Fire Service Access Elevators Explained

What are Fire Service Access Elevators (FSAE)

Fire Service Access Elevators or F.S.A.E. for short, are designed with strict and rigorous standards to allow firemen and first responders to utilize the elevator for the purpose of quickly accessing floors as well as evacuating occupants in the event of an emergency.  This is a huge step for first responders as time is extremely crucial when addressing buildings of this size.

Another special condition for elevators is known as Occupant Evacuation Elevators.  These are self-evacuation elevators with special requirements much like FSAEs.

Fire Service Access Elevators

What Code Requires the Use of Fire Service Access Elevators?

Did you know the 2021 International Fire Code now requires 120 VAC single and multiple station smoke alarms to produce a 520 Hz low frequency audible tone? 

The requirement to provide fire service access elevators can be found in the IBC or International Building Code 2021 section 403.6.1

"In buildings with an occupied floor more than 120 feet above the lowest level of fire department vehicle access, no fewer than two fire service access elevators, or all elevators, whichever is less, shall be provided in accordance with section 3007.  Each fire service access elevator shall have a capacity not less than 3500 pounds."

The requirements on how a fire service access elevator is to be installed can be found in the IBC or International Building Code 2021 section 3007.

Other references include:

• ASME A17.1
• CSA B44
• NFPA 72 2022 section 21.5

Requirements of Fire Service Access Elevators

When a fire service access elevator is required by the IBC section 403.6.1, every floor within the building shall be served and comply with sections 3007.1 through 3007.9

Automatic Sprinkler Requirements:

The building with FSAE shall be protected throughout with an approved automatic sprinkler system in accordance with section 903.3.1.1.  The automatic sprinkler system shall be provided with a supervised tamper switch and alarm initiating water flow switch on every floor of the building.  Note, the following areas are prohibited from having automatic fire sprinkler protection:

• Elevator Machine Rooms  
• Elevator Machinery Spaces
• Elevator Control Rooms
• Elevator Control Spaces
• Elevator Hoistways of the Fire Service Access Elevator

The lobby on each floor served by the fire service access elevator shall have an approved method of preventing water from the operation of the automatic sprinkler system from infiltrating the FSAE hoistway.

Lastly, a means for elevator shutdown or Shunt Trip in accordance with IBC section 3005.5 shall NOT be installed on elevator controllers used for fire service access elevators.

Fire Service Access Elevator Hoistway Enclosure

The shaft or hoistway enclosure shall comply with IBC section 713 "Shaft Enclosures" as well as section 403.2.3.1 "Wall Assembly" and sections 403.2.3.4 "Other Wall Assemblies".

Another important aspect to keep in mind is the hoistway lighting for the FSAE shaft.  When the Fire Service Access operation is active, the entire height of the hoistway shall be illuminated at NOT less than 1 footcandle (11 lux).  This measurement is to be taken from the top of each fire service access elevator cab.  

**The fire service access elevator status panel (located in the FCC room) shall have a switch to manually operate this lighting feature.    

Fire Service Access Elevator Cab Dimensions

Although this is not a direct requirement for FSAE rather buildings that are four stories or more, it still applies and is worth mentioning.  IBC section 3002.4 "Elevator Car to Accommodate Ambulance Stretcher" gives us the dimensions required for the cab.  "The elevator car shall be of such a size and arrangement to accommodate an ambulance stretcher 24 inches by 84 inches with not less than 5 inch radius corners, in the horizontal, open position.  ADA Table 407.4.1 breaks this down a little further and gives us the following:  The cab shall be provided with a minimum clear distance between walls and door excluding return panels not less than 80 inches by 54 inches and a minimum distance from wall to return panel not less than 51 inches with a 42 inch side slide door.

Fire Service Access Elevator Car Dimensions

FSAE Lobby Requirements

Egress through the fire service access elevator lobby is permitted in accordance with IBC section 1016.2 "Egress Through Intervening Spaces" item #1.  The exception to this rule is if the FSAE lobby has two entrances onto the floor, the second entrance shall be permitted to open into an elevator lobby in accordance with IBC section 3006.3 "Hoistway Opening Protection".

The fire service access elevator lobby shall have direct access to to an enclosed interior exit stairway or ramp.  The interior exit stairway or ramp can be in a protected pathway that has a level of protection not less than the FSAE lobby.  The path of travel and FSAE lobby shall be separated via an opening protected by a smoke and draft control assembly in accordance with IBC section 716.5.3 "Door Assemblies in Corridors and Smoke Barriers".  

