EV Infrastructure Building Codes: Adoption Toolkit




What are EV Infrastructure Building Codes?

EV Infrastructure Building Codes require parking in new buildings to include the electrical equipment necessary to enable the easy and low-cost installation of electric vehicle (EV) charging stations. EV building codes give more people the option to drive an EV by increasing the number of charging stations and by bringing down charger installation costs by 75% or more compared to installing EV chargers during a building retrofit.


Why Do We Need EV Building Codes?

State and local government EV targets and policy

Over the next couple of decades, millions of gas-powered cars will be replaced with electric vehicles, requiring millions of new EV charging stations at homes, offices, rest stops, and shopping centers. State and local governments around the country have adopted bold transportation electrification goals to accelerate EV market growth and unlock the economic and environmental benefits of EVs more quickly. In Colorado, where the number of EVs on the road has more than doubled since 2017, the State set a goal of 940,000 EVs by 2030 (about 15% of total light-duty vehicles) with a long-term goal of 100% electric vehicles. EV infrastructure building codes are an important policy to accelerate the EV market and reduce the costs of meeting Colorado’s ambitious climate and Zero-Emission Vehicle (ZEV) goals.

At the local level, Denver announced a goal to electrify 30% of all vehicles by 2030, which led to the adoption of one of the most ambitious EV building codes in the country, including EV infrastructure requirements for 100% of new parking spaces at multi-unit dwellings (MUDs) in Denver. For local governments, EV building codes are one of the easiest and most affordable strategies to support vehicle electrification in their communities. Once mandatory EV requirements are set in local code, the charging infrastructure automatically spreads throughout the community as neighborhoods grow and evolve, bringing down the cost of charger installations and allowing public and private investments to stretch further over a greater number of new EV charging stations.

Figure 1. 2020-2030 Colorado PEV (Plug-in Electric Vehicle) sales by policy scenario (Navigant, 2019)

The auto industry is shifting toward EVs

In addition to government EV targets and policies, every major automaker in the world has announced a plan to electrify a significant portion of their vehicle fleet over the next 3-5 years. The number of available EV models in the U.S. will grow from 48 in 2020 to over 100 in the next 5 years, and include over 20 electric SUV and pickup truck models. Here’s a complete list of EV commitments from global auto manufacturers, but to name a few:

  • Volkswagen: 70 electrified models by the end of 2028. Investing $91 billion in vehicle electrification. 
  • Toyota: Half of all sales to be electric by 2025.
  • Volvo: 50% of all sales are electric by 2025 (5 new all-electric vehicles by 2021)
  • Hyundai / Kia: 34 EV models by 2025. Investing $112 billion by the end of 2025. 
  • Honda: 2/3 of all sales to be electric by 2030. Every car in the lineup will be EV or hybrid by 2022.

Figure 2. Cumulative Announced US Electric Vehicle Models 2019-2022 by Body Type (MJ Bradley, 2019).

Quantifying the EV charging infrastructure gap

To recharge all these new EVs, we’re going to need millions of new charging stations. A charging infrastructure gap analysis from E3 Consulting found that Xcel Energy needs roughly 15 times more residential, workplace, and public charging stations in their service territory to support Colorado’s goal of 940,000 EVs by 2030:

Figure 3. Number of required charging ports in Xcel Energy’s Colorado territory

The good news is that well over 90% of this new fueling infrastructure is already built in the form of generation, transmission, and distribution on our electricity grid. Now it’s time to tap into that grid and build charging stations in homes, office buildings, shopping centers, and rest stops to recharge all the new EVs coming online. New buildings are built to last for at least 50 years, so it’s critical that charging infrastructure is incorporated at the pre-construction stage to ensure that new buildings can accommodate the charging needs of future EV-owners.

EV building codes expand access to EVs

The lack of access to EV charging is one of the top barriers to EV adoption and the cost to retrofit an existing building with charging stations can be cost-prohibitive for many people. About 50% of Americans do not have access to a dedicated off-street parking space where they can easily install an EV charging station at low cost. For those living in multi-units dwellings (MUDs), the additional cost to install conduit between the electrical panel and their parking space, and the logistical challenges of securing HOA approval, coordinating the EV charger billing with the building owner, and persuading an owner to make a long-term investment on a rental property, are all significant obstacles to EV ownership. Many existing MUD residents must rely on workplace or public charging outside the home, so it’s important that EV infrastructure requirements be included in both residential and commercial building codes. Studies have shown that employees with access to workplace charging are 6 times more likely than the average worker to drive an EV.


