Closing up for winter: what almost everyone forgets

The first time I saw a house opened up after a badly closed winter was at Claouey, in February. The owner had shut the water off at the meter — correct — but had not drained. The washing machine hose, still connected and full, had frozen and split along three centimetres. When he reopened the valve in April, forty minutes later the utility room and the hallway floor were fit for a skip.

This is not a story about negligence. It is a story about sequence. Closing a house is not a list of independent actions, it is an order of operations. You shut off and then drain, never the other way round. You set the heating before leaving, not from Paris three weeks later when the forecast turns.

Here is the protocol we apply, in the order we apply it.

I. Water: the one area with no compromise

Nine out of ten winter claims, in the houses we take over, come from water. Not break-ins, not storms: water.

The Bay does not have alpine winters. Temperatures rarely go below −5 °C, and never for long. That is precisely what makes owners careless: severe frost is rare, so nobody guards against it, so the time it does arrive — and it does, every five or six years — the damage is general. February 2012, February 2018, the January 2024 spell: each time, the same trades overwhelmed for six weeks.

The correct sequence:

1. Close the main incoming valve, often in the chamber at the boundary, sometimes in the plant room.
2. Open every outlet, highest to lowest: upstairs taps first, ground floor next, external tap last. Air enters at the top, water leaves at the bottom.
3. Drain the hot water cylinder through the safety group, or isolate its supply and leave it full if it sits in a heated volume. Both schools are defensible; what matters is choosing one.
4. Drain the circuits that do not empty themselves: washing machine, dishwasher, water softener, irrigation system, outdoor shower, pool pump.
5. Pour a little food-grade glycerine or non-toxic antifreeze into every trap — sink, basin, shower, WC. An empty trap lets drain odours back into the house; a trap full of clean water freezes and cracks the ceramic.
6. Close the taps once the flow has stopped. A house left open refills in spring with a fearful bout of water hammer.

II. Electricity: what to cut, what to leave

Throwing the main breaker is a false economy in a well-equipped house. You lose frost protection, alarm monitoring, the cellar fridge, the sump pump and — increasingly — the connection that would tell you something is wrong.

Good practice is to isolate circuit by circuit.

• Cut: water heater, hob, oven, kitchen sockets, EV charger, spa, timed external lighting.
• Leave: frost protection, mechanical ventilation, internet router, sensors, alarm, freezer if you depend on it, occupancy-simulation lighting.

While you are there, check the 30 mA RCD trips: press the test button, it should cut cleanly. Thirty seconds, once a year, and it is the only real protection against electric shock when a tradesman works in your absence.

Photograph the consumer unit once the isolations are done. By May you will have forgotten what you decided in October. We file that photograph in the house record with its date; it has become one of the most consulted documents we hold.

III. Heating: frost protection is not "off"

A point that comes up at every diagnostic: switching the heating off entirely in a stone or timber house on the Bay is a short-term saving paid for in long-term damage.

An unheated house over five months falls to outside temperature, and above all to outside humidity. Winter relative humidity around the Bay runs at about 85%. The dew point moves into the walls. By spring: mould in north-facing corners, wallpaper lifting, a cellar smell in the ground-floor bedrooms, and timber joinery that has swelled and moved.

A sensible setting: 8 to 12 °C in the body of the house. On a heat pump, frost-protection or eco mode. On electric radiators, frost protection plus one notch. On a well-insulated 200 m² villa the extra cost runs to a few hundred euros for the season. Redecorating three rooms after mould is a multiple of that.

IV. Ventilating a closed house

An apparent contradiction: a house you close must keep breathing. This is the most frequent mistake among methodical owners — the ones who do everything properly, and seal everything up.

Mechanical ventilation stays powered, always. If the house has none, leave two air inlets open, ideally on opposite elevations, to create a sweep. Low-level crawl-space vents must not be blocked: they exist precisely to stop the ground floor structure rotting.

In rooms with no mechanical ventilation — dressing rooms, windowless utility rooms, basements — one dehumidifying box per room, emptied at every visit. It is not elegant. It works.

V. Outside: the westerly does more damage than the rain

What owners from inland underestimate is the mechanics of the wind. Not the gusts of named storms, which everyone talks about. The ordinary westerly, blowing three days out of five at 40 or 50 km/h from November to March, working by repetition.

Gutters deserve a special mention. A mature maritime pine sheds needles all year, peaking in late summer and again after the first autumn gales. A blocked gutter means water running down the wall for three months, a saturated wall base, blistering render, and then damp rising. Clearing it costs a few tens of euros. Repairing render runs into thousands.

VI. A house that does not look empty

Burglary of second homes on the Aquitaine coast is seasonal and opportunistic. It targets houses that are obviously unoccupied, spotted from the road: shutters closed for months, a full letterbox, an overgrown garden, no sign of anyone.

What deters, in the order of effectiveness we observe:

• A garden that is visibly maintained in midwinter.
• Shutters that move — not all open, not all closed, and not in the same arrangement week to week.
• External lighting on a sensor rather than a regular timer.
• A car parked in the drive from time to time.
• A monitoring contract, visible by its sticker, but above all real.

An alarm on its own, with no verification and nobody within twenty minutes, protects less than people think. It goes off, it notifies, and then what? The subject deserves its own article: we wrote it as Alarms, monitoring and concierges: who covers what.

VII. The file you leave behind

The last item, the most neglected, and the one that makes the difference when something happens.

Before leaving, assemble somewhere accessible remotely — a shared folder will do — the following: a location plan for the valves and the consumer unit, dated photographs of the main rooms, contact details for the electrician, plumber and roofer who know the house, the insurance policy number and claims line, the gate code, the alarm code, and the name of the person authorised to open the house in your absence.

That last line is the one that is almost always missing. A tradesman cannot work in a house where nobody has authority to let them in. We have seen a leak run for eleven days because the neighbour with the key was himself away and nobody else was authorised.

Should you do all this yourself?

Honestly: you can. Three hours for someone who knows their house, an afternoon for someone learning it. What you cannot do is what follows — the five months during which nobody calls.

A perfect closing in October does not protect against a tile lifted on 12 January. That is the reason we exist: closing up is a task, monitoring is a service. Both are useful; neither replaces the other.

Frequently asked questions

Should the water be shut off at the meter or is closing the taps enough?

At the meter, always, followed by draining the system. Closing internal taps leaves the whole rising main under pressure: a failure on that section empties the public supply into the house until somebody notices.

What temperature should an unoccupied house be kept at in winter?

Between 8 and 12 °C in the body of the house. Below that, condensation and mould in cold corners become a real risk; above it, you are heating for nothing. The factory frost-protection setting on electric radiators is often 7 °C, which is a little low for the Atlantic coast.

How long does closing up a villa for winter take?

About three hours for a 200 m² house whose circuits you know, covering water, electricity, heating, ventilation and the grounds. The first winter always takes longer, while you work out where the valves are and how each item drains.

Can an insurer refuse a claim that occurred while the house was empty?

It can reduce or refuse settlement if the policy contains an unoccupancy clause that was not complied with, or if the required precautions — water shut off, frost protection, periodic visits — were not taken. Read the particular conditions, not just the general ones: that is where the maximum absence periods sit.

Should all the shutters be closed for winter?

No. Closing the west and north sides protects against wind and thermal shock; leaving the south ones workable allows solar gain that dries the house on clear days. A house with every shutter closed since November also announces its emptiness from the road.