The Envelope: Build Tight. Ventilate Right
You wouldn’t leave your front door cracked open all day — so why let your walls, roof, and attic leak air and energy 24/7?
That’s exactly what happens in most homes. Behind the drywall and siding of a code-minimum house is an envelope that’s full of unsealed gaps, poorly taped seams, and penetrations that act like tiny chimneys. Warm air escapes in winter, cool air leaks out in summer, and unfiltered air filled with mold, dust, pollen, smoke, and moisture finds its way in year-round.
That’s bad for comfort. It’s bad for your utility bill. And it’s really bad for your health.
The solution? Build tight. Ventilate right.
What Is the Building Envelope?
The building envelope is the physical shell of the home — the exterior plywood walls, the roof deck, seals around windows, and the foundation — that separates the conditioned inside from the unconditioned outside. It’s your home’s first and most important defense against weather, noise, pollutants, moisture, and energy loss.
If the envelope is weak, everything inside the home suffers:
The HVAC works harder
The air quality drops
Drafts become constant
Mold can grow where moisture sneaks in
Comfort becomes inconsistent from room to room
Why Airtightness Matters
The tighter the envelope, the more control you have. You decide what air comes in, what goes out, and how the home performs. That’s the purpose of a blower door tests to measure air leakage. It’s not just a performance metric — it’s a commitment to health and efficiency.
A leaky home is like driving a car with the windows down and the A/C blasting. You’re wasting energy, reducing comfort, and inviting pollutants inside.
The Solution to Exterior Envelope: ZIP System Sheathing
The conscience builder doesn’t use traditional OSB or house wrap to create our walls. We use ZIP System sheathing — a structural panel with an integrated weather barrier that gets taped at the seams to create a continuous air and water barrier.
Why ZIP?
It reduces air leakage dramatically
It simplifies waterproofing
It’s durable and mold-resistant
It eliminates the guesswork of house wrap installation
When properly installed, it creates a sealed, continuous envelope that forms the foundation for everything else we do.
Ventilating Right: ERVs and Mechanical Fresh Air
Once a home is built airtight, it has to be ventilated properly. That’s where traditional builders often fall short. They seal up the house — but forget to add back a balanced system for bringing in fresh air and exhausting stale, polluted air.
That’s where Energy Recovery Ventilators (ERVs) come in. ERVs:
Continuously pull in fresh, filtered air from outside
Remove stale air from bathrooms, kitchens, and laundry areas
Transfer heat and moisture between the two airstreams to maintain comfort and reduce energy loss
With an ERV, the air in your home stays fresh, but your heating and cooling systems don’t have to work harder to recondition it. You get comfort, energy savings, and improved indoor air quality — all at once.
Build Tight, Ventilate Right: It’s Not a Slogan — It’s a System
The old way of building let homes “breathe” through cracks in the framing, leaky windows, and drafty attics. That kind of breathing brings in mold spores, pollutants, wildfire smoke, and humidity — and lets out comfort.
The new way is smarter. We seal the envelope. Then we add intentional ventilation through ERVs and range hoods with dedicated makeup air. We use MERV 13+ filters and balanced airflow in each room to maximize comfort.
This approach allows us to control:
Temperature
Humidity
Airflow
Filtration
Energy use
All of which leads to the three things every homeowner wants: comfort, health, and lower bills.
