Self-Storage Fire Protection: NFPA 13 and the Turkish BYKHY

Standard: NFPA 13 (2025), NFPA 1, BYKHY
Hazard class: Ordinary Hazard Group 2 (OH2) and above
Reading time: 8 min

What Is Self-Storage and Why Is the Fire Risk Different?

Self-storage facilities consist of independent storage units that customers rent for their personal belongings. They differ from conventional storage facilities in three basic ways:

1. The stored goods are unknown — The customer is not obliged to declare what is stored. One unit may hold a sofa set, another a set of tyres, another paint tins or an electric scooter. The fire load cannot be calculated in advance.
2. 24/7 access — Customers can come at any hour to drop off or collect belongings. This means automatic door locks, motion sensors and uncontrolled people traffic.
3. Corridor layout — Units open onto narrow corridors. Smoke exhaust and escape routes must be designed differently from standard storage facilities.

The self-storage market in Turkey has grown quickly over the last five years, and several operators have opened dozens of branches, mainly in Istanbul and Ankara. However, the Turkish Regulation on Fire Protection of Buildings (BYKHY) contains no specific section on self-storage. At the same time, under BYKHY Article 96/5 the sprinkler system design must follow TS EN 12845; the NFPA 13 values in this article are for comparison and good practice.

NFPA 13 Design Criteria

Hazard Class

NFPA 13 gives no separate hazard class for self-storage. The standard's OH2 definition (NFPA 13-2025, 4.3.3.2): occupancies where the quantity and combustibility of contents are moderate to high; stockpiles of contents with moderate heat release rates do not exceed 3.7 m (12 ft), and stockpiles with high heat release rates do not exceed 2.4 m (8 ft). Under this definition, units storing personal belongings are designed as at least Ordinary Hazard Group 2 (OH2). The design point for OH2 is a density of 8.1 mm/min (0.20 gpm/ft2) over a 140 m2 (1,500 ft2) design area (NFPA 13-2025 Table 19.2.3.1.1; the 2025 edition has no density/area curves and gives a single point for each hazard class).

Because the contents are unknown, however, most design engineers prefer to design to Extra Hazard Group 1 (EH1). Decision matrix:

At Least One Sprinkler per Unit

Under the IBC (International Building Code), every storage unit must have at least one sprinkler; this rule applies regardless of wall height or construction type. NFPA 13 has no rule specific to self-storage units; layout follows the standard's general spacing rules.

Rule of thumb: in ordinary hazard, the protection area of a standard sprinkler is at most 12.1 m2 (130 ft2), the spacing between sprinklers at most 4.6 m (15 ft), and the distance to a wall cannot exceed half that spacing, i.e. 2.3 m (NFPA 13-2025 Table 10.2.4.2.1(b), 10.2.6.2.1). A unit larger than 12.1 m2, or with a side longer than 4.6 m, needs a second sprinkler.

Storage Height Limit

With standard pendent and upright sprinklers, at least 450 mm (18 in.) of clearance must remain between the deflector and the top of storage (NFPA 13-2025, 10.2.9.1); storage height in self-storage facilities is limited accordingly. In typical practice:

• Ceiling height: 3.0–4.5 m
• Maximum storage height: 2.7–4.0 m
• Distance between sprinkler deflector and top of storage: ≥ 450 mm

Many facilities cover the tops of units with an open-grid ceiling or wire mesh to stop customers stacking too high. This does not obstruct the sprinkler discharge pattern but physically limits the storage height.

Sprinkler Type Selection

Water Supply and Pump Sizing

Water Demand Calculation

Basic water demand for an OH2 design:

Q = Design density × Design area + Hose allowance

Q = 8.1 × 139 + 950 ≈ 1,126 + 950 ≈ 2,080 L/min

Hose allowance: per NFPA 13-2025 Table 19.2.3.1.2, a total of 250 gpm (≈ 950 L/min) for ordinary hazard; the inside hose allowance (0/50/100 gpm) is included in this total.