The FSAE lobby enclosure shall have smoke barrier having a fire-resistance rating of not less than 1 hour.  The FSAE lobby doors shall be 3/4 hour fire door assemblies in accordance with IBC section 716.5 "Fire Door and Shutter Assemblies".  This rule does NOT apply to the hoistway doors, elevator control room doors or elevator control space doors.  Fire Service Access Elevators (FSAE) lobbies are not required to be enclosed at the levels of exit discharge.

Keep in mind the elevator lobbies for fire service access elevators shall be no smaller than 150 square feet in area with a dimension not less than 8 feet.  This rule applies no matter how many FSAE cabs are served by the same lobby.  Example 8 feet x 19 feet would give you 152 square feet of lobby area.  

Fire Service Access Elevator Stretcher

How are Fire Service Access Elevators Designated or Noticed?

IBC section 3007.6.5 gives us the following information.  A pictorial symbol of a STANDARDIZED design shall be placed on each side of the hoistway door frame on the portion of the frame at right angles to the fire service access elevator lobby.  To clear that up, the symbol shall be installed on the frame where it is noticeable immediately upon entry to the FSAE lobby.

Here is a picture of the symbol depicted in the IBC figure 3007.6.5

Fire Service Access Elevator Symbol

The following are guidelines for the design of the symbol:

• The FSAE symbol shall not be less than 3 inches in height
• The helmet shall contrast the background.  It states you can use a dark helmet on light background or light helmet on dark background.
• The symbol shall be located on center line of the symbol and FSAE door frame at a height of not less 78 inches or more than 84 inches.  

FSAE Monitoring

The fire service access elevators shall be continuously monitored at the FCC by a standard emergency service interface system meeting requirements found in NFPA 72 the National Fire Alarm and Signaling Code.

FSAE Electrical Power

The following that serve each fire service access elevator shall be provided with both normal power as well as Type 60/Class 2/Level 1 standby power:

1. Elevator equipment
2. Elevator hoistway lighting
3. Ventilation for elevator machine rooms, elevator control rooms, machine and control spaces.
4. Elevator cab lighting

He is the big one to watch out for.

Protection of Wiring and Cables for Fire Service Access Elevators

Wires and cables located OUTSIDE of the fire service access elevator lobby and machine room that are provided for the fire-detection system shall be protected by construction having a fire-resistance rating of not less than 2 hours, shall be circuit integrity (CI) cable with a rating of not less than 2 hours or shall be protected by a listed electrical protective system having a rating of not less than 2 hours.

Phase 1 Recall for Fire Service Access Elevators

This is currently taken from our home state of California out of the California Building Code 2013 of CBC section 3007.2.  Activation of ANY initiating device within the building shall active the phase 1 recall of all fire service access elevators.  All standard elevators shall remain in the normal operation unless they are manually taken over via key or the activation of their associated fire alarm initiating devices.  

Firemen Inside Elevator Cab FSAE

NFPA 72 Requires Elevator Lobby and Equipment Rooms to Monitor the Presence of Heat 

NFPA 72 2019 section 21.5 requires an approved means for firefighters to monitor smoke and heat conditions in the FSAE lobbies and associated machine/control rooms.  This is intended to provide firefighters with more information to determine whether the FSAE lobby protection has been compromised. This means shall include a dedicated FSAE Status Panel located at the FCC. (Reference NFPA 72-2019 Section 21.5 indicated in item 4.g below).  For Notifier we use the addressable FMM-4-20 module along with a Veris Industries TW or TE wall mounted temperature sensor.  We then provide a custom LED status panel from the H.R. Kirkland Company Inc. with each elevator lobby broken down into 3 temperature levels.  See image below of a Fire Service Access Elevator Status Panel for San Francisco, CA.

Read this article to see how Notifier is accomplishing the monitoring of individual temperature ranges within each fire service access elevator lobby.  "Temperature Sensors for Fire Service Access Elevators"

Fire Service Access Elevator Status Panel

In closing fire service access elevators are a fairly new setup allowing fire fighters and first responders to access the elevators in the event of a fire.  Since these lifts are established as Fire Service Access Elevators, they must meet some very strict rules to ensure they are safe and will function in the extreme conditions of a structure fire.

