We don't start with a product. We start with your SITE Score — then recommend the solution that actually solves the problem.
It's the barrier between inside and outside — and when it fails, your comfort, energy bills, and air quality all suffer.
The building envelope is everything that separates the inside of your home from the outside environment:
Most people think insulation is just about R-value — how thick it is and how much heat it blocks.
But the building envelope is a system. Insulation, air sealing, and vapor barriers all have to work together — miss one piece, and the whole system fails.
Thermal Barrier
What it doesSlows heat transfer between inside and outside — keeps your home warm in winter and cool in summer.
What people get wrongThey focus only on R-value and ignore air sealing. Air leaks bypass insulation entirely — you can have R-50 in the attic and still lose ~40% of your heat through gaps.
The right approachHigh R-value plus comprehensive air sealing.
Air Barrier
What it doesStops outside air — and the allergens, pollutants, moisture, and dust in it — from leaking in, and stops conditioned air from leaking out.
Why it's criticalIt's the single most important factor for indoor air quality. Building science research attributes 25–40% of heating and cooling energy loss to air leaks — more than any other factor.
How we do itSpray foam (insulation and air barrier in one), caulking penetrations, sealing rim joists, weatherstripping, and a continuous air barrier across the entire envelope.
Moisture Control
What it doesControls moisture movement through walls, floors, and ceilings — preventing the condensation inside cavities that leads to mold, rot, and structural damage.
What people get wrongThey skip vapor barriers, or place them wrong for the climate zone. The Bay Area spans several zones — coastal San Francisco isn't the same as inland Livermore.
The right approachClimate-appropriate placement, integrated with air sealing, designed to let the envelope breathe in the right direction.
Now that you understand what a building envelope is, here's how we design them. We use the SITE framework — a building-science approach that evaluates every envelope across four pillars: Sound, Indoor Air Quality, Temperature, and Energy. Every product we recommend and every assembly we design has to deliver across all four — not just one.
Most insulation companies sell products: spray foam, batts, blown-in. They'll quote you R-values and thermal resistance and leave it at that.
We don't work that way. We start with a building envelope diagnosis — a Comfort Scan for homeowners, a blueprint review for contractors — then design a solution using our SITE framework. Only then do we recommend the products that deliver those outcomes. Sometimes that's spray foam. Sometimes it's batts with proper air sealing. Sometimes it's a hybrid.
Four questions we answer before recommending anything:
The product serves the framework. The framework doesn't serve the product.
Closed-cell spray foam is excellent for air sealing and moisture control, but it's too rigid to dampen sound. For sound control you need open-cell foam or acoustic batts — and batts installed with gaps fail, because sound travels through air.
Batts don't stop air movement. Air — and the allergens and moisture it carries — moves through batts freely unless there's a separate air barrier. Most attic jobs skip this step entirely.
You can have R-38 in the attic and still have a hot upstairs bedroom if there are air leaks, thermal bridges through framing, or ductwork in unconditioned space. Temperature control needs air sealing + continuous insulation + proper installation.
The highest R-value insulation won't lower your bills if the envelope leaks air. Efficiency takes air sealing first, insulation second, then addressing thermal bridges and ductwork in conditioned space.
Here's how each option performs across the four pillars — so you can see exactly why we recommend what we recommend.
Sound + Air Barrier
A lighter, more flexible spray foam that creates an air barrier but stays vapor-permeable.
Vapor-permeable — may need a separate vapor barrier for moisture control.
Air + Vapor Barrier
Two-part polyurethane foam that expands and hardens — an air barrier, vapor barrier, and thermal barrier in one application.
Too rigid to dampen sound — not the choice for sound control.
Batt Insulation
Pre-cut insulation panels installed between studs, joists, or rafters.
Blown-In
Loose insulation blown into attics or wall cavities.
Foam Board
Foam panels installed as continuous insulation over exterior walls or under siding.
Tell us the problem. We start with a diagnosis, then recommend the right approach — no product-pushing.
