Cats do not explore the way dogs do. A dog charges in, nose to the ground, tail going. A cat stops at the threshold and reads the room before committing a single paw. Put a cat into a full flat on day one and you have handed it a problem it cannot solve: too much space to map, too many unfamiliar smells competing for attention, no established safe point to retreat to. The one-room method works because it matches what the cat's own instincts are already trying to do.
Choose the right room and set it up before the cat arrives
A bedroom or a quiet study works better than a kitchen or a living room. You want low foot traffic, no appliances that cycle on and off unpredictably, and a door that closes fully. Set up everything the cat needs inside this room before you open the carrier: a litter tray in one corner, food and water on the opposite side of the room from the tray, a hiding spot at floor level, and a resting surface that is slightly elevated. A cardboard box on its side with a folded towel inside is enough of a hide. The carrier itself, left open with its door off, becomes a familiar-smelling retreat and counts as the hiding spot if you have placed a worn piece of your clothing inside it during transit.
What the cat is doing in there, and why it takes longer than you expect
For the first few hours, most cats will sit inside the hide and not move. This is not distress. It is information-gathering. A cat's primary sense in an unfamiliar space is smell, not sight. It is building a scent map of the room: where the litter is, where the food is, where the air moves, whether anything in here smells like a threat. Cats have scent glands on their cheeks, chin, forehead, and the base of their tail. When your cat eventually walks the perimeter of the room and rubs its face along the skirting board or the leg of a chair, it is not being affectionate with the furniture. It is depositing its own scent over the unfamiliar smells and claiming the space as readable territory. That process takes one to three days for most cats, longer for cats that have come from a shelter or a chaotic environment.
How to behave in the room during those first days
Sit on the floor. Do not approach the cat. Let it approach you. Read a book, work on a laptop, do something quiet that keeps you in the room without directing attention at the animal. Cats find direct eye contact from a stranger threatening. If the cat looks at you, blink slowly and look slightly away. This signals that you are not a predator sizing it up. Offer a hand at floor level if the cat comes close, palm down, fingers relaxed. Let it sniff and decide. Do not pick it up during this phase unless there is a medical reason to. Handling before the cat has chosen to approach you resets the trust clock.
Opening the rest of the home, one section at a time
There is no fixed number of days before you open the door. The signal is behaviour, not a calendar. When the cat is eating normally, using the litter tray without hesitation, moving around the room with its tail held upright rather than tucked, and initiating contact with you, the base room is mapped. Open the door to one adjacent space, a corridor, the next room, and let the cat choose when to go through. Do not carry it through. Leave the base room accessible at all times; it remains the safe point while the cat extends its territory. Add one new section every two to three days. Keep the litter tray in the base room until the cat is comfortable in the full flat, then move it incrementally toward its permanent position, a few centimetres a day. A sudden litter tray relocation after a cat has mapped its territory is one of the most common causes of litter avoidance in a new home.
When the settling-in process is not going to plan
Some hiding and reduced appetite in the first two to three days is normal. If your cat has not eaten at all for more than 48 hours, is breathing with its mouth open, is hiding with its body pressed flat rather than curled, or shows any discharge from the eyes or nose, contact a vet. Stress can suppress appetite in cats, but it can also mask illness that was present before the move. A cat that was healthy at the shelter or the breeder's home may have been incubating an upper respiratory infection; the stress of moving lowers immunity and the infection surfaces in the first week. This is common enough that many vets recommend a check-up within the first few days of bringing a new cat home, regardless of how the settling-in appears to be going.