Who Has Adopted EV Infrastructure Building Codes?

The following local governments have adopted EV infrastructure building codes:



Cost Implications: EV Building Codes Save People Money

EV building codes require an upfront cost during the initial construction phase, but provide net benefits for EV owners and charging station hosts through the avoided retrofit costs. The installation of EV charging infrastructure is four to six times less expensive when included during the initial construction phase as opposed to a retrofit. The additional retrofit costs typically include labor expenses for demolition, trenching and boring, balancing the circuits, and new permitting costs. Given the momentum toward widespread EV adoption, the cost to pre-wire new buildings with EV charging infrastructure should be compared to the cost of installing the same equipment at a later date during a retrofit, rather than the cost of avoiding such equipment altogether.

For one- and two- family dwellings, the additional costs required to build one EV-Ready parking space during the new construction phase are minimal. Requirements include the installation of one 40-ampere, 208/240-volt dedicated branch circuit (similar to electric dryer or oven) and a circuit terminating in a receptacle, junction box, or EV charging station. The cost to install this equipment during new construction is around $50 depending on the distance between the electrical panel and the parking space. For comparison, Xcel Energy’s Transportation Electrification Plan (TEP) estimates the average cost to retrofit a home with EV-Ready infrastructure at $250 per charger. These costs could easily be higher if the new load triggers an expensive electrical panel upgrade or demolition and reconstruction work to accommodate the new infrastructure.

For multi-family residential and commercial buildings, the costs are substantially higher, both for new construction and retrofits. One study analyzed the cost implications of California’s EV infrastructure building codes, which have been in place for 5 years, and found that each EV-Capable parking space installed in a multi-unit dwelling during new construction saves $2,040 - $4,635 over the retrofit scenario. Multiply those savings by the number of new EV charging stations required to provide charging access for millions of MUD residents and the potential savings amounts to billions of dollars that can be spent elsewhere in the economy. 

Denver’s EV infrastructure building code proposal included the following cost estimates for EV-Capable and EV-Ready parking spaces during new construction and stand-alone retrofit:

These costs are highly dependent on the parking lot configuration, design, and number of EV-Capable or EV-Ready parking spaces. For their code update, the City of Oakland developed a detailed cost-effectiveness report with a range of cost savings estimates for different parking scenarios:

Figure 4. Cost Savings for the City of Oakland (2020)

“Complete circuits” = EV-Ready parking space
“PEV-capable space” = EV-Capable parking space

The cost of EV-Capable infrastructure also varies by building size. A report prepared for the California Electric Transportation Commission measured the cost impact of a 10% EV-Capable parking requirement for small, medium, and large office and retail buildings, including cost estimates for alterations and additions. Larger buildings with more parking spaces reported a lower cost per EV-Capable parking space with economies of scale, but across all building sizes, the cost to install EV-Capable infrastructure during new construction is four to six times less expensive than during a stand-alone retrofit

Figure 5. Estimated Cost of Installing EV Capable Parking per EV Capable Parking Space.
Refer to Table 7 in the report for a more detailed breakdown of the costs by type of expense.

The EV infrastructure costs may seem high, but the overall impact on building costs is low. An analysis done by the California Air Resources Board in 2018, examined the costs of adding EV Ready requirements for new multi-family developments. It found that adding panel capacity and conduit during new construction would add between 0.1% and 0.2% to the total building cost. 

Why is it so much less expensive to install EV-Capable infrastructure during new construction versus a retrofit?

Several factors contribute to higher costs:

  • Demolition and repair of surface parking.
  • Breaking and repairing walls.
  • Longer conduit runs (also referred to as raceways) – Removing and repairing 100 - 300 linear feet of surface parking to add conduit can cost $11,500 to $32,000 in demolition and repair costs.
  • Upgrading electric service panels.
  • Soft costs: permits, plans, inspections, and project management.

In addition to cost considerations, many developers and building owners have recognized that EV charging infrastructure is an increasingly important amenity for many tenants and home buyers. EV infrastructure building codes support a more accessible and competitive housing market, while also providing a standard set of definitions for developers and contractors to build from.


