Energy Audit Glossary

What Is A Weather Resistant Barrier

  There’s a great deal of functional overlap between materials that act as an air barrier, vapor barrier and as a weather resistant barrier. We’ve covered air barriers and vapor barriers in previous posts, but what is a weather resistant barrier? And what’s with the rest of the layers and barriers of your building enclosure […]


What Is A Thermal Barrier (Yes, That’s Your Insulation)

by Erik North on September 30, 2011

Post image for What Is A Thermal Barrier (Yes, That’s Your Insulation)

  What is the thermal barrier and why do we need such a fancy term for fiberglass insulation? And for a change, instead of five sentences of contrived SEO mumbo jumbo, let’s jump into it. What is The Thermal Barrier (Yes, I snuck in an SEO phrase) The thermal ‘barrier’ or enclosure or control layer […]


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 […]


What Is The Building Envelope

  I talk about it all the time but what the heck is the building envelope (or to use the more appropriate modern term, what is the building enclosure)? Why is the building envelope important? As a side note, I’m going to use the terms, ‘building shell’, ‘building enclosure’ and ‘building envelope’ interchangeably. Building scientists […]


What is EPS Foam

  What is EPS foam insulation (also called expanded polystyrene or bead board)? How is EPS foam insulation used in my home? What is the EPS foam’s R-value and how is it different from XPS foam (aka the blue boards in Home Depot)? And why do I keep saying ‘What is EPS foam’ instead of […]


Post image for Air Barriers – Another Wicked Important Part of Your Home

  Your home’s air barrier is that wall your sofa is pushed up against. Thank you, good night! Important note: First thing…air ‘barrier’ is a bit of a misnomer (and an outdated term). Barrier implies totally stopping something. Air barriers in no way TOTALLY stop air flow but rather there are varying degrees of air […]


What’s In a Name? Namely, Pascals…

by Erik North on September 2, 2011

Post image for What’s In a Name? Namely, Pascals…

  What are Pascals? We all know who Blaise Pascal is, often getting into rousing dinnertime conversations about the man over cognac aperitifs (OK, almost nobody outside university math and philosophy departments remembers him or drinks cognac). Blaise Pascal was a French philosopher, physicist and inventor. He was basically a French 17th century Batman. Pascals […]


What is ROI (Return on Investment)?

by Erik North on August 17, 2011

What is ROI (Return on Investment)?

  Working through these glossary definitions, it starts to feel like Acronyms R Us. And here’s another one. Return on Investment, abbreviated ROI, is where the nuts and bolts of weatherizing your home begin to put dollars back into your pocket. It’s a simple cause and effect relationship: Invest Money into Weatherizing –> Return on […]


What is ASHRAE (And, Yes, They Are Rocket Scientists)

  ASHRAE is a name I throw around a lot in the credits section of audits. And why not, they’re authoritative guys. But…who or what the heck is ASHRAE? ASHRAE is not a group of mad scientists, not matter what they think. The acronym stands for the American Society of Heating, Refridgeration and Air Conditioning […]


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. […]