BESS and Substation Screening: NFPA 855 and Zoning Rules

Battery energy storage screening is the fence, wall or planting around a battery energy storage system (BESS) or substation that keeps people out and hides the equipment from view. Three rule sets shape it: the local zoning code, the fire code based on NFPA 855, and the electrical code. Different reviewers check them, and they do not always agree. This guide shows what each asks for, with real examples, so the perimeter on your site plan passes all three. For ordinary HVAC and ground equipment, see mechanical equipment screening requirements. The project engineer, fire code official and planning department make the final calls.

What do BESS ordinances require for fencing and screening?

Most BESS ordinances require a locked fence of 6 to 8 feet around the system and some form of visual screening from neighbors and streets. The details sit in the zoning code, so they are checked at site plan or special permit review. Two adopted examples show the range:

Example	Fence	Visual screening	Other conditions
One county's zoning code (larger systems)	8 ft tall with a self-locking gate, unless the system is in a dedicated building; must not interfere with ventilation or exhaust ports	Landscaped buffer around the perimeter. Trees 6 ft tall within 3 years and a mature height of 12 ft or the fence height, whichever is taller	10 ft cleared of combustible vegetation; 60 dBA noise limit; fencing shown on the site plan
One city's zoning regulations (over 80 kWh)	At least 6 ft, with a self-locking gate or other locking mechanism required by the building and fire codes	Substantially screened from public view by landscaping or an opaque fence or wall. Transformers also screened	Vehicle barrier if within 25 ft of parking or a driveway; shielded lighting; 15 ft height limit

Many communities are writing their first BESS rules now. Read the code for your parcel, and check whether it is adopted or still a draft.

What does NFPA 855 require around an outdoor BESS?

NFPA 855 sets the fire-safety spacing around the equipment, not its appearance. Most jurisdictions apply it through the International Fire Code. The 2024 IFC, Section 1207 marks these provisions as based on the 2023 edition of NFPA 855:

• Clearance to exposures (1207.8.3). Outdoor ESS must be at least 10 ft from lot lines, public ways, buildings, stored combustible materials, hazardous materials, high-piled stock and other exposure hazards.
• Remote installations (1207.8.1). Equipment more than 100 ft from those exposures is treated as remote, and some requirements relax.
• Vegetation control (1207.5.7). The area within 10 ft on each side of outdoor ESS must be cleared of combustible vegetation. Single specimen trees and cultivated ground cover can be exempt if they do not readily spread fire.
• Means of egress (1207.5.8). At least 10 ft from any exit path.
• Securing the installation (1207.4.9). ESS areas must be secured against unauthorized entry in an approved manner, and fences, barriers and landscaping "shall not inhibit the required air flow to or exhaust from" the equipment.

NFPA 855 is now in its 2026 edition. Which edition applies depends on what your state or city has adopted, so confirm it with the fire code official.

Does NFPA 855 require a fence?

It requires the installation to be secured, but it does not set a fence height or a material. The fire code official approves the method. The height usually comes from zoning or from the electrical code, covered below.

Can a screen wall reduce the 10 ft clearance?

No, not a typical screen. The code lets the clearance drop to 3 ft only with specific protection, such as a 1-hour free-standing fire barrier suitable for exterior use that extends 5 ft above and 5 ft beyond the ESS. A slatted steel screen has no fire-resistance rating. It is noncombustible, but it is not a fire barrier, and it does not change any NFPA 855 separation.

How tall does a BESS or substation fence have to be?

For outdoor electrical equipment over 1,000 volts, the National Electrical Code sets a floor of 7 ft. NEC Section 110.31 requires "a wall, screen, or fence" to enclose the installation and keep unqualified people out. A fence must be at least 7 ft tall, or 6 ft of fabric plus a 1 ft extension with three or more strands of barbed wire or equivalent. It also sets a minimum distance from the fence to live parts that grows with voltage.

Zoning then adds its own minimum, often 8 ft. Utility-owned substations normally follow the National Electrical Safety Code and the utility's own standards, so get those criteria from the utility before the layout.

Watch for a conflict: some zoning codes prohibit the NEC's barbed-wire option, and planners often want a solid face rather than chain link. A solid wall or screen built to the full height meets the height rule without barbed wire. Alpine Citadel comes in standard heights of 6, 7 and 8 ft, with custom heights from 5 to 10 ft.

What do cities require to screen a substation?

Many zoning codes require substations and similar utility facilities to be screened from view, often with a tall masonry wall. One city's zoning code is a clear example:

• Screening for electric substations is scaled to the facility and is generally 8 to 12 ft tall.
• Masonry walls are the default, with decorative metal allowed in limited places for visibility, ventilation and access.
• Steel fencing is allowed through the planning director's discretionary review.
• Chain link, barbed wire, corrugated metal and plain wood are prohibited.
• Screening walls 4 ft or taller need a design sealed by a licensed professional engineer.

