Technical Article

C&I BESS Outdoor Location per IFC 1207

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Where can you legally install a battery energy storage system (BESS)? Depending on the system’s use case, battery chemistry, nameplate energy capacity, and provisional equipment space, answering this question demands, in part, that we are well-versed in relevant fire codes.

2024 International Fire Code

The clearest statement of requirements for BESS installation location, from a fire safety perspective, can be found in the International Fire Code (IFC) Section 1207, Electrical Energy Storage Systems. The IFC is the model fire code intended for adoption by the state or local authorities responsible for regulating, among many activities, the installation of BESS.  In California, for example, the 2025 California Fire Code (CFC) is a “fully integrated code based on the 2024 [IFC].” Some 40+ states adopt the IFC wholesale or with amendments.

In this article, we will explore how Section 1207 of the 2024 IFC offers guidance for installation locations, focusing on outdoor installations in nonresidential cases.

Location, Location, Location

Information about the many different locations for lithium-based BESS installation is found in several subsections of Section 1207 of the IFC. For behind-the-meter commercial-scale BESS, a basic breakdown of the most common stationary installation locations in the “C&I” markets is as follows:

This is not an exhaustive depiction of where you might see a lithium-ion (Li+) BESS installed per 1207. Yet, this visual captures the most common IFC 1207 subsections for stationary BESS deployment. Indoor installations are generally trending downwards in all markets, but especially in the C&I market. So, the heart of Section 1207’s guidance for most BESS deployments in the C&I sector brings us to 1207.8 Outdoor Installations.

1207.8 Outdoor installations. Outdoor installations shall be in accordance with Sections 1207.8.1 through 1207.8.3. Exterior wall installations for individual ESS units not exceeding 20 kWh shall be in accordance with Section 1207.8.4.

1207.8.1 Remote outdoor installations.
1207.8.2 Installations near exposures.
1207.8.3 Clearance to exposures.
1207.8.4 Exterior wall installations.

A quick understanding here is that we’ll be best served prioritizing 1207.8.2 Installations near exposures. Remote outdoor installations (1207.8.1) are uncommon, as these installations must include a minimum 100 ft setbacks from “other buildings, lot lines, public ways, stored combustible materials, hazardous materials, high-piled stock, and other exposure hazards.” Padmount, skidded, and containerized BESS solutions make up the lion’s share of the C&I market.  Yet, you can find code section tips for exterior wall-mounted installations at the article’s closing. 

Per our now favorite section, 1207.8.2 Installations near exposures, compliance requires we pay attention to Table 1207.8 shown below. Hint: These connected sections in the table match the above visual. Section 1207.8.2  “For the purpose of Table 1207.8, installations near exposures include all outdoor ESS installations that do not comply with Section 1207.8.1 remote outdoor location requirements.”

You should notice that the “Installations Near Exposures” column is  “Yes” all the way down. With this in mind, the rest of this article is presented as a quick reference list paraphrasing each of these yes’s, as shown in Table 1207.8, for any BESS with more than 50 kWh of energy capacity per group installed outdoors near exposures.

Compliance Reference Guide: Outdoor Installations Near Exposures

1207.4. General installation requirements: A dozen subsections itemize a mixed bag of requirements, ranging from working clearances to signage to seismic and structural design.
1207.8.3 Clearance to exposures: This section enumerates the many exposures from which a BESS installation must maintain a minimum 10 ft separation: lot lines, public ways, buildings, stored combustible materials, hazardous materials, high-piled stock, and “other exposure hazards.”
1207.5.5. Fire suppression systems: This subsection regulates the inclusion of automatic sprinkler systems for BESS site, including the BESS’s energy density in a room or area, as determined by large scale fire test data (See 1207.1.7).
1207.5.2 Maximum Allowable Quantity: Aggregate BESS capacity is limited to 600 kWh per fire area. Yes, there are onerous paths to an exception. MAQ deserves a whole article unto itself! Check it out here.
1207.5.6. Maximum enclosure size. How big can an enclosure like a containerized system be before it must comply with the indoor installation code? The container cannot exceed 54 ft x 8 ft x 9.5 ft dimensions.
1207.5.8 Means of egress separation. BESS must be installed with a minimum of 10 ft separation from any means of egress. Fire officials are authorized (but are not required) to reduce this if a large-scale fire test can demonstrate that a fire involving the BESS wouldn’t adversely affect the exit paths in a potential fire scenario.
1207.5.1 Size and separation. Battery “groups” cannot exceed 50 kWh and must maintain a 3 ft separation between groups. There are exceptions enabling larger group sizes and/or reduced spacing between groups, but you will need, you guessed it, data from a large scale fire test. This is a popular topic and this section is worth close consideration. Ryan Mayfield has you covered in this Code Corner episode.
1207.5.4 Fire detection: This subsection adds a requirement for an automatic smoke detection system or radiant energy-sensing fire detection system for walk-in units like containerized systems.
1207.6 Electrochemical ESS technology-specific protection: Li+ BESS is on the hook for two line items of Table 1207.6: Explosion control (1207.6.3) and thermal runaway (1207.6.5). This is a vital subsection that connects our system’s installation to the large scale fire testing as an exception to complying with 1207.6.3, as well as the UL 9540 listing and UL 9540A test method. Join us at our second-annual Education Summit in Seattle this October for a deep dive into the many implications of this subsection.
1207.5.7 Vegetation control: This subsection prohibits combustible vegetation within 10 ft on each side of the outdoor BESS, with limited exceptions for combustion-resistant ground cover vegetation.

IFC 1207 Code Section Tips for other installation-specific guidance

Mobile installations? See Section 1207.10
Indoor installation? Check out 1207.7 for specifics on installing within both dedicated and non-dedicated use buildings. Also, 1207.4.10 further regulates the siting of BESS within occupied work centers.
Residential use cases? Section 1207.11 covers BESS in and near group R3 and R4 type buildings. Start with Ryan’s Code Corner episode first.
What about BESS installed on exterior walls? Individual ESS units cannot exceed 20 kWh and must comply with Section 1207.8.4. These exterior wall-mounted BESS are still considered outdoor installations, so sections such as 1207.5.8 Means of Egress will almost always apply too. Lastly, this 20 kWh limit is most appropriate in Group R3 and R4 type sites (see previous tip). Head to 1207.11.3 for cross-reference.

Beyond the Education Summit in October 2025, Mayfield Renewables has a library of courses to take at your own pace. We also provide design and engineering services for solar-plus-storage systems, including systems installed near exposures. Contact us today for a consultation.