Empty units over winter, and the inspection your insurer expects

The number of empty homes in England keeps going up. The government's council tax figures recorded 542,000 dwellings as empty on 10 September 2025, not counting exempt properties, up by 40,000 or 8% on the year before. Around 153,000 of them had been empty long enough to be charged a council tax premium. The next set of figures is due in November.

Most portfolios carry a few of these at any time. A flat between tenancies, a shop unit under a block waiting for a new lease, an upper floor nobody has used since the last occupier left. In summer an empty unit mostly looks after itself. From October onwards it is where the trouble starts, and nobody is there to see it.

Why winter changes the risk

Three things happen to an empty unit once the weather turns.

The water sits. Pipes in an unheated unit can freeze and split, and the leak runs for days before it comes through the ceiling of the occupied flat below. Water that does not freeze stands in the pipework and tanks, which is the condition Legionella bacteria like. HSE's technical guidance, HSG274 Part 2, expects little-used outlets to be flushed at least weekly, and an empty flat is the clearest example of a little-used outlet there is.

The unit is dark. Once the clocks go back on 25 October, a vacant shop front or a flat with no lights on is easier to break into, use or set alight, and post and flyers piling up behind the door say exactly that.

Nobody reports anything. In an occupied unit the resident tells you about the drip, the smell or the broken window. In an empty one the first person to notice is often the neighbour whose ceiling has come down.

What the insurer usually asks for

Most property policies treat an empty building or unit differently once it has been unoccupied for a set period, often 30 or 60 days. Cover can narrow to a short list of events, and the policy usually comes with conditions: water drained down or heating kept on at a set temperature, the unit secured, post removed, and the inside and outside inspected at a stated interval, commonly weekly.

The wording varies, so check your own. The part that catches people out is the evidence. If there is a claim, the insurer will ask when the unit was last inspected, by whom, and what they found. "The caretaker goes in most weeks" is not an answer that holds up.

Where the responsibility sits

An empty flat in an occupied block is still part of the building. The responsible person under the Regulatory Reform (Fire Safety) Order 2005 still has to think about it in the fire risk assessment, particularly for arson and for anything stored there. The water system still sits under the Legionella risk assessment. And under a lease, a leak from a void the landlord controls lands on the landlord.

What to do this month

Make a list of every empty unit you are responsible for, with the date it became empty and whether it is drained down or heated. Check each policy's unoccupancy condition and put the inspection interval it asks for on the calendar, with a named person for each unit. Each visit should cover the same few things: security of doors and windows, any sign of water, the heating or drain down still in place, outlets flushed if the water is live, post cleared, and a couple of photos. Then record it, every time.

When a unit is let again, close the record with the date it was reoccupied so the history is complete.

Where SAMRISK puts it

SAMRISK holds the building and the land it sits on across thirty connected systems, twenty for the building and ten for the land.

Each empty unit's inspection goes on the compliance calendar at the interval the policy asks for, with an owner and a pass or fail history you can hand to an insurer. The policy and its unoccupancy condition sit in insurance, and the stopcocks and isolation valves are recorded in keys and meters. Water hygiene and arson sit in the building's risk assessments. A leak or a broken window raises a maintenance job, a break-in is logged as an incident, and visit photos and contractor reports are filed in documents.

Sources: Ministry of Housing, Communities and Local Government, Council Taxbase 2025 in England, revised January 2026; Health and Safety Executive, HSG274 Part 2, The control of legionella bacteria in hot and cold water systems; Regulatory Reform (Fire Safety) Order 2005.