1. 1Create account
2. 2Pay $7
3. 3Build your C3

The C3 worksheet, on the web.

Type in your house details to calculate WSEC-R energy credits. One-time payment per project. Use it on Mac, mobile, or PC.

Why it's better than the WSU spreadsheet

• Mac, mobile, or PC — open it anywhere
• Saves your work to your account, not your hard drive
• Plain-English explanations on every credit option
• Permit-ready PDF output in wsec.ai's format
• Reads from the WAC directly, not the published code book