I didn't get what I was expecting out of this book, and I think the title is really a misnomer. This book is written really more as a reference for young and inexperienced designers looking to start their own business. Note the following:
The author is a GRAPHIC designer, not an interior designer. She (yes, "Theo" is a she) makes reference to interior design projects that are laughable--designing a carpet is not interior design. And just because it will be a vinyl applied to a wall, doesn't mean a logo design is interior design. Not being an interior designer, the author makes absurd comments about the industry that just aren't true (like that per-SF billing models are a bad idea. maybe for residential but for commercial design, per-SF is standard. And profitable). I just don't think the author is qualified to be writing this book.
Furthermore, estimating and budgeting are ONLY talked about in very generic terms. Basically, the author wants you to know that these are important things to do right, or you won't make any money. Unfortunately I think most readers already know these are important things, otherwise they wouldn't buy the book. But there are no specifics on how to calculate different types of materials, labor, processes. Nothing of real substance that the reader can take with them to the job and apply.
There are lots of contradictions and very astonishing ideas expressed by the author. For example, the author says to 'respect the client's personal time' by not contacting them outside normal business hours....but then suggests that when you have bad news to share, wait until the last possible minute, so that the client can think about it over the weekend. How is expecting the client to think about work on the weekend respecting their time?? Even if that is respectful, its still bad advice--the LAST thing you want to do is give the client time to stew about the problem. By Monday morning they're sure to be really pissed. She also says that over the years she learned NOT to take responsibility for her staff's mistakes. Um, HELLO!?!? A client hires the company, and as the boss, you do have the ultimate responsibility for everything every employee does. Her advice is the exact opposite of what a designer should do.
I might reference the forms in the back of the book, maybe some day. But overall this book just didn't offer me anything I can use. Might be better for someone who has only a year or two of work experience.