'A House Needs to Breathe... or Does It?' Is Essential Building Science Reading

It is customary among book reviewers that one does not give away the plot of a book in the review and eliminate the need for anyone to buy it for the denouement. But a new book by physicist and building expert Allison Bailes III begs the question right in the title: "A house needs to breathe... or does it?" It proceeds to answer it on page 23: "A house does NOT have to breathe."

I mean, really, no suspense whatsoever. Why continue?

Possibly because it is the most entertaining and accessible book yet written about the arcane world of building science, covering everything you need to know about how a house works. In many ways, it is an odd duck of a book, both readable and technical. Who is it for? Bailes tries to explain in the preface:

"Is this book for you? Maybe. It's not a book for absolute beginners in building science, although you can still get a lot out of it if you are. And it's not an engineering textbook, although engineers will use it. The kind of person who will get the most from this book is a residential building professional (architect, engineer, home builder, trade contractor, real estate agent, home inspector etc.) an owner-builder, a do-it-yourselfer, or a motivated homeowner. it will help to have some kind of technical background or aptitude."

It might help, but it certainly isn't necessary if you are interested in the subject, and anyone considering a new home or fixing an old one will get the technical background they need. Take a technical subject like the difference between absorption and adsorption.

I never quite had it figured out until I read Bailes' explanation:

"Something that is adsorbed sticks to the surface. Something that is absorbed, on the other hand, is pulled into the volume. A pie thrown in your face is adsorbtion. A pie you eat is absorption." That is an analogy I will never forget.

Bailes has always been good at explaining complex concepts in a way anyone can understand. The most notorious example is his explanation of mean radiant temperature, the understanding of which is critical to designing comfortable spaces. Bailes titles his explanation "Naked People Need Building Science" and includes an illustration that probably killed his Google ranking for life, but as one reader noted on my post on the subject, "Thanks, Allison Bailes, for the link to the man in socks jumping on a bed in front of a window in a green room. I don't think I'll ever forget that image." With words and images, Bailes can explain the toughest concepts.

And explain he does, starting with what gives us a healthy and comfortable home, and basic questions like "what is energy" and even "what is the purpose of a house?" He then moves through the building enclosure, understanding moisture, controlling liquid water, controlling air, and controlling water vapor. Bailes' expertise is in mechanical systems, so there is lots of down-and-dirty about ducts and ventilation.

Throughout the book, Bailes stresses the importance of the building envelope, and the importance of reducing demand first. "Reducing the energy used by homes is more important than adding photovoltaic modules to generate electricity, especially if you can do so with reduced embodied carbon."

He is not throwing technology at the problem, but picking up on Engineer Robert Bean's approach: "Design for people, and good buildings will follow." It is always surprising how few people get this. He dislikes "rules of thumb" and hoary myths like breathing houses but doesn't bury the reader in psychometric tables and charts. It won't teach you how to do heat loss calculations but will teach you why they are important.

In the conclusion, Bailes nails the real importance of this book. "We don't all have to become experts in building science. But we need to know enough to find the right companies to design, build, maintain, and remodel our homes."

This stuff can get complicated, and very few professionals or trades have a handle on it all. Yes, you should seal a house tightly, but then you have to figure out how to control the air inside. Bailes summarizes the whole book in the last sentences: "There's at least one thing you should feel confident about. A house does NOT have to breathe. But people do."

Writing a book is hard, and so is publishing them. Remarkably, Bailes has done this book mostly on his own, without a traditional publisher. So much work went into this, and it may well become an essential text in the industry as well as the Allison Bailes III retirement fund. Put it on a shelf next to "A Pretty Good House," and you are covered in basic home design and building science. It's available from the Energy Vanguard Store.