Readiness is a pattern, not a birthday
No age automatically makes a young dog safe loose in the house. Readiness is a cluster of behaviours shown consistently over weeks. The core signs are these: he is reliably house trained, asking to go out or holding comfortably for the length of absence you plan; he chews his own toys rather than furniture, shoes, or cables when bored; he can settle and nap while you are home but occupied, instead of shadowing you constantly; and departures do not trigger panic, frantic scratching at doors, or sustained barking. One brilliant week after a tiring holiday is not the pattern. Look for ordinary-day evidence.
What his behaviour around the house tells you
Watch how he spends unstructured time when nobody is entertaining him. A dog who amuses himself with a chew, moves between resting spots, and greets your return from another room with mild interest is rehearsing exactly what alone time will look like. A dog who counter-surfs the moment you shower, raids bins, mouths skirting boards, or cannot settle unless touching you is telling you he still needs management, not freedom. Also note his behaviour at windows and doors. A young dog who escalates at every passer-by may spend your absence rehearsing that arousal, which is unfair to him and to your neighbours, however tidy he leaves the cushions.
Test in stages you can verify
Start smaller than your ambition. First, leave him loose in one dog-proofed room while you are elsewhere in the house, then for a short trip out, fifteen to thirty minutes, and build duration gradually as each stage comes back clean. Dog-proof honestly: cables, shoes, bins, laundry, and anything chewable or swallowable out of reach, his own chews and water in place. On return, check the evidence calmly, toilet accidents, chewing, moved objects, signs of distress such as drool-soaked fur or a scratched door, rather than only asking whether the room looks tidy. A cheap camera, if you have one, answers the distress question better than guesswork.
Setbacks are information, not failure
If a stage fails, a chewed table leg at forty minutes, an accident at an hour, step back to the last duration or setup he managed and rebuild more slowly. Do not punish damage found after the fact; he cannot connect your anger to the chewing, and it only makes homecomings tense. Many young dogs manage one room long before they manage the whole house, and many regress briefly in adolescence when chewing returns with adult teeth settling and independence rises. Treat that as a normal stage to manage with gates and supervision, not as proof he can never be trusted.
When loose is still the wrong call
Keep using a crate, pen, or managed room if he is teething heavily, has a history of swallowing objects, panics when left, or shares the home with things he cannot resist, such as open access to another pet's food or a cat who torments him at the window. Also pause freedom after illness, a house move, or a new pet arriving, since even a proven dog deserves a reset after big changes. If alone-time distress is the blocker, work on gradual departures and speak to your trainer or veterinarian, because freedom will not fix anxiety; it just gives it more room.
A shared record of what he has passed
Households undo good staging when one person leaves him loose 'because he seemed fine' beyond the stage he has actually passed. Recording each trial, room, duration, and what you found on return, keeps everyone honest. Through KinsLe Care Teams you can log your young dog's loose-house trials as completed steps, so the freedom he gets matches the readiness he has genuinely shown.