ADU
Accessory dwelling unit: a separate dwelling on the same property as another residence.
In your project: Ask which site, utility and permit requirements apply to this particular parcel.
01 / Understand the conversation
Construction & electrical glossary
Translate the words in your plans, proposals and inspection notes into decisions you can make. Search by a term, abbreviation or topic.
Find a term. Know what to ask.
Definitions are written for planning conversations. Use the code library for the adopted requirements governing your installation.
40 terms
AHJ
Authority having jurisdiction: the agency or official responsible for enforcing a requirement.
In your project: The building department, fire authority and utility may each review different parts of one project.
Allowance
A stated amount carried in a proposal for an item whose final selection or scope is still open.
In your project: Ask what quantity, quality, labor and tax the allowance includes and how an overrun is approved.
Amperes (A)
A measure of electric current flowing through a circuit.
In your project: An appliance operating current, a circuit breaker rating and a service rating describe different things.
As-built record
A record showing the installation as it was actually constructed.
In your project: Ask for updated circuit labels, equipment locations and approved revisions at handover.
Branch circuit
The part of an electrical system serving outlets or equipment after its final overcurrent protection.
In your project: Adding equipment can require a new circuit even when the panel has spare physical spaces.
CALGreen
California’s Green Building Standards Code, Title 24 Part 11.
In your project: It is separate from the Energy Code and includes mandatory measures; voluntary tiers may be locally adopted.
Change order
A written change to the contracted scope, price or schedule.
In your project: Confirm the changed work and its cost before it begins; CSLB explains the required written agreement.
Circuit breaker
A protective device designed to interrupt certain abnormal current conditions.
In your project: The number on the breaker is not a measurement of how much electricity the equipment normally uses.
Commissioning
A documented process for checking that installed systems operate as intended.
In your project: For controls or automation, ask which functions will be demonstrated and recorded.
Connected load
The combined stated electrical input of the equipment listed in a calculation.
In your project: It does not automatically equal a code-calculated service load or the building’s actual peak demand.
Contingency
Money reserved in the owner’s budget for defined uncertainties.
In your project: Keep it separate from the quoted contract price and identify what would release the reserve.
Dedicated circuit
A circuit serving a particular appliance or equipment load.
In your project: Confirm its voltage, protection and wiring against the equipment instructions and approved design.
Demand
The power being used at a particular time or over a specified measurement interval.
In your project: A monthly energy total cannot by itself tell you the home’s peak electrical demand.
Easement
A right affecting how part of a property may be used or accessed by another party.
In your project: Check the recorded documents before locating new structures, service equipment or trenching.
Encroachment permit
Authorization for work affecting a public right of way, such as a sidewalk or street.
In your project: A building permit may not cover the utility trench or driveway work outside the property line.
Energy management system
Controls that monitor or manage electrical loads under a defined operating strategy.
In your project: Ask what is controlled, how failures are handled and whether the proposed system is accepted for this installation.
EVSE
Electric vehicle supply equipment: the equipment that safely supplies electricity to an EV.
In your project: For AC charging, the vehicle’s onboard charger also limits charging power.
Feeder
Conductors supplying a downstream distribution point, such as a subpanel.
In your project: Available capacity depends on the upstream equipment and feeder design, not only the subpanel label.
Final inspection
An inspection near completion to check the permitted work and required closeout items.
In your project: Confirm that the permit is actually closed and that any separate utility or occupancy approval is complete.
GFCI
Ground-fault circuit interrupter: protection intended to reduce shock risk from certain ground faults.
In your project: A GFCI device does not establish that all wiring and grounding conditions are correct.
Grounding and bonding
Related safety functions that connect specified system parts and provide paths for fault current.
In your project: They are not interchangeable terms; their design depends on the system and equipment.
Hardwired
Equipment connected directly to fixed wiring instead of through a plug and receptacle.
In your project: Compare the manufacturer’s installation instructions and any required disconnecting means.
Kilowatt (kW)
1,000 watts: a unit of electrical power.
In your project: Use kW when comparing how much power equipment draws while operating.
Kilowatt-hour (kWh)
Energy equal to one kilowatt used for one hour.
In your project: Use kWh for energy consumption and usage charges, not for sizing a circuit breaker.
Load calculation
A calculation using an applicable code method to determine design load.
In your project: It can include demand factors and other rules; adding breaker handles is not that method.
Load management
A strategy that limits or coordinates loads under specified conditions.
In your project: A user-set charging schedule is different from approved equipment that enforces a load limit.
Nameplate
The equipment label containing ratings and identification provided by its manufacturer.
In your project: Photograph accessible labels; do not remove electrical covers to look for one.
Panel schedule
A directory or drawing identifying the circuits connected to a panel.
In your project: Labels should describe what a circuit actually serves and be checked after alterations.
Plan check
Review of submitted drawings and documents by the applicable reviewing agencies.
In your project: A review comment is a request for a response or revision, not permission to begin work.
Punch list
A list of remaining completion or correction items identified near project handover.
In your project: Record who will handle each item and what evidence will show it is closed.
Reach code
A local requirement that goes beyond a state minimum in a defined area.
In your project: Check the current adopted ordinance and enforcement guidance for the project’s jurisdiction.
Rough inspection
An inspection of work before it is covered by finishes or otherwise concealed.
In your project: Coordinate the inspection before insulation, drywall or other covering work.
Scope of work
The description of what a project includes and the boundaries of the contractor’s work.
In your project: Compare scope and exclusions before comparing proposal totals.
Service upgrade
A change to the electrical supply arrangement or capacity serving the property.
In your project: A panel replacement and a utility service upgrade are not automatically the same scope.
Single-line diagram
A simplified drawing showing the electrical system’s main connections and ratings.
In your project: It helps communicate the service, feeders, panels and major equipment during review.
Subpanel
A downstream panel supplied from another distribution point.
In your project: Adding one can create circuit spaces without increasing the capacity of the utility service.
Title 24
The California Building Standards Code, organized into multiple parts.
In your project: When someone says “Title 24,” ask whether they mean energy compliance or the broader code family.
Voltage (V)
Electrical potential difference between points in a system.
In your project: Equipment must match the actual supply; 120 V, 208 V and 240 V are not interchangeable.
Watt (W)
A unit of power; 1,000 W equals 1 kW.
In your project: Use the electrical input rating rather than a heater’s output capacity in BTU/h.
No matching terms. Try a shorter word or choose all topics.
Three distinctions worth keeping.
Spaces vs. capacity
A spare position in a panel tells you there may be physical room for a breaker. It does not establish the service, feeder or panel’s capacity for a new load.
Power vs. energy
A 1 kW load operating for 2 hours uses 2 kWh. Power describes the rate; energy adds time.
Read the EIA explanation →Estimate vs. contract change
Track unresolved scope in the estimate. Once contracted, document changes in writing before the changed work begins.
Read CSLB’s contract guidance →Code terminology reference: CBSC guidebooks, including the 2025 Guide to Title 24.
FROM THE YKCA JOURNAL
Make this page useful for your project.
How should I use a glossary definition while comparing quotes?
Search the term, read its practical question and apply that question to the exact proposal line. Keep the written answer with the quote; a definition alone does not establish what the contractor included.
