Bring a light meter to every house you look at, and compare it to the light in the house you now live in.

Go and see houses when it's rainy, when it's dusk, when it's cold - as well as when it's nice.

Work out how hot or cold both families like to keep a place, in case one lot likes it tropical and the other arctic.

Make a list of ground rules on good manners for everyone.

Eat together at least once a week, at table, with nice music playing, both families.

Work out what is your absolute ideal house, for each family, and use the two ideals as guidelines.

Work out how you're going to dole out the rooms - who gets to divide, who gets to choose - and the same with kitchen space.

Try to get a place with two bathrooms and two car parking spaces.