Ready your envelope – Part 1 is an overview of the role of a tight building envelope.
“A house needs to breathe” is a cliche in the world of contracting that is just … false.
Why it matters: This is a way to describe a leaky house and a leaky house cannot maintain the cold or heat in your house like a tight house can.
⛏️ Dig deeper with Dr. Allison Bailes excellent book on this topic.
🥊 The bottom line: Your house first needs to be as air tight as possible, and then it needs adequate insulation.
🔭 Zoom out: The shell (envelope) of your living space is made of 6 sides —> the floor, the ceiling and 4 walls.
- The envelope is doing its job IF it resists the forces of nature.
⚙️ How it works: Let’s remember 3 laws from high school physics.
👉 Hot moves to cold
👉 Wet moves to dry
👉 High pressure moves to low pressure
🔬 Zoom in: Today, think about hot moving to cold.
- Replace the phrase “hot air rises” with “hot air moves to cold air”
- Example: Hot air in your attic is moving DOWN toward the cold air in your house
- Wherever your ceiling plane is NOT air sealed —> like around can lights
✅ For your Smart Homeowner list
- If you can’t adequately control the comfort in your home, the solution does not start with getting a new AC.
- Air seal first.
- Insulate second.
- Address HVAC third.