What an Apartment Building Electrical Capacity Assessment Should Check

A capacity assessment answers a building-specific question: what charging equipment and resident service can the electrical system support, under which assumptions, and what changes would be needed? The answer cannot be read from an EV charger’s nameplate, the number of empty breaker spaces, or a nearby utility map. A qualified electrical professional must assess the property and apply the rules for its location.

Start with the decision the building needs to make

Before commissioning a study, agree on the question it should answer. A resident request for one assigned stall has a different scope from a board planning shared charging for a garage. Ask whether the decision is about current installation feasibility, future capacity, an upgrade, or the level of charging the building can reliably promise.

The intended service matters. Record how many residents may charge now and later, how long cars are usually parked, and whether the building needs to support charging overnight, through the day, or in shorter visits. These are planning inputs, not a way for residents to calculate electrical capacity.

Gather a decision-ready information packet

Area	Useful information to collect	Why it matters
Building supply	Existing electrical drawings, service and transformer records, panel and subpanel locations, voltage or phase information if documented, and known upgrades	The professional needs to understand how power reaches the building and where charging could connect.
Existing demand	Available utility bills or interval data, peak-demand records if available, major electric equipment, and planned changes such as heat pumps	EV charging competes with current and future building loads. Consumption history helps describe use but does not, by itself, prove spare capacity.
Parking and route	Stall map, assigned and shared spaces, proposed charger locations, indoor or outdoor areas, route distance, and physical constraints	Cable routes, parking use, and accessible access affect both feasibility and layout.
Charging need	Resident interest, likely vehicle use, charging frequency, typical dwell time, and the minimum useful service for residents	A design should respond to how the building will be used, not just the maximum rating printed on equipment.
Ownership and meters	Which account serves the proposed equipment, who controls the electrical room, and how charging energy is currently measured	Metering and account arrangements affect data access and later operating choices.
Utility and approvals	Serving utility, known connection limits, building approvals, and the local permit or inspection authority	A building assessment and a utility connection review answer related but different questions.

Do not open electrical panels or take measurements yourself. Ask the building manager, electrician, utility, or existing project files for the records. The Ontario Electrical Safety Authority’s multi-residential checklist, for example, asks about current and future demand, utility involvement, parking arrangement, residents’ expectations, and maintenance planning. It is an Ontario planning aid, not a universal capacity formula.

In B.C., BC Hydro says it can provide up to 12 months of meter-usage data to support an electrician’s load calculation. Availability and authorization depend on the account, so confirm the current utility process. This is one local example of useful load history, not a substitute for the calculation.

Ask what the assessment will deliver

Agree on the study boundary before work begins. A useful result should state which electrical equipment and parking areas were examined, which records and assumptions were used, and what remains unknown. Ask the professional to explain the present load picture, relevant utility or transformer constraints, and the additional information needed before design or connection approval.

The report should compare practical paths where appropriate: a service or panel upgrade, lower-power charging, sharing available capacity, managed charging, or a phased project. It should identify the trade-offs and next approvals without implying that one path will work at every property.

Panel space is not a capacity result

An empty breaker position may be useful information, but it does not establish that the service, transformer, feeder, or building system can supply a new load. Likewise, historic energy use alone does not settle the question. Capacity depends on the connected system, how other loads operate, the proposed equipment, applicable requirements, and the building’s expected future demand.

Move from assessment to the next decision

If the professional identifies a feasible option, use the findings to guide equipment selection, utility coordination, and the installation design. If capacity is constrained, compare an upgrade with managed charging and plan the whole shared garage before committing to a charger count. The installation guide covers delivery steps; local permits and building approval belong in the permissions guide.

Briefing checklist

• State the decision and the parking areas in scope.
• Gather electrical records, utility data, and known future building loads.
• Map stalls, likely routes, and current and expected resident demand.
• Identify the utility account and meter arrangement.
• Ask what the assessment will and will not establish.
• Confirm the professional, utility, permit, and approval steps before work.

This checklist prepares a conversation. It is not a load calculation, code check, or authorization to install equipment.