One of the first steps in designing a project is figuring out the program. This is just a written list of the spaces along with anything that may be known about them. Sometimes it's pretty simple:
"We'd like to add a master bedroom and bath. The bathroom should have a shower but we don't need a tub." "Oh, and we'd like two sinks in the vanity."
Sometimes it runs for pages and pages with detailed room descriptions and adjacencies. The program for the project I'm working on right now is a little over two pages and includes everything that the client could think of as well as everything I could think to ask. The project is a house of only 1500 square feet so it's pretty detailed. My clients for this house are artists as well as dedicated cat people so one interesting wrinkle in this problem is controlling access to various parts of the house for the felines.
That's right. This morning I'm herding cats.