Building Permit Glossary
Impervious Surface
Surface that prevents water infiltration, such as roofs, asphalt, or concrete.
Core permitting
Applies to
Most residential permits
Project example
On a residential project, this term belongs in the scope, plan set, permit application, or inspection conversation when the local AHJ uses it.
Also called
impervious areahardscape
Where this term shows up in permit work and how it affects the project
Confirm the local definition and measurement before filing. The term can change the documents, review sequence, inspection readiness, or customer expectation for the project.
If this term appears in a form, plan comment, or local ordinance, start with the building permit guide, compare it against the zoning permit guide, then use the permit guide directory to find the right local path.