Proofing expires as fast as he grows
The mistake most owners make is treating puppy-proofing as a weekend project completed before the puppy came home. A small puppy threatens skirting boards, low cables, and anything on the floor. A few months later the same dog can surf a kitchen worktop, open a pedal bin, reach a bathroom shelf, and put front paws on a table that previously functioned as a safe surface. Proofing that is not repeated on his growth schedule quietly becomes decoration.
Set a rhythm of re-auditing roughly every month, and sooner after any growth spurt or the first time he surprises you with a new reach, a stolen item from a surface you thought was safe is the clearest possible notice that the audit is overdue.
Audit each room from his new height
Literally change your viewpoint: kneel or sit so your eyes are at his standing head height, then look for what his nose and paws can now touch, and what he could reach standing on hind legs, since that is the reach that matters for worktops and shelves. In the kitchen, that means food, knives, medication, cleaning bottles under sinks without child locks, and bin lids he can now lever open. In the bathroom, it means medicines, razors, and toilet cleaners that have moved from theoretical to reachable, plus a toilet lid that should stay down for a taller drinker.
In living areas, check dangling charging cables, curtain cords, low shelves holding remote controls and batteries, and houseplants whose leaves are now within grazing range and may not be safe to chew. In bedrooms, look at bedside tables, where painkillers, coins, and hair ties live at exactly the height a growing puppy investigates first. Move the hazard rather than training around it wherever you can: latched cupboards, higher shelves, closed doors, and lidded bins beat vigilance, because vigilance lapses the first time the doorbell rings.
Boldness is a hazard category of its own
Height is only half the change. A bolder puppy tests things a cautious one ignored: pushing at stair gates, shouldering doors that do not latch, counter-surfing in the seconds you leave a room, and chewing skirting or furniture as teething pressure peaks. Test your gates and latches with a firm push of your own, because a gate fitted for a small puppy may fold under a determined adolescent leaning his full weight on it.
Supervision rules need updating alongside the hardware. A room he could roam while you cooked, when he was small enough to contain behind a cushion barrier, may now need a pen, a lead anchored nearby, or a closed door. Equally, give him legal outlets at his new size: larger chews he can work on, toys rotated before boredom drives invention, and enough exercise and training that his boldness spends itself on the day rather than on your baseboards.
Make the checklist a household habit
Walk the rooms with the rest of the household during each re-audit, because the person who always leaves shoes by the door or tablets on the coffee table is rarely the person who did the proofing. Agree where the risky small things now live, batteries, medicines, hair ties, socks, and treat any item stolen from a new height as a prompt to re-check the whole room, not just retrieve the item.
Keep the current version of the list somewhere everyone actually sees it, and update it the day anything changes, such as a new plant, a lower shelf in use, or medication moving rooms. Recording each room's new hazards and the agreed storage spots on KinsLe through Family Sharing means the whole family, including visiting grandparents and sitters, works from the same up-to-date safety picture as he keeps growing.