The transportation sector contributes more than a quarter (28 percent) of the overall greenhouse gas (GHG) emissions in the United States.
As governments across the country implement plans to decarbonize the transportation sector, many are focusing on transitioning from the internal combustion engine (ICE) to electric vehicles (EVs) to achieve their goals (e.g., Denver). EVs are projected to reach cost parity with ICE vehicles by 2025; therefore, there will be growing demand for EV charging options.
A key factor for individuals considering the purchase of an EV is whether they have sufficient access to vehicle charging options. Since 80 percent of current EV owners report charging their vehicles at home, and approximately 50 percent of all vehicles in the United States are located in multi-unit dwellings (MUD), it is important to consider EV charging access in MUDs. Residents of MUDs typically have limited, if any, ability to modify their buildings to install EV charging apparatus, or EV supply equipment (EVSE).
Governments can play a critical role in supporting the expansion of EVs through building codes and ordinances but there are several important questions they will need to address.
Why are building codes important for EVs?
Building energy codes establish the standards for constructing commercial and residential buildings. According to the U.S. Department of Energy, the implementation of energy codes is projected to save a cumulative $126 billion in energy savings and 841 MMT of avoided CO2 emissions from 2010 to 2040. Model codes are developed by organizations, such as the International Energy Conservation Code (IECC) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), and then state or localities adopt specific codes. The IECC code and ASHRAE 90.1 standard are widely adopted across the United States.
Sources: 2021 IECC EV Infrastructure Requirements for Residential Buildings; 2021 IECC EV Infrastructure Requirements for Commercial Buildings; Building code ruling may upend EVs, clean electricity; New ICC framework sidelines local government participation in energy code development
In addition to establishing energy efficiency requirements, building energy codes can provide baseline EV charging infrastructure requirements. Further, new buildings are expected to exist for 40 to 50 years and need to be constructed with enough electrical capacity to meet future EV charging demand. Finally, retrofitting a building to incorporate EV charging infrastructure can be 4 to 6 times more expensive than incorporating them into the building during the time of construction. The cost is higher because building owners must install new electrical capacity, demolish and reconstruct parking, run an electrical conduit, and obtain construction permits.
How can building energy codes be used to promote EVs?
State and local governments have several options for adopting building energy codes to promote EVs.
- States and local governments can adopt and modify model building energy codes, such as the 2021 International Energy Conservation Code (IECC) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1 standard (see the box above), which provide minimum EV charging infrastructure for new buildings. They can also adopt overlay codes, such as the 2018 International Green Construction Code (IgCC)–ASHRAE 189.1, which build on the IECC and ASHRAE frameworks but set more aggressive targets.
- States may consider adopting their own energy codes, such as California’s CalGreen code, to help achieve specific statewide objectives.
- Where local governments have the authority to exceed the statewide code, governments can implement stretch codes by adopting voluntary appendices that establish more aggressive baseline standards than what is required in the statewide code. Alternatively, governments can adopt reach codes, or optional construction compliance pathways, to encourage developers to exceed the energy requirements set forth in the statewide code.
- Finally, when local governments do not have the authority to implement reach codes, they may amend their zoning ordinance to require EV infrastructure in new development. EV ordinances typically require EV infrastructure to be installed in buildings in relation to the total amount of parking provided, and often require more EV infrastructure as overall parking amounts increase (e.g., Seattle’s EV Ordinance).
What technological and physical constraints should governments factor into their decisions?
As governments develop policies to expand EV infrastructure, they should be aware that EVSE may be divided into the following three broad categories: Level 1 charging, Level 2 charging, and Direct Current Fast Charging (DCFC). Level 1 charging requires the lowest electricity (typically 120 Volts) and provides roughly 3-4 miles of range per hour of charging. Level 2 charging requires 208-240 V and increases the charging rate to 25-30 miles of range per hour. Finally, DCFC typically provides more than 150 miles of range per hour.
Local governments should consider typical dwell times, or the amount of time a vehicle would stay parked, when developing EVSE policies. Charging EVs with lower power is better where dwell times are longer, while those with higher power are more useful for shorter dwell times. While there are instances where Level 1 EVSE may be appropriate, it would take close to 40 hours to charge a depleted Nissan Leaf battery on Level 1 charging compared to just 8 hours on Level 2 charging. Therefore, where possible, Level 2 EVSE should be pursued as the baseline charging infrastructure, such as in offices and multi-family dwellings.
DCFC (20 kW) can provide 80 percent battery capacity in approximately one hour. Although DCFC provide a quick charge times, given the costs associated with their installation, they are more appropriate for publicly accessible locations, such as grocery store parking lots, where cars will be parked for short periods.
How should ordinances be designed to promote EVs
As governments adopt zoning ordinance amendments to ensure that minimum levels of EV infrastructure are built, they should be cognizant of the spectrum of EV design outlined below:
- EV-Capable means that there is sufficient electric capacity for future EV charging and that a conduit has been run to allow for the future installation of plugs and EVSE.
- EV-Ready indicates that a full circuit (electrical capacity, raceway, conduit, plug, overprotection) is installed.
- EVSE-Installed, as the name implies, denotes that EV charging has been installed, and is the highest level of EV-Ready design.
How can EV policies and plans better ensure equitable outcomes?
Since overburdened communities are often exposed to multiple sources of pollution, prioritizing EV charging locations in disadvantaged communities and reducing the barriers to expanded EV ownership can reduce the overall pollution burden in these communities. As local governments expand access to EVs, they should be aware of the barriers that may prevent disadvantaged communities from benefiting from EV infrastructure.
First, given the existing cost of EVs, LMI EV ownership is relatively low. While federal tax credits help reduce the cost of EVs, most LMI households do not have the necessary tax liability to make them useful. While some states have adopted programs to reduce the cost of EVs for LMI households (such as Connecticut’s CHEAPR program—see the box at left), EV costs may still remain a barrier even as EV prices reach cost parity with ICE vehicles in the next five to six years. Vehicle ownership is lower among poorer households, with 27 percent of households below the poverty line without a vehicle, compared to only 4 percent of households above the poverty line.
Second, people in disadvantaged communities are more likely to live in MUDs, where EV charging infrastructure is less prevalent. Therefore, even if EVs reach cost parity with ICE vehicles, unless there are efforts to expand EV charging for MUDs, then it would be unlikely for EV ownership to expand substantially within LMI households.
Most importantly, local governments should be intentional about including representatives from vulnerable communities in planning processes for EV infrastructure, and should consult best practices for engaging these communities. Providing equal access to the decision-making process will not only ensure that all stakeholders have an opportunity to weigh in on these complex issues but will also lead to more equitable policies.