Permit glossary

Permit and construction-code terminology defined in plain English — AHJ, plan review, Title 24, IECC, occupancy classes, setbacks, and more.

AHJ (Authority Having Jurisdiction)
The local agency that interprets and enforces building codes for your project.
Plan review
The technical review of submitted drawings and calculations against adopted codes before a permit is issued.
Correction letter
A list of plan-review comments that must be resolved before approval.
Counter permit
An over-the-counter, same-day permit issued for simple, low-risk work.
Title 24
California's energy efficiency standards, required for most residential and commercial projects in CA.
IECC
International Energy Conservation Code — the model code most U.S. states adopt for building energy efficiency.
IRC / IBC
International Residential Code and International Building Code — the model construction codes most U.S. jurisdictions adopt.
NEC
The National Electrical Code, governing electrical installations in the U.S.
IMC / UMC
International and Uniform Mechanical Codes for HVAC and gas systems.
UPC / IPC
Uniform and International Plumbing Codes.
Egress
The path of travel from any point in a building to a public way — heavily regulated for life-safety.
Occupancy classification
The category (A, B, E, F, H, I, M, R, S, U) that determines code requirements for a building's intended use.
Setback
The minimum distance a structure must be from property lines or other features.
Variance
A discretionary approval that waives a zoning rule for a specific property.
Certificate of Occupancy (CO)
Final document confirming a building or tenant space is legal to occupy.
Tenant Improvement (TI)
Build-out work inside an existing commercial shell.
Change of use
A permit triggered when an existing space switches to a different occupancy classification.
Rapid shutdown
An NEC requirement to de-energize rooftop solar conductors during emergencies.
Manual J / D / S
ACCA HVAC sizing methodologies (load, ductwork, equipment) required by most jurisdictions.
Stormwater (SWPPP)
A pollution-prevention plan required for many construction sites that disturb soil.