About CodeCheck

CodeCheck is built by a practicing HVAC/plumbing engineer who got tired of digging through state agency sites, rule registers and PDF supplements before every project in a new jurisdiction.

The goal is simple: for every US state, show which mechanical, plumbing, fuel gas and energy code editions are in force, when they took effect, how A2L refrigerants are handled, and which local amendments matter. Each value links to its source.

How the data works

• Each value comes from an official source: a state agency page, the state's administrative code or register, or the U.S. DOE Building Energy Codes Program.
• Each record shows a source link and a last-checked date.
• If we can't confirm a value, it's labeled unverified rather than guessed.
• Sponsors never influence the data.

CodeCheck is a reference, not legal or engineering advice. The authority having jurisdiction has the final word.

Found something out of date?

Corrections from engineers, contractors and code officials are welcome. (A correction form is coming soon.)