All code references for this article are found in the 2021 Edition of the International Building Code.

Are Low Frequency Sounders Required by Your AHJ

520Hz Low Frequency Sounders 

"Effective January 1st 2014, audible appliances provided for the sleeping areas to awaken occupants shall provide a low frequency alarm signal that complies with the following:  (1) The alarm signal shall be square wave or provide equivalent awakening ability.  (2) The wave shall have a fundamental frequency of 520 Hz +/- 10 percent."

We got a glimpse of the future requirement in the 2010 Version of NFPA 72 section 18.4.5.3 page 102.  Here we could see that come January 1st 2014, there would be a requirement for fire alarm designers to use a 520Hz square wave low frequency sounder within all sleeping areas.  There have been multiple studies performed that validate the belief that a 520 Hz low frequency audible tone will have a greater chance at awakening a sleeping occupant.  The lower frequency also has greater chances of awakening people whom are intoxicated or hard of hearing.

Lets fast forward to the 2016 edition of the standard.  NFPA 72 version 2016 notes the same requirement in section 18.4.5.3 page 112.

Click to listen to a 520Hz Low Frequency sound file.  Or a 3KHz tone typically used prior to 520Hz requirements.

Now, here we are in the year 2016 and yet not everyone is following this standard.  You may ask yourselves why is our AHJ or authority having jurisdiction not requiring our fire alarm installation company to install the new 520Hz low frequency sounders for sleeping areas.  Keep in mind that the particular state you install fire alarms in may have an older code adopted.  Click to learn the difference between fire alarm codes and standards.

How do you know if your state or region is requiring 520Hz low frequency sounders?

The International Fire Code or IFC 2018 edition chapter 80 as well as the International Building Code or IBC 2018 edition chapter 35 both reference NFPA 72 2019.  With this said, you will need to find out if your jurisdiction has adopted the 2012 or newer version of the IBC or IFC code.  Better yet, System Sensor has provided a detailed map of the States and Regions currently adopting this code.  See below:

IBC Occupancy Classifications for Fire Alarm

Occupancy Classifications Based on the International Building Code

Occupancy classifications are broken down in the 2021 IBC or International Building Code Chapter 3 "Occupancy Classification and Use". These different groups are made up for different uses and structures.  As you guessed, each occupancy classification has its own fire alarm system requirements. These fire alarm requirements are found in the IFC or International Fire Code section 907.  Below is a simple breakdown of what each occupancy classification is used for.  We have also included links that will take you directly to the fire alarm requirements for each group.

Occupancy Group Classifications

Assembly Group A Occupancy:  

Section 303.1 - Uses intended for the gathering together of persons for the purposes such as civic, social or religious functions, recreation, food or drink consumption or awaiting transportation. 

Section 303.1.1 -  A building or tenant space used for assembly purposes with an occupant load of less than 50 persons shall be classified as a group B occupancy.  

Section 303.1.2 - A room or space used for assembly purposes with an occupant load of less than 50 persons or less than 750 square feet in area and accessory to another occupancy shall be classified as a Group B occupancy or as part of that occupancy. 

Section 303.1.3 - Assembly rooms which are accessory to Group E are not considered as Group A.

Section 303.1.4 - Religious education rooms and auditoriums with occupant loads less than 100 persons which are accessory to churches or places of special worship, shall not be considered separate occupancies. 

Please refer to section 411 of the 2021 International Building Code for Special Amusement areas.

Note that a building or tenant space used for assembly purposes with an occupant load of less than 50 persons shall be classified as a Group B occupancy. A room or space for assembly purposes that is less than 750 square feet in area or accessory to another occupancy shall be classified as a group B occupancy or as part of that occupancy. 

Group A is divided into five sub groups as follows:

A-1: Assembly use. Usually with fixed seating, intended for production and viewing of the performing arts or motion pictures. This could include but not limited to motion picture theaters, Symphony and concert halls, television and radio stations admitting an audience, and theaters.

A-2: Uses intended for food and drink consumption. This could include but not limited to banquet halls, casino gaming areas, night clubs, restaurants, cafeterias and similar dining facilities including associated commercial kitchens, taverns, and bars.

