Car Park Fire Protection and the Electric Vehicle Risk

An enclosed car park carries three fire difficulties at once: a high fire load, limited smoke extraction and a freezing risk. The spread of electric vehicle charging has added a fourth.

Car park provisions in BYKHY

The regulation gives clear thresholds for car parks. The first decision is whether the car park is open or enclosed; most thresholds attach to enclosed car parks.

Article	Provision
60/1	A car park counts as open if its total opening to the outside exceeds 5% of the floor area; otherwise it is an enclosed car park. Where the openings are on two facades, they must be on opposite facades and each must exceed half of the required total opening.
60/1	Enclosed car parks with a total area above 600 m² must have an automatic sprinkler system, a fire hose cabinet system and fire brigade outlets.
96/2-c	Automatic sprinklers mandatory in enclosed car parks with a total area above 600 m² and in enclosed car parks where more than 10 vehicles are taken in by lift.
94/1-b-1	Fire hose cabinets mandatory in enclosed car parks with a total area above 600 m².
94/1-a-1	Fire brigade outlet connections in car parks with a floor area above 1000 m², located in protected spaces such as the escape stair or fire lobby.
60/2	A mechanical smoke extraction system is required in enclosed car parks with a total area above 2000 m²; it must be independent of the systems serving the rest of the building and provide at least 10 air changes per hour.
60/3	Enclosed car parks where vehicles are taken in by lift must have natural or mechanical ventilation.
60/4	Vehicles running on LPG or CNG may not enter enclosed car parks; the conditional LPG exception for shopping centre car parks is set out below.
24/2	Car park walls and floors have the properties of compartment walls.
Annex 4 (Ek-4)	No limit on the maximum compartment area for enclosed car parks.
72/2	Emergency lighting required in enclosed car parks.

Sprinkler design follows TS EN 12845 under Article 96/5.

LPG vehicles: the 2020 shopping centre exception

Under the sentence added to Article 60/4 by OG 04/11/2020-31294, LPG vehicles that comply with the legislation may enter the enclosed car parks of shopping centres within the scope of the Regulation on Shopping Centres (OG 26/02/2016-29636) if the car park meets the rules for "Type 1 - commercial car parks" in TS 9881, holds a TSE service competence certificate and the favourable opinion of the local fire service, and also:

• The authorities that issue business licences keep records of these car parks and inspect them, or have them inspected, every year (60/4-a).
• A sign of at least 90x60 cm bearing the TS 9881 conformity mark is posted at the vehicle entrance (60/4-b).
• Areas taking LPG vehicles may not be below the first basement level, and they and their entrances and exits are separate from those of other car parks (60/4-c).
• Ventilation and electrical installations are spark-proof (ex-proof); ventilation runs automatically from a detector for LPG accumulating at floor level and has the capacity to sweep the gas (60/4-ç).
• Floor drainage uses a suitably graded channel, no gratings, and trapped gullies at the discharge points (60/4-d).
• Only vehicles whose registration certificate states LPG and that hold a valid inspection may use these car parks; non-compliant LPG vehicles are refused (60/4-e).

The exception covers LPG only; the regulation gives no exception for CNG vehicles.

The core requirements

• Automatic suppression. Under BYKHY, sprinklers are mandatory in enclosed car parks with a total area above 600 m² and in enclosed car parks where more than 10 vehicles are taken in by lift (Article 96/2-c, 60/1). The hazard class is at least Ordinary Hazard 2: BYKHY Annex 1/B and TS EN 12845 Annex A classify car parks as OH2, and NFPA 13 also gives car parks as an OH2 example (A.4.3.3.2). Higher protection is assessed separately for mechanical car parks where vehicles are stacked.
• Smoke extraction. Mechanical smoke extraction is mandatory in enclosed car parks with a total area above 2000 m² (Article 60/2). A jet fan or ducted system aims at visibility and temperature control for both evacuation and firefighting, integrated with fire detection scenario by scenario.
• Drainage and interceptors. Floor falls, channels and an oil interceptor are needed for sprinkler water and vehicle fluids; the suppression design is not complete until drainage is solved.
• Freeze protection. A wet system can freeze in an open-sided or unheated car park, so a dry system or an antifreeze solution is needed.
• Escape routes and signage. Keeping pedestrian escape routes clear of vehicle manoeuvring areas is the most frequently overlooked issue in car parks.

