Your permit-ready Washington energy code package.
Built directly on the 2021 WSEC-R text in the Washington Administrative Code — credit math, compliance certificate, and the documentation your building department expects.
Or see a sample compliance package →What you hand the building department
Every input, every calculation step, and the WAC citation behind each credit — with a QR code your reviewer can use to verify the math independently.
Download the full sample PDF →Pricing
Tools you use yourself, or a real human to do it with you.
Tools — Do it yourself
Type in your house details and calculate your energy credits. Use it on Mac, mobile, or PC.
- Web-based — no install
- Account required to save
- Permit-ready PDF output
Upload your plans after payment. AI reads the plans; you confirm the inputs and build your compliance package.
- Guided wizard with live credit math
- AI chat for code questions
- Final compliance PDF
- Plan-set checklist
- Blower door + insulation + air leakage stickers
- Build Plan with subcontractor homework
One-time · no subscription
Help — Get a human in the loop
Travis Smith reviews your plans and works through the credit selections with you.
Plan review, credit selections, and your compliance package.
See details →Room-by-room heating and cooling loads. Base price covers up to 3,000 conditioned sq ft.
See details →Credit selections, compliance package, and Manual J for up to 3,000 conditioned sq ft.
See details →Your $25 wizard payment is credited toward the $149 review or $349 bundle on the same project, not standalone Manual J.
We review your plans and work through the credit selections with you until they match what you're actually building. If the building department sends back a correction on our work, we fix it at no charge. Design changes after delivery are quoted separately.
Built for how Washington actually builds
Mac, mobile, or PC.
Open it anywhere. No macros, no antivirus blocks, no Windows-only install.
Real-time math.
Pick credits, watch your status update. No clicking through tabs to figure out why your sheet won't total.
Plain-English explanations.
Every credit option includes the WAC citation and what it actually means in build terms.
Frequently asked questions
How much does WSEC compliance cost?
The 2021 WSEC-R itself is free to download from the Washington State Building Code Council. The compliance work — running the C3 worksheet, generating certificates, getting a HERS rating if you use the ERI path — is what costs time and money. On wsec.ai, the calculator is $7, a full compliance package is $25, and human help starts at $149. A HERS-only path typically runs several hundred dollars more for a project that could have landed its credits prescriptively.
Do I need a HERS rater for the prescriptive path?
No. The prescriptive path — R402 envelope requirements plus R406 energy credits — and the Total UA alternative are self-documented; no HERS rater or energy modeler needed. Washington's performance path (R405, Total Building Performance) does require whole-building energy modeling software, usually run by a modeler. The 2021 WSEC-R has no separate ERI or HERS-score compliance path — its alternatives are R405 performance and R407 Certified Passive House. wsec.ai handles the prescriptive and Total UA paths.
What is the WSU C3 calculator and is wsec.ai related to it?
The WSU C3 calculator is a macro-enabled Excel workbook published by the Washington State University Energy Program. wsec.ai is independent of WSU. Our calculator implements credit logic from the Washington Administrative Code directly — we do not reproduce or rely on WSU's C3 spreadsheet. wsec.ai is not endorsed by, affiliated with, or approved by WSU or the Washington State Building Code Council.
What does it mean that the engine is "audited against the WAC"?
Energy code compliance ultimately rests on the Washington Administrative Code (WAC) — the legal source of the 2021 WSEC-R. The published 2021 WSEC-R book and the WSU C3 spreadsheet are widely used reference tools, but both contain known minor deviations from the WAC. wsec.ai's compliance engine reads from the WAC directly. R406 credit values were certified line-by-line against WAC 51-11R-40610, 40620, and 40621, and the engine is re-audited as it changes — most recently a black-box run of roughly 110 cases across classification tiers, renewable boundaries, credit stacking, and footnote scope, which found no compliance-math defects. Discrepancies found in earlier audits are published on our receipts page and locked with regression tests. Re-audit triggers on any WAC amendment.
Is wsec.ai approved by Washington State?
No. The 2021 WSEC-R does not have a state approval process for compliance software. Building officials accept whatever documentation demonstrates compliance — the WSU C3 worksheet, hand calculations, or third-party tools. wsec.ai is designed to produce the same outputs your jurisdiction already accepts, and the engine is audited line-by-line against the WAC text on an ongoing basis. Final authority always rests with your building official.
Does wsec.ai work for the Seattle Energy Code?
Partially. The Seattle Energy Code (SEC) amends the WSEC-R with stricter requirements. wsec.ai's prescriptive path covers WSEC-R baseline; Seattle-specific amendments are covered in our Seattle Energy Code guide.