An EV charging installation reaches the drawings twice: on the architect’s set as space, bays and protection, and on the M&E set as supply, load and circuits. Neither set works alone — a bay drawn without capacity is a promise the building cannot keep, and capacity reserved without bays is money buried. The two sets meet in a short list of coordination questions that should be answered before either one is frozen.
Key Takeaways
- The architect’s set carries space, bays and protection; the M&E set carries supply, load and circuits — neither is complete alone.
- One load figure, from the project’s own study, appears on both sets; charging loads are continuous, sized at 125% under the NEC.
- Clearances and siting values come from the project’s code review, never from a guide.
- The schedule names the exact model and variant, including its connector — confirmed in writing, not assumed.
Two Drawing Sets, One Installation
| Item | The architect’s set shows | The M&E set shows |
|---|---|---|
| Bay layout | Which bays charge, signage and bay marking, the route a driver walks | Which bays are wired in this phase, and the containment route to each |
| Charger position | Position, mounting form and the clear space around each unit, as the project’s code review sets it | The circuit each position is fed from |
| Electrical capacity | The space reserved for switchgear and for future expansion | The load schedule: charger currents as continuous loads at 125% under the NEC, summed against panel capacity |
| Connector decision | The bay furniture the chosen connector implies — holsters, protection, signage | The exact models and variants the circuits are sized for |
| Access and metering hardware | Where readers, screens and signs sit on the bay | The power and data runs the access and platform hardware needs |
| Future phases | Bays drawn as future charging, with the routes kept clear | Spare ways and reserved capacity, stated on the schedule |
Two disciplines keep the sets honest. First, values that look like dimensions — clearances, mounting positions, protection details — come from the project’s own code review and the authority’s current text; no article can set them for a real building. Second, the load figure appears once: the same number, from the project’s load study, on both sets. Our walkthrough of building load calculation basics shows how that figure is built.
The Coordination Questions
- Who owns the load figure? One engineer, one study, one number — both sets cite it, neither invents its own.
- When does the connector decision freeze? Bay furniture and circuit sizing both depend on it; a late change redraws two sets, not one.
- Where does the platform hardware live? Access and billing are platform decisions; the drawings only give them space, power and data runs.
- What is handed over? Certificates, manuals and test records naming the exact models installed, listed as a deliverable on the M&E set.
Hardware Notes for the Drawing Stage
Write models onto the schedule as their listings state them. The EV-RHDC30K-L is a compact DC unit at 22 kW — below the U.S. DOT’s 50–350 kW fast-charging band — with OCPP 1.6J and IP54; its connector variant is a written confirmation from the supplier, never a drawing assumption. Wallboxes come in configurations: the EV-ACT3204PE is a 22 kW three-phase Type 2 unit in tethered-cable version, and the schedule must name which one the circuits serve. EVDANCE is a Shenzhen manufacturer founded in 2011, with a 3-year standard warranty. Drawing-stage enquiries go through our commercial charging team or contact us, naming the project and the drawing stage.
Frequently Asked Questions
Do architects choose the charger model?
The architect’s set fixes space and position. Model and variant selection is a project decision taken with the M&E engineer, because circuits are sized to the exact unit — its current, its phases, its configuration.
What load figure should the M&E set carry?
The figure from the project’s own load study, with each charger treated as a continuous load — breaker at 125% of charger current under the NEC, so 40 A of charging takes a 50 A breaker. Never a figure copied from another project.
Can a compact DC charger be drawn into a basement car park?
The class exists, at about 20–30 kW. But the siting questions — ventilation, structure, fire strategy — belong to the project’s own code review and the local authority. A drawing set records their answers; an article cannot provide them.
Related Reading
- Adding EV Chargers to a Building: Load Calculation Basics
- How to Plan a Workplace EV Charging Program
- How Much Does It Cost to Install a Commercial EV Charging Station?
- EV Charger Certifications Explained: CE, UKCA, UL, ETL, CB and What Buyers Should Ask For
