Performance-Path Wall Assembly Reference Library

700+ Verified Wall Assemblies. One-Time Purchase. Lifetime Access. Free Updates Forever.

You Cannot Size HVAC Equipment Without This Number.

Most builders don’t have it. Their clients are paying for that mistake every single month — for the next 100 years.

Every HVAC system ever installed in every building in North America was sized using a Manual J load calculation.

That calculation needs one number above everything else — the true whole-wall U-value of your assembly. Not the insulation label. Not the stud spacing. Not the code minimum.

The actual, verified, layer-by-layer thermal performance of the wall you built.

If that number is wrong — or missing — everything downstream is wrong.

An oversized system short-cycles. It never properly dehumidifies. Humidity collects in places you cannot see. Mold follows. Equipment wears out in half the time. Energy bills stay high — not because the envelope failed, but because nobody gave the mechanical contractor the right number before they sized the system.

This happens every day. On good buildings. Built by good builders. Who simply didn’t have the data.

Once the walls go up — that mistake is locked in. Forever.

I Spent 50 Years Watching This Happen.

So I spent six months fixing it.

I am Brian Iverson — former Certified Energy Auditor, journeyman carpenter, designer of 750+ homes, and founder of Carbonless Inc.

I built this library because the number every Manual J calculation depends on did not exist in one place — verified, consistent, and ready to use. Builders were guessing. HVAC contractors were guessing. And homeowners were writing $400, $600, $800 utility checks every month because of it.

90 to 95 percent of every wall assembly being built or proposed in North America today is already in this library. Verified. Calculated. Ready to drop into your Manual J the same day.

No hiring a third party. No waiting. No guessing.

WHAT’S INSIDE:

• 700+ verified wall assemblies — 2x4, 2x6, 2x8, Tstud, metal stud, and more

• 60 insulation manufacturers covered

• Whole-wall R-values, U-factors, Canadian Metric and EU RSI values

• Parallel-path and whole-wall calculations — so you know what the label says vs. what the wall actually does

• Layer-by-layer breakdowns — every component, every calculation shown

• All 8 North American climate zones

• Material reference tables — air films, lumber, OSB, plywood, cladding, ZIP-R, rigid, semi-rigid, and integrated systems

• Fixed reference assemblies for direct apples-to-apples comparison

• Performance-path compliance support — Passive House, LEED, CSA Step Code, Net Zero

• Video walkthrough — exactly how to read, compare, and apply every assembly

• Free lifetime updates — SIPs, TSUPS, ICF, and emerging assembly types added as they are verified

This is not a code checklist. This is not the minimum. This is the physics behind every wall decision you will ever make.

And Here’s What Comes With It — Free.

Every purchase includes four additional resources at no extra cost:

• The Complete Envelope Playbook & Checklist (~105 pages) — $99 value, yours free. The step-by-step execution framework for new builds, retrofits, and remodels.

• Thermal Suite Deconstruction — A complete breakdown of how a real home achieved a 50% BTU reduction. Real R-values, real U-values, real results. Not a simulation. Copy what already works.

• Retrofit & Remodeling Guide (~100 pages) — Two real case studies: a mold-crippled home restored to health, and a 3,000 sq ft house paying $800/month in utilities transformed by targeted envelope upgrades.

• Carbonless: An Introduction to Sustainable Building — The foundational ebook. Free. Because you should understand the physics before you apply the numbers.

One Number. One Purchase. One Decision That Changes Every Project After This.

Personal Library Member — $299 one time
One individual user. All downloads. All bonuses. Free lifetime updates.

Corporate Library Member — $2,000 one time
One company. Up to 10 users. Everything in the personal license.

Need more than 10 users? Contact hello@carbonless.org

Every day a builder breaks ground without this number, a client moves into a home that will underperform for the next 100 years.

The walls go up. The HVAC gets sized. The mistake gets sealed inside.

This library exists so that never has to happen on your job site again.

— Brian Iverson
Founder, Carbonless Inc.
Certified Energy Auditor
Return on Efficiency™