Electrical Capacity Requirements: Why Level 2 Instead of Level 1?

Level 2 charging stations offer more control and flexibility for EV owners and site hosts because they’re faster and more intelligent. Many “early adopters” of EVs use Level 1 charging (20-ampere, 120-volt) to recharge their vehicles at home, which is sufficient for most Plug-in Hybrid Electric vehicles (PHEVs) and battery-electric vehicles (BEVs) that stay local and don’t drive very far. Level 2 charging is 6-7 times faster and gives EV drivers more flexibility to fully recharge their vehicles overnight, take advantage of lower time-of-use electricity rates during off-peak periods, and from a electricity grid perspective, unlock the potential to improve grid efficiency and integrate more renewables with managed charging. 

Level 2 charging stations (40-ampere, 240-volt) add 25-30 miles of range per hour compared to 3-5 miles of range per hour with a Level 1 charger. For context, a Level 1 charging station could take over 40 hours to fully recharge a Nissan LEAF vs about 8 hours with a Level 2 charging station. 

In the early days of EVs, from 2011 to 2017, 75% of sales were plug-in hybrid electric vehicles (PHEVs), which have both an electric motor with a limited all-electric range (20-50 miles), and a backup gasoline engine for longer trips. The remaining 25% of sales were battery-electric vehicles (BEVs), which are all-electric and have longer ranges of 200-300+ miles. In the last few years, the EV market share has reversed, and in 2019, 75% of EV sales were BEVs and 25% were PHEVs. As battery prices continue to fall, future BEVs will have larger batteries and longer ranges of 300 miles or more per charge. While it’s rare for most people to drive more than 50 miles in a day, most EV drivers want the flexibility to fully recharge their vehicle overnight with a faster Level 2 home-charger.

Figure 6. Colorado GHG Roadmap Study – Light Duty Vehicles Sales Share Projections (2015-2050)
anticipates the vast majority of future EV sales will be BEVs with 100% market share by 2035.

In addition, Level 2 home-charging allows EV owners to take advantage of time-of-use (TOU) rates and save money on their electricity bills. TOU rates have different prices for on-peak and off-peak hours and are meant to align prices more closely with the actual costs of providing electricity during those hours. By charging EVs during the low-cost off-peak hours, EV drivers can save money while also reducing costs to the grid and putting downward pressure on rates for all utility customers. In addition, Level 2 circuits give site hosts the flexibility to distribute the load across multiple EVs with load management software. Such time-varying rates can also be designed to align EV charging with surplus renewable generation to increase the amount of clean energy on the grid.


What to Include in EV Infrastructure Building Codes

Basic definitions:

EV-Capable Parking Space: Electrical Panel Capacity & Conduit

  • Install panel capacity and conduit (raceway) to accommodate the future build-out of EV charging with 208/240 V, 40-amp circuits.
  • Rationale: Provide hard-to-retrofit elements during new construction while minimizing up-front cost. 

EV-Ready Parking Space: Install full circuit

  • Full circuit installations include 208/240V, 40-amp panel capacity, raceway, wiring, receptacle, and overprotection devices similar to a dryer circuit.
  • Rationale: Full circuits are plug-and-play ready and minimize total costs and additional barriers to installing Electric Vehicle Supply Equipment (EVSE).

EV-Installed: Install EV Charging Station (also known as Electric Vehicle Supply Equipment or EVSE).

  • Install charging stations during new construction.
  • Rationale: Provide a visible signal that building supports EV charging and reduce future EV charger installation costs to zero.

Existing Buildings (Alterations): Additions, Major Building Alterations, Surface Parking and Electrical System Upgrades

  • Level 3 Alteration: “where the work area exceeds 50 percent of the original building area or more than 10 parking spaces are substantially modified.” (definition taken from Denver EV building code proposal).
  • Rationale: Buildings typically have a 50-year lifespan and should be retrofitted during significant alteration or additions to support EV charging.

Electric Vehicle Load Management System

  • A system designed to allocate charging capacity among multiple EV charging stations at a minimum of 8 amps per charger (minimum allocation may vary).
  • Rationale: Increase cost-effectiveness by allowing the system to “share” the load across multiple EVs in the parking lot depending on their charging needs. 

