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One important nuance for anybody reading this and drawing conclusions about their own cat: purring is not only a sign of contentment.

Cats also purr when stressed, injured, unwell, giving birth, and sometimes when dying. This surprises people badly, and it matters because a purring cat at a veterinary practice is not necessarily a comfortable one. We see it constantly.

The usual interpretation is that purring is a self-soothing behaviour as well as a social one — there is a well-known hypothesis that the frequencies involved may have some restorative effect, though that is a hypothesis rather than an established fact.

So read it in context. Purring while relaxed, kneading, half-asleep on your lap, is contentment. Purring while hiding, hunched, off food or reluctant to move is a reason to phone somebody.

One thing genuinely worth noting: a change in purring pattern can be information.

A cat that suddenly purrs far more than usual, or one that stops purring in situations where she always did, is showing a change in behaviour — and in cats, behaviour changes are often the first and sometimes the only sign that something is wrong. They conceal discomfort extremely well.

Not a reason to worry about a loud purr. A reason to notice if it changes.

Worth stating what is not a lesson, since people often draw it: a 25% fall does not mean you were wrong, and a 25% rise would not have meant you were right.

Over short periods the outcome tells you very little about the decision. That is uncomfortable and it is the reason judging decisions by results is such a reliable way to learn the wrong thing.

Judge the process. The concentration and the timing are criticisable regardless of what the price did.

Speaking from what we see rather than from principle: the specific situation you describe is one I would not allow, and the reason is the setting rather than the general question.

A cat who has roamed in the countryside has learned that environment — where the roads are, where the boundaries are, how to get home. Moved to an urban building on a second floor with a shared entrance, none of that knowledge applies. He does not know the roads, does not know the territory, and does not have a reliable route home.

The first weeks after a move are also exactly when cats go missing, because they have no established territory and will often try to travel back to the previous one.

So whatever you decide long term, the immediate answer is a period indoors while he settles — several weeks at minimum. That is standard advice after any move and it is not a permanent decision.