A-3: Uses intended for worship, recreation or amusement and other assembly uses not otherwise classified. This could include amusement arcades, art galleries, bowling alleys, community halls, courtrooms, dance halls, exhibition halls, funeral parlors, greenhouses for the conservation and exhibition of plants that provide public access, gymnasiums without spectator seating, indoor swimming pools without spectator seating, indoor tennis courts without spectator seating, lecture halls, libraries, museums, places of religious warship, pool and billiard parlors, and waiting areas in transportation terminals.

A-4: Uses intended for viewing of indoor sporting events and activities with spectator seating. This can include but not limited to arenas, skating rinks, swimming pools, and tennis courts.

A-5: Uses intended for participation in or viewing outdoor activities. This can include but not limited to amusement park structures, bleachers, grandstands, and stadiums. 

Click here to find out what fire alarm equipment is required for Group A Occupancy.

Business Group B Occupancy:  

Assembly occupancies less than 50 persons and/or uses intended for office, professional or service type transactions, including storage of records and accounts. Group B occupancies can include but are not limited to the following: Airport traffic control towers, ambulatory care facilities, animal hospitals, kennels, pounds, banks, Barber and beauty shops, car washes, civic administration, clinics and outpatient facilities, dry cleaning and laundry facilities, educational occupancies for students above the 12th grade including higher education laboratories, electronic data processing, food processing establishments and commercial kitchens not associated with restaurants, cafeterias and similar dining facilities not more than 2500 square feet in area, Laboratories for testing and research, motor vehicle showrooms, post offices, print shops, professional services (architects attorneys, dentists, physicians, engineers, etc.), radio and television stations, telephone exchanges, training and skill development not any school or academic program this shall include but not limited to tutoring centers, Martial arts studios, gymnastics and similar uses regardless of the ages served, and where not classified as a group a occupancy. 

For additional information on airport traffic control towers, please refer to the 2021 International Building Code (IBC) section 304.2.

For additional information on ambulatory care facilities, please refer to the 2021 International Building Code (IBC) section 304.3.

For additional information on higher education laboratories, please refer to the 2021 International Building Code (IBC) section 304 .4.

Click here to find out what fire alarm equipment is required for Group B Occupancy.

Educational Group E Occupancy:  

Section 305.1 - Uses intended by 6 or more persons at any time for educational purposes through the 12th grade.  

Section 305.2 - Group E daycare uses for educational, supervision or personal care services for more than 6 children older than 2 and a half years of age. 

Section 305.1.1 - Religious education rooms or auditoriums that have an occupant load of less than 100 per room or space shall be classified as Group A-3 occupancies.

Section 305.2.3 - A facility having five or fewer children receiving such daycare shall be classified as part of the primary occupancy.

Click here to find out what fire alarm equipment is required for Group E Occupancy.

Factory Industrial Group F Occupancy: 

Uses intended for assembling, disassembling, fabricating, finishing, manufacturing, packaging, repair or processing operations that are not classified as Group H Hazardous or Group S Storage.  Group is divided into two sub groups.

Group F-1: Moderate Hazard - Factory industrial uses that are not classified as factory industrial F-2 low hazard shall be classified as F-1 moderate hazard and shall include but are not limited to the following: Aircraft manufacturing not including repair, appliances, athletic equipment, automobiles and other motor vehicles, bakeries, beverages over 16 per cent alcohol content, bicycles, boats, brooms and brushes, business machines, camera and photo equipment, canvas or similar fabric, carpets and rugs including cleaning, clothing, construction and agricultural machinery, disinfectants, dry cleaning and dying electric generation plants, electronics, energy storage systems in dedicated use buildings, Engines including rebuilding, food processing establishments and commercial kitchens not associated with restaurants, cafeterias and similar dining facilities more than 2500 square feet in area, furniture, hemp products, jute products, laundries, leather products, machinery, metals, millwork, motion pictures and television filming without spectators, musical instruments, optical goods, paper mills or products, photographic film, plastic products, printing or publishing, recreational vehicles, refuse incineration, Shoes, soaps and detergents, textiles, tobacco, trailers, upholstering, water and sewer treatment facilities, would distillation, and woodworking.

Group F-2: Low Hazard - Factory industrial uses that involve the fabrication or manufacturing of non combustible materials that during finishing, packing or processing do not involve a significant fire hazard shall be classified as F-2 occupancies and shall include but not limited to the following: Beverages up to and including 16% alcohol content, brick and masonry, ceramic products, foundries, glass products, gypsum, ice, and metal products (fabrication and assembly).

