Keeping a new kitten inside

[Brabant93]

We have a 1 year old cat who will only go outside if we keep the kitchen door open. We have just adopted a kitten, and I am wondering how I can keep it from going out. I was thinking of one of those fireplace guards to put over the door entrance. We spend most of our time in the kitchen/ family room so do not want to keep the kitten out of there.

We also have sash windows. Any ideas what I can do to stop the kitten going out of them? Thanks.( any tips on how to get the two to be friends also welcomed!! )

As a starter, feed them at the same time in the same room, but never force them to share a space.
They may never actually become friends.

i have similar problem in that i like to keep the back door open but can't due to having a new kitten that can't go out. hate keeping the door shut, also don't like having to keep her in although so far she is showing no signs of beign interested in going out but she is only 4 months old and hasn't been neutered yet. i have to shut her out of the kitchen/back room (as there is no dividing door) whenever i do have to briefly open it, i guess you will have to do the same unless someone comes up with something else. i will be watching to see if someone has any good ideas...

I'm probably missing the obvious but screen doors and ont the window?

For the cat to go out but not the kitten: microchip catflap?