Rent - until you are in a position to either buy the size of house that will fit your needs long term or you are looking at staying for more than 5 years.

Houses are a long term investment. If you are only looking to own for 5 years, then you may want to consider waiting. That is unless you want to become a landlord and turn it into a rental when your family out grows it.

The problem with only 5 years, is most of your payments will go directly to the front loaded interest and you won't have added much if at all to principle or equity in the home. A lot could happen to the market in 5 years (could go up, down or stay the same). You've got to be careful and have a contingency plan if the market drops drastically. Go in with your eyes wide open.