Building Codes to Support Electric Vehicle Charging

Access to charging infrastructure is important for more widespread adoption of electric vehicles. Most daily travel is well within the range of a typical electric vehicle, but it is important for vehicle purchasers to be comfortable that they can make longer trips. Evidence to date suggests that most charging will take place at home, with workplace charging the next largest slice of the pie.

Building codes can facilitate access to charging by ensuring that parking areas are pre-wired during initial construction (when it is cheap and easy to do), that charging is available in new multifamily housing, and be ensuring that EV charging is included in large commercial developments. A number of jurisdictions have begun to adopt building codes that mandate either pre-wiring for EV charging, or mandate that a certain number of spaces in new parking facilities are wired for charging.

It is cheaper to wire parking areas during initial construction

Establishing capacity for charging during construction costs much less than retrofitting, as retrofitting often requires retrenching, rewiring or upgrades to electric panels. For commercial installations, retrofitting can add thousands of dollars to the cost of a charging station installation.   For residential single-family homes the cost of retrofitting for Level 2 charging is at least several hundred dollars more than preparing that home during new construction.

Proposed Code Concept:

For new single family residential construction

Require a 240 volt circuit or upgraded wiring or conduit for future installation in the garage or parking area

For new multi-family construction

Require conduit from the service panel to the parking area, with pre-wiring to allow charging to be installed in the future in at least 5% of parking spaces

Commercial construction

Require conduit from the service panel to the parking area, with pre-wiring to allow charging to be installed in the future in at least 5% of parking spaces; for large parking areas require that there be some minimum number of actual charging units installed. For employee parking, this could be very inexpensive level 1 charging.