For an EH1 design:

Q = 12.2 × 232 + 1,900 ≈ 2,830 + 1,900 ≈ 4,730 L/min

Hose allowance: per the same table, a total of 500 gpm (≈ 1,900 L/min) for extra hazard.

Water Tank Capacity

Under BYKHY Article 92, the water tank capacity is calculated from the simultaneous water demand of the sprinkler system plus the hose cabinets plus the hydrants. Typical for self-storage:

• Duration: per NFPA 13-2025 Table 19.2.3.1.2, 60–90 min for ordinary hazard and 90–120 min for extra hazard
• Example volume: for OH2, 2,080 L/min × 60 min ≈ 125 m3; for EH1, 4,730 L/min × 90 min ≈ 425 m3 (the hydrant and hose cabinet allowances of BYKHY Article 92 are added separately)

Pump Selection

The pump is selected for the system demand from the hydraulic calculation:

• Type: electric motor driven (easy site access)
• Flow: system demand + 10% margin
• Pressure: system pressure from the hydraulic calculation (including pipe friction and elevation losses) + safety margin

Compartmentation and Passive Protection

Fire Compartments

Self-storage facilities follow one of two fire compartment strategies:

Approach 1: Full compartmentation

• Walls between units fire-resisting (at least 60 minutes)
• Corridor walls 120 minutes
• Maximum compartment area: 1,115 m2 (12,000 ft2), in a single-storey building without corridors and with a 1-hour fire barrier between each unit

Approach 2: Sprinkler protection + compartmentation

• Sprinklers and 60-minute walls
• Maximum compartment area: depends on the building height class under BYKHY

Smoke Control

Because of the corridor layout, smoke control is critical:

• Long and dead-end corridors: smoke exhaust is assessed specifically for the project (BYKHY Articles 85-88)
• Escape route: at least 2 independent exits
• Smoke detectors: in corridors and common areas, per the NFPA 72 placement rules
• If there is an atrium: NFPA 92 smoke management applies

Fire Alarm and Detection System

System Selection

An addressable fire alarm system is recommended for self-storage facilities. Putting a smoke detector in every unit is not practical (customers' belongings can obstruct it), but detectors should be provided in corridors and common areas.

24/7 Access and Alarm Management

Customers in self-storage facilities have 24/7 access. This means the fire alarm system has to work in two modes:

1. Working hours (building occupied): alarm → sounder + strobe + automatic notification to the fire brigade
2. Out of hours (building empty): alarm → sounder + strobe + automatic notification to the fire brigade + notification to the security company

BYKHY Compliance

Although BYKHY contains no rules specific to self-storage, the following articles apply:

• Article 96: automatic sprinkler system
• Articles 94–95: hose cabinets and hydrant system
• Article 24: fire compartments
• Articles 85–88: smoke control

Most self-storage facilities in Turkey are assessed as "storage" for fire protection purposes and are subject to the BYKHY requirements for storage.

Example Projects in Turkey

Facilities of Multi-Branch Operators

The facilities of multi-branch self-storage operators in Istanbul and Ankara are usually set up by converting basements or industrial-type buildings. This creates extra difficulties for fire protection:

• Basement: smoke exhaust and water drainage need to be strengthened separately
• Industrial building conversion: ceiling height and structural fire resistance need to be checked
• Corridor width: under BYKHY Article 33/1, an escape route cannot be narrower than the calculated value or 80 cm, and cannot be less than 110 cm if used as a hall or corridor; in high-rise buildings it cannot be less than 120 cm (Article 33/2)

Compliance Difficulties

The biggest problems of self-storage facilities in Turkey:

1. Regulatory gap — BYKHY does not recognise self-storage; whether it is "storage" or "workplace" is unclear
2. Lack of insurance — Are customers' belongings insured? Who pays after a fire?
3. Inspection — Periodic maintenance (NFPA 25) is generally not carried out
4. Customer education — Even with a contract banning combustibles, enforcing it is difficult

