Permitting & Codes · Engineering Glossary
The International Energy Conservation Code (IECC) is the model energy code published by the ICC that establishes minimum efficiency requirements for the building envelope, HVAC systems, lighting, and water heating in commercial and residential construction. Most states adopt the IECC or their own equivalent, such as California's Title 24.
The IECC is updated on the same three-year cycle as the IBC and is adopted independently by each state — meaning a 2021 IBC state might still enforce IECC 2018. Commercial buildings must meet Chapter 5 (commercial energy efficiency) of the IECC, which sets prescriptive or performance-based requirements for insulation, fenestration, HVAC equipment efficiency, and lighting power density. Energy compliance often requires calculation documentation — COMcheck for prescriptive compliance, or whole-building energy modeling for performance paths. Apex Grid's engineers produce the required energy compliance submittals as part of MEP and energy-code engagements.
Apex Grid Engineering maintains this glossary as a resource for architects, contractors, developers, and property owners who encounter unfamiliar engineering terminology on their projects.
View All Engineering TermsApex Grid's licensed PEs provide permitting & codes services across multiple jurisdictions — with fast quote turnaround and permit-ready documents.
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