurer.
6. The warranty terms and their transferability have been checked.
7. For let property, both landlord and tenant have been informed and the mortgage lender notified if required.

On premiums, honestly

Some households will see an increase; many will not. A notified, professionally installed battery is a different proposition from an undeclared one, and several insurers now price the former competitively because the documentation reduces uncertainty. The point is not that renewables are expensive to insure — it is that the premium is only meaningful once the risk is described accurately.

Treat the insurance conversation as the last item on the commissioning agenda, not the first item on a to-do list for some later month. The array will outlast the scaffolding, the installer's van and probably the policy it was first insured under. The paperwork should be able to keep up.