I hear people often say that they've outgrown their house or they want to make big changes to their house and they're trying to make a decision about whether they should completely renovate or build new.
I think it's important to look at all angles before making that decision, Look at the cost of adding on to the house and will it make your house overpriced for your neighborhood. Will the addition change the character and flow of your house and make it a little awkward. People comment on the inconvenience of building, but this will last for 5 of 6 months and probably give you years of comfort and contentment. The cost of borrowing money right now is so low that it enables you to do things that you couldn't do 5 years ago.