Thinking about adding on? There are a few important few things you should consider before getting started: Hiring professionals; be sure you hire an architect before hiring a builder. The addition should look as if it was a part of the original design. Also, thoroughly research prospective professionals before you hire them. Cost; have a clear idea of your budget, but, be realistic. A good resource is CostHelper.com; this site will help you roughly estimate the cost of the project. And finally, prepare yourself for a mess, people will be in and out of your home; it will be noisy and inconvenient at times but, in the end it will be worth it. More here