Electric vehicle adoption is accelerating faster than fire safety guidance can keep up. With EV fires in enclosed car parks presenting extreme challenges, building owners need to act now.. The EV Revolution Meets Building Safety The UK has committed to ending the sale of new petrol and diesel cars by 2035. EV registrations are growing exponentially, and with them comes an urgent need to install charging infrastructure in existing buildings — particularly in basement and multi storey car parks. But these car parks were designed for petrol and diesel vehicles. The fire safety assumptions embedded in their design — ventilation rates, structural fire resistance, detection systems, and firefighting provisions — may not be adequate for the new risks posed by lithium ion battery fires. How EV Fires Differ An EV fire differs fundamentally from a conventional vehicle fire: Characteristic Conventional Vehicle Electric Vehicle Peak heat release rate 5 8 MW 6 10 MW Fire duration 30 60 minutes 60 90+ minutes Toxic gases CO, HCN CO, HCN + HF Re ignition risk Low High (hours/days) Water required 3,000 litres 10,000+ litres Explosion risk Fuel tank rupture Cell venting/BLEVE Current UK Guidance The primary guidance documents include: ADB Volume 2 — Approved Document B provisions for car parks BS 7346 7 — Smoke ventilation for car parks BS 9999 — General fire safety design code NFCC guidance on EV charging — Emerging guidance from fire services IStructE/CROSS alerts — Structural implications of EV fires However, these documents are struggling to keep pace with the speed of EV adoption. Many were written before the current generation of large battery EVs became common. Key Risk Areas 1. Structural Fire Resistance Car park structures are often designed with reduced fire resistance on the assumption that the fire load is limited and the structure is open sided: Open sided car parks may have no applied fire protection to structural elements Basement car parks typically require 60 120 minutes fire resistance EV fires burning for 90+ minutes may exceed the design assumptions The collapse of a car park structure due to an EV fire would be catastrophic 2. Ventilation Smoke from EV fires is more toxic than conventional vehicle fires HF gas is heavier than air and accumulates in basements Ventilation systems may need enhanced capacity for EV fire scenarios Natural ventilation in open sided car parks may be insufficient for the larger smoke volumes 3. Suppression Conventional sprinkler systems may not be effective against battery fires Water application to a lithium ion battery fire requires sustained cooling Deluge systems or enhanced sprinkler coverage may be appropriate Water run off from EV fire suppression is contaminated and must be managed 4. Detection Fast developing EV fires demand rapid detection Linear heat detection along parking rows Flame detection systems for faster response than smoke detection Gas detection for HF and hydrogen Recommendations for Building Owners Immediate actions: 1. Review fire risk assessment considering EV charging provision 2. Assess structural fire resistance against extended fire scenarios 3. Review ventilation system capacity 4. Consider enhanced detection in areas with EV charging 5. Engage with insurers regarding EV charging risks Medium term planning: 1. Develop an EV charging fire safety strategy 2. Consider sprinkler installation or upgrade 3. Install gas detection for basement car parks 4. Review emergency response plans with the fire service 5. Assess water supply adequacy for sustained firefighting Insurance Implications Insurers are increasingly focused on EV charging risks: Some policies now specifically exclude or limit EV fire cover Risk surveys are beginning to assess EV charging provisions Premium adjustments may apply for buildings with extensive EV charging Proactive risk management can help maintain favourable terms Building owners should engage early with their insurers when planning EV charging installations. For EV fire safety risk assessments and car park fire engineering, contact Magnus Opifex.