It takes us an enormous amount of time to put a book like this together.
Also, this book is looking so good, and will be so relevant to so many people, that we want to take our time and do it well.
Here (today) I'm working on the most complicated two pages so far in the book. When I started I had no idea how it was going to come together (or if it would).
But starting did the trick; in over two days it worked itself out. 22 photos with fact-filled captions.
Here's an interview of me done a few months ago by Natalie So, where I talk about layout and beyond: http://www.editionlocal.com/lloyd-kahn-shelter-publications/?rq=kahn