One of the big problems with indoors cats is that they frequently prefer to be outdoors cats and keeping them in when they want to be out can be, well, a bit tricky. As anyone who has attempted to keep a cat in can attest, they are very good at slipping unnoticed between legs, jumping out through windows you didn’t think they could reach, or squeezing through gaps you could have sworn were too small.

When my parents got Castor and Pollux, they attempted to kitten-proof the garden so that they couldn’t roam. That worked well whilst they were little, but eventually they figured out how to get around the strategically positioned chicken wire. No matter how hard my dad tried to find and plug the holes, they would find a way through.

Cassie, in particular, has a love of roofs and will leap from roof to roof, all the way down the road.

All three cats, Cassie, Polly and Fflwff, also have a fascination bordering on the obsessive with the front door. Given the opportunity, they will make a run for it, hiding out under the car or disappearing off into next-door’s garden before you can blink. Indeed, I think they believe the front door to be the gateway to Shangri La, so keen are they to get through it.

If my parents had a porch, however, they could use it a bit like an airlock, closing the inner door before opening the outer. That would prevent the usual cat location and head count ritual prior to each leaving of the house, and would make accepting deliveries and guests a much simpler process.

(If my parents sound a bit obsessive themselves, I can forgive them. They’ve had so many cats die in car accidents they are very protective, although they are easing up a bit now that they’ve realised that not only do they live in a much safer neighbourhood now, but also that the kittens can out manoeuvre them nine times out of ten.)

If you’re really serious about keeping your cat inside, though, a utility or mud room can fulfil the same function for the back door, allowing you to ensure that kitty never gets anywhere near slipping past you. I like the idea of a mud room - a place to take off muddy shoes, hang up wet coats and dry umbrellas. Kev’s very keen on the outdoors, so one day, a mud room is going to be essential.

But what about windows and patio doors? In the US, they use screens to keep out flying insects, but they can also keep in recalcitrant moggies intent on experiencing the great outdoors. I’m not overly keen on the look of screens, however. They do rather ruin the view, so if we move over there I’ll have to find some recessed screens that I can hide away in the wall when they are not being used.

It may sound a bit over the top, but if we are going to be serious about having happy and healthy indoors cats, then we need to plan for these everyday realities. And it’s far easier to include a porch, mud room and screens in the original design than it is to add them later when you realise how useful they’d be.