Click here to find out what fire alarm equipment is required for Group F Occupancy.

High-Hazard Group H Occupancy:  

Uses intended for manufacturing, processing, generation or storage of materials that constitute a physical or health hazard in quantities in excess of those allowed .  Group H is divided into 5 sub groups.

Group H-1: Detonation Hazard

Group H-2: Deflagration Hazard or Accelerated Burning

Group H-3: Materials that readily support combustion or pose a physical hazard.

Group H-4: Materials are health hazard

Group H-5: Semiconductor fabrication facilities and comparable R&D areas which HPM's are used.

Due to the complex nature and multiple types of combustible/explosive material, we highly recommend you review the direct requirements found in section 307 of the 2021 International Building Code (IBC) to verify which group H occupancy your facility will be classified as. Tables 307.1(1) and 307.1(2) will provide additional information as well.

Click here to find out what fire alarm equipment is required for Group H Occupancy.

Institutional Group I Occupancy:  

Uses intended in which people are cared for or live in a supervised environment, having physical limitations because of health or age are harbored for medical treatment or other care or treatment or in which the liberty of the occupants is restricted.  Group I is divided into four sub groups.

Group I-1:  Houses more than 16 persons, on a 24 hour basis, who because of age, mental disability or other reasons, live in a supervised residential environment that provides personal care services.  Condition 1 - The occupants are capable of responding to an emergency situation without physical assistance from staff. 

Condition 2 - This occupancy condition shall include buildings in which there are any persons receiving custodial care who require limited verbal or physical assistance while responding to an emergency situation to complete building evacuation. 

This occupancy classification will include but not limited to alcohol and drug centers, assisted living facilities, congregate care facilities, group homes, halfway houses, residential board and care facilities, and social rehabilitation facilities.

A facility housing not less than six and not more than 16 persons receiving custodial care shall be classified as a group R-4 occupancy. A facility with five or less persons receiving custodial care shall be classified as a group R-3 or shall comply with the International Residential Code (IRC) provided in automatic sprinkler system is installed in accordance with sections 903.3.1.3 or section P2904 of the International Residential Code (IRC).

Group I-2:  Used for medical, surgical, psychiatric, nursing or custodial care on a 24 hour basis of more than 5 persons who are not capable of self-preservation.  

Condition 1 - This occupancy condition shall include facilities that provide nursing and medical care but do not provide emergency care, surgery, obstetrics or in-patient stabilization units for psychiatric or detoxification, including but not limited to nursing homes and foster care facilities. 

Condition 2 - This occupancy classification shall include facilities that provide nursing and medical care and could provide emergency care, surgery, obstetrics or inpatient stabilization units for psychiatric or detoxification, including but not limited to hospitals. 

Less than five people shall be considered a Group R-3. This group shall include but not be limited to the following: foster care facilities, detoxification facilities, hospitals, nursing homes, and psychiatric hospitals.

Group I-3:  Is inhabited by more than five persons who are under restraint or security and is occupied by persons who are generally incapable of self-preservation due to security measures not under the occupant's control.

Condition 1 - Group I-2 classification shall include buildings in which free movement is allowed from sleeping areas, and other spaces where access or occupancy is permitted, to the exterior via means of egress without restraint. A condition one facility is permitted to be constructed as group R.

Condition 2 - Group I-2 shall include buildings in which free movement is allowed from sleeping areas and any other occupied smoke compartment to one or more other smoke compartments. Egress to the exterior is impeded by locked exits.

Condition 3 - Group I-2 shall include buildings in which free movement is allowed within individual smoke compartments, such as within a residential unit composed of individual sleeping units and group activity spaces, where egress is impeded by remote controlled release of means of egress from such a smoke compartment to another smoke compartment.

Condition 4 - Group I-2 shall include buildings in which free movement is restricted from an occupied space. Remote controlled release is provided to permit movement from sleeping units, activity spaces and other occupied areas within the smoke compartment to another smoke compartment.

Condition 5 - Group I-2 shall include buildings in which free movement is restricted from an occupied space. Staff controlled manual release is provided to permit movement from sleeping units, activity spaces and other occupied areas within the smoke compartment to another smoke compartment.

Group I-4:  Includes buildings or structures occupied by more than 5 persons of any age who receive custodial care for fewer than 24 hours per day by persons other than parents or guardians. (Adult Day Care or Child Day Care). This group shall include but is not limited to the following: adult day care, and child day care.

