I haven't added on, but I have done some remodeling within the same 4 walls. Get recommendations from other folks, esp. folks who've had that kind of work done.

Try to make a list of EVERYTHING you want or wish for-- then organize it by what you can include. Also take a stab at figuring out the critical path for the work, before you talk to the contractor. And have a budget, even if you have to modify it later.

And then smile and relax. It won't take forever. It'll be done before you know it.

Maryanne