No published ratio decides this for you. A new apartment building’s charger count is a planning decision built from three numbers the developer sets on paper: how many bays get a working charger at opening, how many more are prepared so a charger can be added without new groundworks, and how much electrical capacity is reserved behind both. Adoption assumptions move the numbers — the structure does not change.
Key Takeaways
- The count is three numbers: chargers fitted at opening, bays prepared for later, and capacity reserved behind both.
- Adoption is the developer’s stated assumption — the worked example’s figures are invented, and yours should be written down the same way.
- Preparation during construction is the cheap direction; fit chargers in phases as session records replace assumptions.
- Any code floor for the project comes from its own permit set, never from a universal ratio.
The Three Numbers Behind the Count
| Decision | What it sets | Where the number comes from |
|---|---|---|
| Chargers fitted at opening | Working bays residents can use on day one | The developer’s own estimate of EV households at opening — a market assumption, stated as one |
| Bays prepared for later | Spaces that can gain a charger as a fitting job, not a building job | How far ahead the project plans: preparation is conduit, routes and panel space reserved during construction |
| Capacity reserved | How many chargers can ever run at once | The project’s load study; charging is a continuous load, sized at 125% of charger current under the NEC |
Worked example — every figure invented for illustration. Take a 60-unit building. The developer assumes 6 households arrive with an EV and adoption roughly doubles over five years. A coherent paper answer: fit 6 charging bays at opening as a shared pool, prepare 12 more bays with routes and panel space, and reserve capacity for all 18. If the opening assumption were 15 EV households instead, the fitted number rises and the prepared number falls — same structure, different assumption. Prices scale the same way: DOE-cited figures put public Level 2 at about $3,500 equipment plus $2,500 installation per connector in the U.S., while a prepared bay carries neither cost until the charger is fitted.
Phase the Fit, Not the Infrastructure
- Fit for counted early demand. Chargers fitted ahead of residents are capital standing idle; chargers fitted behind demand are a queue and a complaint.
- Prepare generously. Cable routes, conduit and spare panel capacity are cheap while walls are open and expensive forever after — this is the asymmetry that should drive the prepared-bays number up.
- Let records release each phase. Once the building is occupied, session data — which bays fill, on which nights — replaces the opening assumption when the next phase is argued.
- Check the project’s own code position. Some projects also carry a preparation or installation duty from the local code or planning approval; that floor, where it exists, comes from the project’s permit set — not from a general rule.
The developer-side clauses that turn these numbers into a specification are covered in our overview of EV-ready new construction and building codes, and the capacity side in our guide to building load calculation basics.
Hardware That Fits a Phased Count
Dual-connector hardware suits a phased plan because each unit adds two bays at once: the EV-AC03201T provides two Type 2 connectors sharing up to 43 kW (22 kW per connector), with RFID access and OCPP 1.6J so usage is recorded per resident — the records that justify the next phase. Its touchscreen is a display, not a payment terminal. For one wallbox per prepared bay, the EV-ACT3204PE is a 22 kW three-phase Type 2 wallbox with RFID and app control, IP66, CE. EVDANCE is a Shenzhen manufacturer founded in 2011, exports to 30+ countries, and offers private label from 100 units under its OEM program, with a 3-year standard warranty.
Frequently Asked Questions
Is there a standard chargers-per-unit ratio for new buildings?
No — no standard or regulator publishes one that applies across markets, and any ratio quoted without the project’s own assumptions is a sales rule of thumb. Some local codes set preparation duties for specific projects; that is a floor read from the permit set, not a planning ratio.
Should every space get a charger at opening?
Almost never on day one. Fit chargers for the EV households you actually expect at opening, prepare more bays so fitting later is cheap, and reserve the capacity behind the full plan.
Assigned or shared bays in a new building?
The sales model decides. Shared bays spread fewer chargers across more residents and need access rules; assigned bays simplify attribution but tie each charger to one household. The choice changes the fitted count, so it belongs in the same paper decision.
Related Reading
- EV-Ready New Construction: 2026 Building Codes and the Real Cost of Waiting
- Adding EV Chargers to a Building: Load Calculation Basics
- Apartment and Condo EV Charging: Solutions for Shared Parking
