How about double air locked cat flap i.e. into and out of a porch.

Even the best cat flaps are draughty, and can as you say be blown open by the wind.

Even fully open they could represent only a very small proportion of the air leakage area of a house that passes current building regs

What do you mean by air tight?

Cats can operate simple levers, we've all seen them flush the dunny, Maybe a lever with a slight cam on it.

I was awoken on christmas to people talking in our lounge it scared the S***e out of me, our cat had opened a toy tractor and it was singing old McDonald. Scary stuff those nursery rhymes.

Posted By: CWattersWoke up early in the mourning

Nothing worse than falling asleep in a funeral ;)

Paul in Montreal.

Hi Stuart, Are you going to incorporate a buffer space/corridor into your ESH? A porch at one end would make sense with a double cat flap.

I've just installed a 'Pet Porte' cat flap that reads the microchip in the cats neck (so no collar required).
The flap itself is fairly robust compared to my old Staywell one and while not 'sealed' as such is fairly snug fitting. It's also magentised at the bottom - it would take a fairly strong direct gust to blow it open in my opinion.

I haven't got a cat now, as it died some years ago. However, when the cat came in and out there was always the issue of drafts, but the thing that annoyed me more was that the cat would rush in at 5 a.m. and then run up the stairs, and the noise would often wake me up. So I would opt for a "silent" cat flap, if one was available.

On a plus point I came across some info that a cat emits about 11W of heat. So you can design that out of your heating system ;-) If your cat is an indoors type in the winter it might go someway to compensating for the ventilation losses. Although I think for the same heat output, natural gas or even LPG is probably a lot cheaper than Whiskas cat food.

You could design a spring loaded cat flap which makes a good seal with the door. This would allow the cat to get out for doing you know what, but it would have to wait till you get back home to come back in and so you'd need to make him a little eco yurt in the back garden.

Have you though about a hamster instead? You could run a small LED light off a dynamo attached to the wheel :-)

Simon

Our puss uses the cat flap as a gloried door knocker. He bats it and bats it and eventually we give in and come and open the door for him. I'd not given the heat loss a thought. If we made him run around a lot would we get more than 11W of heat to pay us back?

Our cat can not use a flap even after 12 years. We bow down and open the door every time. I did do plans for a flap that 'slides' when pushed and closed after a period of time (magnetic or spring). This made a better seal. I am in the process of a new build design and an extension and would love to try this out, problem is the electric or battery power circuit required, oh and the cats age. Regarding pressure testing does any one know the difference as tests are commonly done on front doors and flaps are on the rear and new builds never really have a cat flap installed.

How did we get from airtight house to shaving pussies?