EV technology is new for most consumers and general awareness about EV charging is lagging. A recent Colorado-specific survey found that 54 percent of respondents did not think they could charge an EV at home by plugging it into a standard three-prong wall outlet, which is how 90 percent of EV owners recharge their vehicles. In reality, the basic charging equipment for Level 2 home-charging is very similar to other home appliances.

Figure 7. Basic Charging Equipment

*In some cases, EV charging cables are included in the purchase of a new EV, such as the Nissan LEAF.


EV Infrastructure Requirements: Model Code Language

Core requirements

At a minimum, local governments should adopt the EV infrastructure requirements from the 2021 IECC model code, which include: 

  • One- and two-family dwellings: At least one EV-Ready parking space per dwelling unit. EV-Ready parking spaces have a 40A, 240V dedicated branch circuit for the future installation of an EV charger.
  • Multi-family dwellings (3+ dwellings): Two EV-ready parking spaces and EV-Capable infrastructure (the electrical panel capacity and raceway, but not wiring), for 20% of the total parking spaces.
  • Commercial buildings (Groups A, B, E, I, M, S-2): Two EV-ready parking spaces and EV-Capable infrastructure (the electrical panel capacity and raceway, but not wiring), for 20% of the total parking spaces.

2021 IECC EV requirements: In 2019, SWEEP proposed new EV infrastructure building code requirements for the 2021 International Energy Conservation Code (IECC). The new mandatory requirements were approved by the online vote of ICC members and await final approval in late 2020: 

Rationale for a Minimum Requirement
Seattle, Chicago, and Atlanta have all adopted a 20% EV infrastructure requirement for parking lots in new MUD and commercial buildings. This minimum requirement is a good start and provides enough electrical capacity to give property managers load management flexibility to distribute the EV charging across a higher penetration of EVs as the population grows. 

20% EV Readiness is designed for a future scenario where 20% of vehicles in the parking lot are longer-range (200+ miles) all-electric vehicles and can be fully charged overnight in an 8-10 hour period. However, the average American drives about 30 miles per day with the occasional longer road trip to visit family or adventure in the mountains. Under a 20% EV Readiness scenario, buildings would be outfitted to support additional EV drivers beyond the 20% penetration with minimal additional cost. A minimum 20% electrical capacity allows for Load Management Software to ‘share’ load and allow reasonable charge times for 100% of spaces in residential and workplace applications. For example, in a future scenario where 100% of vehicles in a parking lot are electric, 20% EV Readiness would provide enough capacity to deliver 60 miles of range, about double the average daily mileage, to each vehicle overnight. This would require basic load management equipment and software to communicate the current and desired state of charge for each EV, and throttle down the charging station power to distribute the electricity in a way that satisfies the needs of each driver. 

Progressive Requirements:
Local governments targeting higher EV adoption should consider more ambitious EV infrastructure requirements for 100% of new parking spaces. Denver’s new building codes require: 

  • One- and two-family dwellings: At least one EV-Ready parking space per dwelling unit. EV-Ready parking spaces have a 40A, 240V dedicated branch circuit for the future installation of an EV charger.
  • Multi-family dwellings (3+ dwellings) with 10+ spaces: 5% of parking spaces to be EV-Installed (complete charging station), 15% EV-Ready Parking Spaces, and 75% EV-Capable Parking Spaces.
  • Commercial buildings (Groups A, B, E, I, M, S-2) with 10+ spaces: 5% of parking spaces to be EV-Installed (complete charging station), 10% EV-Ready Parking Spaces, and 10% EV-Capable Parking Spaces.
  • Building Alterations: ‘Level 3 Alterations’, where the work area exceeds 50 percent of the original building area or more than 10 parking spaces are substantially modified are subject to the EV infrastructure requirements listed above. 
  • DC Fast-charger provision: For MUD and Commercial buildings, allow developers to substitute up to five Level 2 charging spaces with one DC fast-charging space (minimum 20kW). 

Link to the City and County of Denver’s updated EV Infrastructure Building Code Proposal.

Moving toward 100% EV-Capable in residential buildings
Denver, Oakland, Vancouver and others have all adopted requirements for 100% of parking spaces in MUDs to be EV-Capable. Such a requirement simplifies EV parking management and enables dynamic load management systems by giving residents and property owners the flexibility to install chargers wherever it's most convenient for users, regardless of whether they park in a shared or assigned parking configuration.