EV charging design

EV charging design works out how many chargers a building can support, how to connect them without an expensive service upgrade where possible, and how to lay out the wiring so more chargers can be added later. We design charging for commercial parkades, workplaces, condominiums and rental buildings, and fleet depots, from a few stalls to a whole parkade.

The question we hear most often is "how many chargers can we put in?" The honest answer is that it depends less on the chargers than on the building: how much spare capacity the electrical service has, where the panels are relative to the parking, how the stalls are owned and who pays for the power. A small amount of design work up front prevents the most common mistake, which is installing a few chargers in a way that makes the next twenty much more expensive.

What we design and build

Capacity assessments of the existing service and distribution, using measured demand where available.
Charger selection by type and power: Level 2 for most parking, DC fast charging for fleets and short-stay sites.
Load management systems that share available capacity among many chargers.
Panels, feeders, transformers and conduit routes in parkades and surface lots.
Metering and billing arrangements for condos, rental buildings and shared workplaces.
Phased plans that make stalls EV-ready now and add chargers as demand grows.
Coordination with the utility when a service upgrade or new service is needed.

Sharing capacity with load management

Most cars parked overnight or for a work shift need far less energy than a charger can deliver at full power. Load management uses that fact. A controller watches the total demand and divides the available capacity among the cars that are plugged in, slowing or pausing some when the building's load is high. The electrical code allows a properly designed energy management system to limit the load counted in the design, which can let one feeder serve many more chargers than it could at full rating. The conditions are specific, so check the current edition of the code and your province's rules for your project.

Load management shares a fixed supply. The load manager reads the building's total demand and tells each charger how much power it may draw. When capacity is available every car charges at full rate; when it is tight, some chargers slow down or wait their turn.

How it works

Brief. We start by asking why: tenant or resident requests, a fleet conversion, a municipal requirement, or a plan to make every stall EV-ready. We find out how many stalls, who uses them, how long cars are parked and who will pay for the energy.
Capacity check. We review the service, the distribution and twelve months of demand data, and survey electrical rooms and the parking area for panel space and conduit routes.
Options. We compare approaches, such as a few full-power chargers, many managed chargers, or EV-ready stalls with chargers added later, and set out the electrical work each one needs.
Design. We prepare layouts, the single-line diagram, panel schedules, load calculations and specifications for chargers and load management. Drawings for permit are sealed by a licensed professional engineer where required.
Construction and handover. Installation is done by licensed electrical contractors under permit. We review submittals, visit site, and check that the load management settings match the design before chargers go into service.

What to have ready

A parking plan showing stalls, ownership or assignment, and electrical rooms.
Twelve months of utility bills or interval data.
Existing single-line diagram and panel schedules.
Your goals: number of chargers now, number later, and how users will be billed.
For condos, any board or owner approvals already in place.

What you get

A clear answer on how many chargers the building can support with and without load management, and what each option costs in electrical work. Drawings and specifications ready for permit and tender, including a layout that reserves conduit routes and panel space for future stalls. A written description of how the load management works and what settings it uses. Where a service upgrade is needed, the information the utility will ask for. For phased projects, a roadmap that shows what is built in each phase and what triggers the next one, so future boards or managers can follow the plan.

A typical case

A 120-unit condominium has a parkade with one stall per unit and a growing list of owners asking for chargers. The service has modest spare capacity at peak. Installing full-power chargers for the first dozen owners would use it all. Instead, the design adds a dedicated EV panel fed from the spare capacity, runs conduit along each parking row, and uses managed Level 2 chargers so that the same feeder can serve every stall over time. Owners who want a charger have one added to their stall on the existing infrastructure, and individual metering lets the corporation bill each owner for their own energy.

Backbone first, chargers over time. A dedicated EV panel feeds conduit along each parking row, with a short stub to every stall. Chargers are added to stalls as owners ask for them, on the same infrastructure, instead of a new circuit from the nearest panel each time.

Mistakes to avoid

Connecting the first few chargers to whatever panel is closest, using up spare capacity the rest of the parkade will need.
Running separate small conduits stall by stall instead of planning a backbone along each row.
Choosing chargers before deciding how users will be billed, then finding they cannot report energy per user.
Forgetting that chargers in parkades and outdoor lots need protection from vehicles, water and road salt.

Who it's for

Condominium boards and property managers responding to owner requests.
Owners of rental and commercial buildings adding chargers for tenants and visitors.
Employers offering workplace charging.
Fleet operators converting vans, trucks or buses.
Developers designing new parkades to municipal EV-ready requirements.

For more detail, read EV charging levels explained, EV load management, EV charging in condos and multi-unit buildings and electrical load calculations.

Common questions

Do we need a service upgrade?

Not always. Many buildings have enough spare capacity for a useful number of managed chargers. The capacity check answers this before you commit to anything.

Are there requirements for new buildings?

Some municipalities, particularly in British Columbia, require new residential parking to be EV-ready. Rules vary by municipality and are changing, so check with your local authority early in design.

Will slower managed charging be enough?

For cars parked overnight or for a work shift, usually yes. Most daily driving needs a modest amount of energy. Sites with short visits or fleets with tight schedules may need some faster chargers.