Permitting & Codes · Engineering Glossary

Certificate of Occupancy (CO)

A Certificate of Occupancy (CO) is a document issued by the local building department confirming that a building has been constructed or altered in compliance with the approved plans and applicable codes, and that it is safe for its intended occupancy. A CO is required before a building can legally be occupied.

What Engineers Mean by Certificate of Occupancy (CO)

To obtain a CO, the building must pass all required inspections — structural framing, rough MEP, energy, fire, and final. Any items found deficient during inspection (correction items) must be remedied before the CO is issued. For tenant improvements, a CO (or sometimes a Certificate of Final Inspection) is issued for the specific space. Temporary COs can be issued for portions of a building while other areas remain under construction. Apex Grid's engineers respond to plan-check corrections and support the inspection process to help clients reach CO as efficiently as possible.

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Apex Grid Engineering maintains this glossary as a resource for architects, contractors, developers, and property owners who encounter unfamiliar engineering terminology on their projects.

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