Practical Design Checklist

• ☐ Hazard class determined (OH2 minimum, EH1 recommended)
• ☐ At least 1 sprinkler placed in every unit
• ☐ Physical barrier for the storage height limit (≥ 450 mm below the deflector)
• ☐ Water demand calculated (L/min)
• ☐ Water tank capacity ≥ 60 minutes (OH2) / 90 minutes (EH1)
• ☐ Corridor smoke exhaust assessed specifically for the project
• ☐ Addressable fire alarm system (corridors + common areas)
• ☐ At least 2 independent escape routes
• ☐ Hose cabinet layout per BYKHY Article 94 (hose reach distance)
• ☐ Fire department connection (FDC) at the building entrance, accessible
• ☐ Clause banning combustibles in the customer contract
• ☐ NFPA 25 periodic maintenance plan ready

References

1. NFPA 13 — Standard for the Installation of Sprinkler Systems, 2025 Edition. National Fire Protection Association. https://www.nfpa.org/codes-and-standards/nfpa-13/standard-development/13

2. NFPA 1 — Fire Code, 2024 Edition. National Fire Protection Association. https://www.nfpa.org/codes-and-standards/nfpa-1/standard-development/1

3. NFPA 72 — National Fire Alarm and Signaling Code, 2025 Edition. National Fire Protection Association. https://www.nfpa.org/codes-and-standards/nfpa-72/standard-development/72

4. NFPA 92 — Standard for Smoke Control Systems, 2024 Edition. National Fire Protection Association. https://www.nfpa.org/codes-and-standards/nfpa-92/standard-development/92

5. International Code Council — International Building Code (IBC), Section 903 (Automatic Sprinkler Systems) and Section 422 (Self-Service Storage Facility). https://codes.iccsafe.org/s/IBC2024P1

6. Turkish Regulation on Fire Protection of Buildings (Binaların Yangından Korunması Hakkında Yönetmelik, BYKHY) — Official Gazette 19/12/2007-26735. Amendments: OG 09/09/2009-27344; OG 05/04/2012-28255; OG 09/07/2015-29411; Council of Ministers Decision 2017/10459 of 14/06/2017 (in force 29/06/2017); Council of Ministers Decision 2018/11347 of 05/02/2018 (in force 15/03/2018); OG 04/11/2020-31294 (Presidential Decision 3167); OG 20/11/2021-31665 (Presidential Decision 4825); OG 01/07/2025-32943 (Presidential Decision 10026). Articles used: 24, 33, 85-88, 92, 94, 95, 96. https://www.mevzuat.gov.tr/MevzuatMetin/21.5.200712937.pdf

7. Self Storage Association (SSA) — Industry Standards and Best Practices. https://www.selfstorage.org

8. SFPE — Society of Fire Protection Engineers. Fire Protection Engineering Resources. https://www.sfpe.org

9. FM Global — Property Loss Prevention Data Sheets. https://www.fmglobal.com/research-and-resources/fm-global-data-sheets

Frequently Asked Questions

What is the minimum sprinkler hazard class for self-storage facilities?

NFPA 13 does not define a separate hazard class for self-storage; based on the OH2 definition in 4.3.3.2, these facilities are designed as at least Ordinary Hazard Group 2 (OH2). Because the contents are unknown, however, most engineers prefer to design to Extra Hazard Group 1 (EH1).

Does every self-storage unit need a sprinkler?

Yes. Under the IBC, every storage unit must have at least one sprinkler; this rule applies regardless of wall height or construction type. Under the general spacing rules of NFPA 13, in ordinary hazard one sprinkler protects at most 12.1 m2 and can be at most 2.3 m from a wall; units exceeding these limits need a second sprinkler.

Does BYKHY contain specific rules for self-storage?

No. BYKHY does not contain a specific section for self-storage. Self-storage facilities in Turkey are usually assessed as storage and are subject to the BYKHY requirements for storage (Articles 24, 85-88, 94, 95, 96).

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