Sarah Jessica Parker is already planning for her children leaving home.

The 46-year-old actress - who has children James, eight, and twin daughters Tabitha and Marion, two, with husband Matthew Broderick - admits she and her spouse have lots of ideas of what they will do when they find themselves sharing an empty house in years to come.

Asked how they keep their marriage alive, she said: "We go to the theatre and to dinner and we occasionally see friends. And we talk a lot about when the kids are grown and gone and all the things we'll do."

The 'I Don't Know How She Does It' star also revealed her favourite way to unwind is by watching property programmes on television - but she has to wait until her children are asleep before she can tune in.

She explained: "It's really only when the children are in bed - and really in their beds, not their fake, pretending to be cooperative going to sleep, but when I hear deep breathing - that I have any free time.

"And what I do is watch 'House Hunters International.' It's not even a guilty pleasure- I make very public statements about how much I love it.

"They're just real people looking to buy a home or a holiday home and it's just fascinating. I cannot get enough of it.