Water is the first decision
Turning off the main stopcock is the single measure that prevents most damage. A joint that starts weeping in November with the house empty can run for four months, and what you find in March is not a drip, it is a lifted floor.
If you do turn it off, open a tap first to release the pressure in the system. And remember that with the water off, the washing machine and dishwasher hoses should not be left under pressure either.
The traps, which nobody remembers
Every drain has a trap holding a plug of water that stops sewer smell coming up. After three or four months unused, that water evaporates and the house smells stale in a very particular way.
A little cooking oil down each drain before you leave prevents it: it floats on the water and slows evaporation considerably. It is the cheapest trick on this list.
Fridge, washing machine and small appliances
Empty the fridge, clean it and leave the door ajar. Closed and switched off for months it becomes a mould incubator. Same for the washing machine: door and detergent drawer open, filter emptied if the model allows.
Unplugging what is not needed cuts phantom consumption and, more to the point, takes appliances out of harm's way if there is a voltage surge during a storm.
Ventilation and damp
A house closed with no air change accumulates moisture, and that moisture settles on the coldest surface in each room. That is where the marks behind wardrobes appear, the ones neighbours mistake for a leak.
Leave internal doors open so air can move, pull furniture a few centimetres off external walls and, if you have ventilation grilles, do not block them. In properties with a recurring problem, a dehumidifier plumbed to a drain handles the whole winter.
Blinds, awnings and the outside
Retract the awnings. An awning left out through an autumn gust takes its own arm with it and sometimes more. Close the blinds fully, and if one is stiff it is better to know now than in April.
On the terrace, put away anything that can fly and clear the drain. It is exactly the same gesture we ask for before the rain, and here it does double duty.
Who opens the door if something happens
Leave a key with someone who can get in. It does not matter whether that is a neighbour, a relative or us: what matters is that if the flat below sees a mark in January, somebody can open the door before the problem grows for three months.
If nobody can, that is exactly what periodic maintenance visits with a report exist for.