What the electric vehicle risk changes

A lithium-ion battery fire differs from a petrol vehicle fire in three respects:

1. It is cooled, not extinguished. Thermal runaway produces its own oxygen, so conventional extinguishment does not stop the reaction. Water is used as a coolant to break propagation.
2. It lasts. Cooling can take hours, and the vehicle can reignite days later.
3. Gas release. The flammable and toxic gas mixture released during runaway accumulates in an enclosed car park and creates an explosion risk.

Those three differences produce three design consequences: extending the water supply duration, reviewing smoke and gas extraction capacity, and positioning the charging area.

Design checklist

Heading	Check
BYKHY thresholds	Open/enclosed test (5%), 600 m² (sprinklers, hose cabinets, fire brigade outlets), more than 10 vehicles by lift, 2000 m² (mechanical smoke extraction) checked?
Hazard class	At least Ordinary Hazard 2 (Annex 1/B) applied, and the need for higher protection in stacker or mechanical car parks assessed with the reasoning recorded?
Water supply duration	Reviewed with the EV risk in mind?
Smoke extraction	Tested against scenarios and integrated with detection?
Drainage	Can contaminated water be retained, and is the interceptor sized?
Freezing	Is the system type suited to the climate and car park type?
Charging area	Location, separation and removal access assessed?
Response plan	Long-duration cooling and reignition planned for?

Mechanical and stacker car parks

Car parks that stack vehicles above one another behave like storage racking: fire spreads vertically and ceiling sprinklers cannot reach the lower levels. NFPA 13-2025 permits sidewall sprinklers to be placed under each level of cars in these installations (10.3.2); where coverage under the cars is not possible, ceiling protection for systems with two cars stacked vertically is designed to Extra Hazard Group 2 (A.10.3.2, A.4.3.4.2). Ceiling protection designed to the ordinary car park class (OH2) alone is inadequate.

Under BYKHY, sprinklers are mandatory in enclosed car parks where more than 10 vehicles are taken in by lift, regardless of area (Article 96/2-c), and enclosed car parks where vehicles are taken in by lift must have natural or mechanical ventilation (Article 60/3).

Frequently Asked Questions

Are sprinklers mandatory in an enclosed car park?

Yes in enclosed car parks with a total area above 600 m² and in enclosed car parks where more than 10 vehicles are taken in by lift (BYKHY Article 96/2-c). Article 60/1 also makes fire hose cabinets and fire brigade outlets mandatory in enclosed car parks above 600 m². A car park whose opening to the outside exceeds 5% of the floor area counts as open.

How does the electric vehicle risk change the design?

It calls for a longer water supply duration, a review of gas and smoke extraction capacity, and charging areas positioned away from escape routes in a zone vehicles can be removed from.

Why is drainage critical in a car park?

Uncontrolled spread of sprinkler water and vehicle fluids both hampers firefighting and creates an environmental risk. Floor falls, channels and an oil interceptor are part of the design.

Are ceiling sprinklers enough in a mechanical car park?

Not with an ordinary car park (OH2) design. Stacked vehicles behave like storage racking: fire spreads vertically and ceiling water cannot reach the lower levels. Either sprinklers are placed under the cars at each level (NFPA 13-2025, 10.3.2) or, where that is not possible, ceiling protection for systems with two cars stacked vertically is designed to Extra Hazard Group 2 (A.10.3.2, A.4.3.4.2).

Can LPG vehicles enter an enclosed car park?

As a rule, no: vehicles running on LPG or CNG may not enter enclosed car parks (Article 60/4). Since the 2020 amendment, LPG vehicles may enter only the enclosed car parks of shopping centres within the scope of the Regulation on Shopping Centres, subject to conditions such as TS 9881 Type 1 rules, a TSE service competence certificate, fire service approval, no location below the first basement, separate entrances and exits, and ex-proof installations.

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