Interior Air Quality

Journal of Poor Homebuilding v.2

by Erik North on May 12, 2012

Post image for Journal of Poor Homebuilding v.2

    Week two…this isn’t poor homebuilding so much as former best practices that didn’t turn out. Asbestos at one time was a miracle substance. Great insulator, nearly indestructible on a residential scale and fire impervious. I mean, stone fibers don’t exactly light with a matchstick. Here’s the photo. From an energy history standpoint, this […]


What is Dew Point?

by Erik North on December 16, 2011

What is Dew Point?

  I’ve mentioned dew point in passing many, many times. You can tell from the name it has something to do with moisture. And moisture is a problem flash point in homes so it might be worth knowing a bit more about dew point. So what is dew point? How is it a driver of […]


What is Humidity (And How it Affects Your House)?

by Erik North on November 23, 2011

what is humidity

  The building envelope is the border between your comfy indoors and the chilly/sweltering outdoors. I say this a lot. The building shell controls the air, heat and for the purposes of this discussion, the vapor controls retard moisture flows in the house. Humidity in the air affects people, paper, the wood, concrete and OSB […]


Zonolite insulation, vermiculite

  I know…you’ve been just salivating for my big ‘What is Zonolite’ post. In a recent energy audit, we discovered a fair amount of asbestos and vermiculite. And by a fair amount, I mean almost all of it in Maine. The house had asbestos siding, asbestos pipe wrap, asbestos furnace wrap, asbestos floor tiling, loose […]


How Do I Control Humidity In My House?

by Erik North on November 5, 2011

Post image for How Do I Control Humidity In My House?

  I get a few funny looks during audits when the conversation turns from insulation to water and moisture control. But the two are interconnected whether or not it is obvious. Your entire house is made of wood, paper, concrete and plastic. Every one of those materials either holds loads of moisture or stops it. […]


what is stack effect

  Second question first, it’s just when I’m most productive in my writing. If you’ve ever seen an eagle or other large bird gliding above a canyon’s warm air flows, then you can understand the stack effect. The eagle is taking advantage of the warm air that flows up between the canyon walls and buoys […]


Post image for Should I Insulate My Basement (We Answered How…Here’s The Why)?

  I realized while writing a radon post last week that I’ve addressed in some detail ‘How’ to do certain insulation projects, but not why. I mean other than insulation as an unalterable good like U.S., apple pie and being able to DVR Red Sox games. Which for energy auditors, it is. But seriously…should I […]


Post image for What is Radon (Yes, It’s Radioactive…No, It’s Not A Godzilla Villain)?

  What is radon? Radon is one of those New England boogie phrases like ‘standing water’ or ‘Olympia Snowe’. Just frightening. But what is radon and why do your neighbors insist on mitigating it? Yes, What is Radon – Your Wiki Style Answer Radon, despite sounding suspiciously like a Godzilla movie character, is a radioactive […]


Post image for Should I Insulate My Basement With Fiberglass (Or Don’t Make Me Beat You With a Stick)?

  I thought this could use some expansion from when I wrote about basement insulation in a previous post. Sometimes homeowners, visions of Man Caves dancing through their head, can be gung-ho about tackling their basement remodeling projects. Bombing back from Home Depot, they trundle back home with a mash of 2x4s, wiring, sockets and […]


What is The BTL (or the Building Tightness Limit)?

What is The BTL (or the Building Tightness Limit)?

by Erik North on August 13, 2011

  What is the Building Tightness Limit? Which is really just an energy auditor way of asking, “Doesn’t my house need to breathe?” What is the building tightness limit? What does tightness measure and why is it important? The Building Tightness Limit (BTL) does not measure structural tightness or how well the building is constructed. […]