Section 308.5.1 - A child day care facility that provides care for more than 5 but not more than 100 children ages two and a half years or less, where the rooms in which the children are cared for are located on a level of exit discharge serving such rooms and each of these child care rooms has an exit door directly to the exterior, shall be classified as a group E occupancy.

Section 308.5.2 - Rooms and areas located within places of religious warship that provide care during religious functions shall be classified as part of the primary occupancy.

Section 308.5.3 - A facility having five or less persons receiving custodial care shall be classified as part of the primary occupancy.

Section 308.5.4 - A facility such as above within a dwelling unit and having five or less persons receiving custodial care shall be classified as a group R-3 occupancy or shall comply with the International Residential Code (IRC).

Click here to find out what fire alarm equipment is required for Group I Occupancy.

Mercantile Group M Occupancy:  

The use of a building or structure or a portion thereof for the display and sale of gods and involves stocks of goods. This occupancy shall include but not limited to the following: department stores, drug stores, markets, greenhouses for display and sale of plants that provide public access, motor fuel dispensing facilities, retail or wholesale stores, and sales rooms.

Click here to find out what fire alarm equipment is required for Group M Occupancy.

Residential Group R Occupancy:  

The use of a building or structure or a portion thereof, for sleeping purposes when not classified as an institutional Group I or when not regulated by the International Residential Code (IRC).

Group R-1:  Residential use for occupants that are primarily transient in nature. (Boarding houses with more than 10 occupants, congregate living facilities with more than 10 occupants Hotel, Motel, Boarding Home (transient), etc.)

Group R-2:  Residential use for occupants that are primarily permanent in nature. This includes but not limited to apartment houses, congregate living facilities for 16 or more non transient occupants, boarding houses that are non transient, convents, dormitories, fraternities and sororities, monasteries, hotels, live/work units, motels, and vacation timeshare properties.

Group R-3:  Residential use for occupants that are primarily permanent in nature which does not classify as Group R-1, R-2, R-4 or I. This includes but not limited to buildings that do not contain more than two dwelling units, care facilities that provide accommodations for five or less persons receiving care, congregate living facilities with 16 or less nontransient occupants, boarding houses that are nontransient, convents, dormitories, fraternities and sororities, monasteries, congregate living facilities for 10 or less transient occupants, boarding houses for transients, and lodging houses with five or less transient guest rooms and 10 or fewer transient occupants.

Care facilities for five or less people receiving care that are located within a single-family dwelling are allowed to comply with the International Residential Code (IRC) provided they are equipped with an automatic sprinkler system installed in accordance with sections 903.3.1.3 or section P2904 of the International Residential Code (IRC).

Group R-4:  Residential use for more than 5 but fewer than 16 occupants, excluding staff, who reside on a 24 hour basis in a supervised environment. 

Condition 1 - Group R-4 shall include buildings in which all persons receiving custodial care, without any assistance, are capable of responding to an emergency situation to complete building evacuation.

Condition 2 - Group R-4 shall include buildings in which there are any persons receiving custodial care who require a limited verbal or physical assistance while responding to an emergency situation to complete building evacuation.

Click here to find out what fire alarm equipment is required for Group R Occupancy.

Storage Group S Occupancy:  

The use of a building or structure or a portion thereof, for storage not classified as a hazardous occupancy.

Group S-1:  Moderate Hazard storage. Buildings occupied for storage uses that are not classified as group S-2 of combustible items.

Group S-2:  Low Hazard storage.  Occupancies include among others, buildings used for the storage of noncombustible materials such as products on wood pallets or in paper cartoons with or without single thickness divisions or in paper wrappings. Such products are permitted to have a negligible amount of plastic trim, such as knobs, handles or film wrapping. 

Public parking garages shall comply with section 406.4 and the additional requirements of section 406.5 for open parking garages or section 406.6 for enclosed parking garages.

Utility and Miscellaneous Group U Occupancy:  

The use of a building or structure or a portion thereof, not classified by any of the above occupancy groups. This occupancy can include but not limited to: agricultural buildings, aircraft hangars accessory to a one or two family residence, barns, carports, communication equipment structures with a gross floor area of less than 1500 square feet, fences more than seven feet in height, grain silos accessory to a residential occupancy, livestock shelters, private garages, retaining walls, sheds, stables, tanks, and towers.