09/08/2026
Building codes are updated roughly every three years. And when they are, municipalities often layer on their own interpretations — which means the local version of a code can differ meaningfully from the state version.
We recently worked through exactly this on a home addition. The Illinois State Plumbing Code and the local municipality's code each had their own matrix for water service requirements. We ran the numbers on both, carefully and methodically, and confirmed that no new water service line would be required.
It wasn't complicated math. It was disciplined process. That's usually where surprises get caught before they become expensive problems.