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.
The classic requirements
- Automatic suppression. Sprinklers are the typical requirement in enclosed car parks, with the hazard classification following the intensity of use and the type of car park.
- Smoke extraction. A jet fan or ducted system aims at visibility and temperature control for both evacuation and firefighting, integrated scenario by scenario with the fire detection.
- 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:
- 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.
- It lasts. Cooling can take hours, and the vehicle can reignite days later.
- 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.
Where charging points go is a fire decision. Charging points should not sit on an escape route, in front of a stair discharge or against a structural column; where possible they are grouped near an exit in an area vehicles can be removed from. That is an early decision to take together with the architecture.
Design checklist
| Heading | Check |
|---|---|
| Hazard class | Chosen for the car park type and intensity, 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. These installations need sprinklers at each level and an obstruction review; ceiling protection alone is inadequate.
Frequently Asked Questions
Are sprinklers mandatory in an enclosed car park?
Automatic suppression is the typical requirement in enclosed car parks, with the hazard classification following the type and intensity of use. The current regulation text governs the precise provision.
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?
No. Stacked vehicles behave like storage racking: fire spreads vertically and ceiling water cannot reach the lower levels. Sprinklers are needed at each level.
SprinkCalc — Fire Sprinkler Design Across Three Standards
SprinkCalc covers hazard classification, design density and area, K-factor selection, water demand and hydraulic calculations for NFPA 13, FM Global and BS EN 12845 in a single iOS app, and exports a professional PDF report.
Download SprinkCalc on the App Store
MEP Calc — 86+ Engineering Calculators
MEP Calc bundles 86+ engineering modules in one iOS app: 21 fire calculations plus heating, cooling, HVAC, plumbing, steam and natural gas.
Download MEP Calc on the App StoreThe Turkish Regulation on Fire Protection of Buildings (BYKHY) · NFPA 13 (2025) · NFPA 20 (2025) · BS EN 12845:2015+A1:2019 · FM Global Data Sheets. For article numbers, thresholds and exemptions, the current regulation text published in the Official Gazette governs.