"Don't forget the kids. A tree house at the bottom of the garden will free up valuable space inside."

"Millie spends hours playing out there. One day it's a castle, the next a cafe. It's great for her imagination"

Alison and David Slade commissioned Treehouse Life to build a treehouse for their daughter Millie, four, at the bottom of their 300ft garden in Highgate, London.

Q “What was there before?”

A “Nothing really. Just a mass of nettles and ivy. The garden was very overgrown.”

Q “How long did it take?”

A “About three weeks. they brought the materials in and built it all on site.”

Q “How much did you spend?”

A “It cost about £12,000 including lighting and installation.”

Q “Was it worth it? Does Millie actually use it?”

A “Absolutely. All the time. One day it's a castle, the next it's a cafe - it's great for her imagination. It's actually freed up space in the house, as we keep most of her play things out there now.”

Q “And do you use it yourselves?”

A “I'm not sure we'd be allowed to!”