Building Science on Steroids
Building Science is a burgeoning profession that deals with the analysis and control of physical phenomena affecting buildings. It has come of age, at least partially, because of an onslaught of modern building failures leading to health concerns and premature building demise. Much of this failure, even in the Desert Southwest, is due to moisture intrusion in one form or another.
On this Island in the Pacific Northwest, I have just witnessed more rainfall in one month than Santa Fe sees in a wet year! Here one can really grasp building science concepts while observing nature on steroids. Even asphalt shingles sport living roofs in a few short years and many buildings, when left unattended, fall to ruin before one’s eyes.
In a rain-forest, a little inattention during construction, say a faulty perimeter drain or a bad flashing detail can begin the process of water intrusion and ensuing mold. Simple lack of maintenance can also be the catalyst…an overflowing gutter clogged with pine needles will soon wreak havoc. Even a minor lapse in occupant upkeep, like failing to dry out the washing machine after use, can cause mold to grow within a few hours. It seems obvious that different climates call for different levels of response. Doesn’t it?
I once partook in a group conference call where two of the country’s lead building scientists dominated the conversation; one from his headquarters in North East and the other in California. While neither of these men is particularly known for humility and tact, an actual screaming match ensued between them. It ended abruptly when they simultaneously hung up, each rushing off to catch their respective planes, on their way to be keynote presenters at two different inter-national conferences. (I am not kidding!). While NE had argued that it was impossible to get enough air exchange in a healthy home without mechanical ventilation Cal argued that mechanical ventilation was completely unnecessary, prone to breaking and ridiculously high in embodied energy. These two guys, the top dogs in the field, were far from consensus on this important issue. The rest of our IAQ team was rendered speechless in the wake of this drama which had momentarily shattered the shared sense of purpose, mutual respect and cooperation with which we had all worked prior to being graced with these star appearances.
As the years have passed, I have heard this sort of argument, oft heatedly repeated, both sides invoking the hallowed name of Building Science. I have come to think of the dilemma as one of blind-sided opinion, not fact. In the case of the conference call, while one blind man was examining the tail of the building science elephant, the other had his hands on the moist snout. Who was correct? They both were from within their limited context. Although the laws of physics behind building science may be immutable, the building responses must vary based on local conditions and materials.
An airtight conventional light frame building with vapor barriers and inoperable windows should absolutely have mechanical ventilation, even in Santa Fe. However, one with thoughtful design, good thermal mass, non-toxic construction, windows that open, occupants with common sense, and a wall system with excellent hygric bearing capacity (ability to handle moisture) may not call for mechanical ventilation, especially in Santa Fe, for all the reasons that Cal so vehemently argued.
While hiking on the island I come across a heritage building created long before modern-day mechanics. Why has this man-made Hunza thrived while so many of its contemporaries have long ago decomposed? I am awestruck and inspired by the lineage of building wisdom that is so gracefully embodied in this silent teacher.