Where a code names masonry, a steel screen goes through an alternate-materials or discretionary review. Bring sealed calculations, the finish and color, and elevations to that review. Metal near energized equipment also has to fit the station's grounding design. The utility or the electrical engineer sets that, so share the requirement before layout.

Solid screen or open infill: what about airflow?

Airflow decides the infill. The fire code says fences and screens must not block the air the equipment needs. Air intake and exhaust locations differ by product, and one ordinance above makes the same point about ventilation and exhaust ports.

• Solid slats, stacked tight. The standard Alpine Citadel face is 100% opaque. It suits sites where the screen sits well clear of the equipment's air paths.
• Spaced slats or perforated metal panels. Custom options that let air pass through the face. Partial opacity may or may not satisfy an "opaque" screening rule, so ask the planner.

The equipment supplier and the fire-protection engineer should confirm the air paths and the distance from the screen to the equipment before the infill is chosen. Infill and height options are on the utility, data center and BESS screen walls page.

How should gates handle fire department access?

Size and lock the gates with the fire department. Ordinances call for self-locking gates. The IFC requires fire apparatus access roads to be 20 ft wide, except at approved security gates, and gates across those roads must be approved by the fire code official with an approved means of emergency operation. The official can also require a key box or an approved lock.

Alpine Citadel gates come in standard 12 ft and 16 ft clear openings, with 20 ft clear as a custom option. Each has a heavy-duty lockable latch box and cane bolts, and every gate is function-tested before shipping.

Will a screen reduce BESS or transformer noise?

No. A slatted screen is a visual screen, not a noise barrier. Noise limits such as the 60 dBA limit in the county example above are met through equipment selection, layout and, where needed, a separate acoustic design by an acoustical consultant.

Does a BESS or substation screen need wind engineering?

Yes. An 8 ft solid screen on an open site takes a large wind load, and energy sites are often open terrain. Alpine Citadel is engineered to ASCE 7-22 for each site's wind speed, exposure category and risk category, with no single wind rating. Closer post spacing, heavier base plates or embedded posts handle higher-wind sites. See how ASCE 7-22 sets screen wall wind load.

How can developers and utilities set one screening standard?

A team building many storage or substation sites can write one perimeter detail to the strictest common requirements and adjust it per site. From the rules above, a standard that travels well looks like this:

• Height of 8 ft, which clears the NEC's 7 ft and common 8 ft zoning minimums without barbed wire.
• An opaque face where neighbors or streets can see it, with spaced slats or perforated panels where the equipment needs air.
• Noncombustible material, and any planting kept outside the 10 ft vegetation zone.
• Self-locking gates sized and keyed with the fire department.
• Grounding per the utility or electrical engineer, and wind design per site.

Alpine Citadel is structural steel throughout, ASTM A36 or equivalent, with no aluminum components, finished in any RAL color. Sealed calculations are available in all 50 states, and the engineering package takes under one week. See Alpine's national programs for program kitting by site and release.

What should the site plan show?

1. The zoning section and the fire code edition you are meeting, quoted on the sheet.
2. The fence or screen line, height and infill, with the opaque segments marked.
3. The 10 ft clearances to lot lines, buildings and exit paths, and the 10 ft vegetation zone.
4. Equipment air intake and exhaust zones from the supplier, with the screen's distance to them.
5. Gates: clear width, swing, locking, and the fire department key box if required.
6. Landscaping outside the screen: species, size at planting and spacing.
7. The minimum fence-to-live-parts distance and the grounding approach, from the electrical engineer.
8. Wind design criteria and who provides sealed calculations.

If you have a planning condition or a perimeter detail to settle, send the site plan, the equipment layout and the fire department's comments through the Alpine quote request. Alpine will lay out the screen and gates to your drawing and confirm height, infill and engineering for the site.

Sources

• International Code Council. 2024 International Fire Code, Chapter 12, Section 1207 Electrical Energy Storage Systems (and Sections 503.2.1, 503.6, 506.1). 2024.
• National Fire Protection Association. NFPA 855, Standard for the Installation of Stationary Energy Storage Systems. 2023 and 2026 editions.
• National Fire Protection Association. NFPA 70, National Electrical Code, Section 110.31 Enclosure for Electrical Installations. 2023.
• Johnson County. Code of Ordinances 8:1.24.F, Battery Energy Storage Systems, Tier 2. Amended through 2024.
• City of Bristol. Zoning Regulations, Section 5.4.7, Battery Energy Storage Systems. Effective 2025, amended 2026.
• City of Celina. Zoning, Article 14.04 Part 3, Screening Walls and Fences. 2026.