Start with the draughts, not the thermostat

Before you reach for the thermostat, spend an afternoon finding where the cold actually gets in. British homes lose far more heat through uncontrolled draughts than through the walls, and a roll of foam strip does more for comfort than turning the dial up a degree. Work round the house with the back of your hand on a breezy day — it is more sensitive than you think.

The usual suspects, roughly in order of how much they matter:

• Letterboxes and keyholes. Brush seals and a keyhole cover cost very little and stop a surprising gust.
• Doors. Check the bottom edge and fit a brush or rubber seal. A fabric draught excluder is fine for a while, but a proper seal lasts.
• Sash and casement windows. Foam or brush strip works on the frame. On an old sash window, don't squirt sealant into the gaps — you will regret it when the window needs to move. Use removable seals instead.
• Chimneys. An open flue is a hole in your roof. A chimney balloon makes an enormous difference — just remember to remove it before the first fire.
• Floorboards and skirting. Fill gaps between boards, and where skirting meets floor, with flexible wood filler, or cover them with a heavy rug. Check the small holes around pipes entering walls.

Windows, curtains and the gaps you forget

Autumn is the moment to think about curtains properly. Lined curtains, hanging below the sill and ideally to the floor, hold warmth in far better than a thin pair that stops short. If you have a bay or a large window, consider thermal linings or a second pair on a separate track. Close them at dusk, when there is no point heating a room that is losing warmth through a sheet of glass, and open them again in the morning to let the sun do some free work.

Two other spots are easily missed. The loft hatch is often a bare board with a gap around the edge; a length of draught strip and a piece of insulation glued to the back of the hatch makes a real difference. And extractor fans in kitchens and bathrooms that lack a backdraught flap will let cold air in all winter — a cover or a replacement unit with an integral shutter sorts it.

Refresh the bedding before damp evenings arrive

There is nothing like the first properly cold night to make you regret a thin summer duvet. As a rule of thumb, 13.5 tog suits most British bedrooms; drop to 10.5 tog if yours runs warm, or go to 15 tog for a cold, north-facing room. If your duvet has gone flat and lumpy, replacing it is money well spent.

• Wash and air everything. Duvets, pillows, mattress protectors and blankets all benefit from a wash before the season, checking care labels first.
• Replace tired pillows. If one folded in half doesn't spring back, it has had it.
• Layer rather than overheat. A wool or brushed cotton blanket on top of the duvet lets you adjust through October's swings.
• Air the bed each morning. Pull the covers back for half an hour — it costs nothing and does more for damp bedding than any spray.

Swapping cotton sheets for flannel, and putting a hot water bottle in ten minutes before bed, is old-fashioned comfort that costs pennies.

Deal with damp and condensation early

Autumn's warm days and cold nights are the perfect recipe for condensation. Water running down the windows in the morning is a warning, not a quirk of an old house. Left alone, it feeds mould on reveals, behind wardrobes and in north-facing corners.

• Ventilate deliberately. Open trickle vents, use extractor fans, and open a window for ten minutes after a shower or while cooking.
• Keep moisture out. Lids on pans, washing dried outside or in a ventilated room, and gutters cleared before the leaves come down.
• Use a dehumidifier. An afternoon's running in a damp bedroom pulls out a surprising amount of water; moisture absorbers help in wardrobes.
• Never block air bricks. They exist for a reason, and blocking them causes far worse problems than a draught.

Then walk round the outside of the house: clear the gullies, check for slipped tiles, and make sure the drain by the back door is not already full of leaves.

Store the summer, welcome the winter

Summer cushions and throws need more than being shoved in a cupboard. Clean them first — body oils and spills are what moths are after — and make sure they are bone dry. Cotton and linen are happy in vacuum bags or plastic crates; wool, feathers and natural fillings need a breathable cotton bag or a cardboard box with a few cedar blocks or lavender sachets. Store everything off the floor, never in a damp garage or fusty cellar.

Bring the winter textiles out at the same time: wool throws, heavier cushions, velvet covers. Air them on the line on a dry day before they come back into the sitting room.

Get the fire ready before you need it

Nothing says British autumn like the first fire, and nothing spoils it like a smoking chimney. Book a sweep now, before the November rush. If you burn wood, order seasoned hardwood with a moisture content below 20 per cent — kiln-dried logs are reliable — and stack it off the ground with an air gap around it, under cover but not sealed up. Remove the chimney balloon. On a woodburner, check the door rope and clean the glass; on an open fire, clear the ash and check the fireguard.

Do it in September and the first cold evening feels like a pleasure rather than a scramble.