The government has laid new regulations for the fire safety of enclosed car parks, both new and existing. Get a detailed breakdown of the new rules on ventilation, suppression, and EV charging controls.. A New Era for Underground Car Park Fire Safety The Department for Levelling Up, Housing and Communities (DLUHC) has, as anticipated, introduced significant changes to fire safety regulations for enclosed car parks, marking a pivotal moment prompted by the escalating concerns surrounding electric vehicle (EV) fires. These amendments, brought into force in late 2026, address both new constructions and existing structures, aiming to mitigate the unique challenges posed by EV battery fires. This regulatory shift stems from considerable pressure exerted by fire and rescue services, insurers, and fire safety professionals, all grappling with the complexities of these high intensity, protracted incidents. The new framework will necessitate a comprehensive re evaluation of design, construction, and operational fire safety measures within these critical infrastructure assets. Regulatory Anchors: Amending Approved Documents B and S The core of these new provisions lies in the amendments to Approved Document B (Fire Safety) and Approved Document S (Infrastructure for Charging Electric Vehicles). These statutory instruments now explicitly incorporate requirements for enhanced fire safety provisions in enclosed car parks, particularly where EVs are present or likely to be charged. While the Building Safety Act 2022 (BSA 2022) provides an overarching framework for building safety, these specific amendments to the Approved Documents drill down into the practical application for car parks. The Regulatory Reform (Fire Safety) Order 2005 (RRO 2005) remains the cornerstone for operational fire safety and will now, by extension, encompass these new Approved Document requirements, placing greater onus on Responsible Persons to assess and manage the increased risks associated with EV charging. Ventilation: A Critical Rethink One of the most substantial changes revolves around ventilation systems. Traditional natural or mechanical ventilation systems in enclosed car parks are often inadequate to manage the intense heat and toxic fumes generated by EV battery fires. The updated Approved Document B now mandates significantly enhanced mechanical smoke and heat exhaust ventilation systems (SHEVS), designed to cope with higher heat release rates and prolonged smoke production. This will likely involve increased fan capacities, improved ductwork resistance, and more sophisticated control strategies to ensure effective smoke clearance and tenable conditions for firefighting operations. Compliance will draw heavily on guidance from BS 9991 and BS 9999, which will see further updates to align with these new performance demands for smoke control systems in such environments. New construction will require detailed computational fluid dynamics (CFD) modelling to demonstrate efficacy. Suppression Systems: Beyond Conventional Sprinklers The effectiveness of conventional sprinkler systems against EV battery fires has been a subject of intense debate. While not entirely dismissed, the new regulations necessitate a move towards more robust and, in some cases, specialised suppression strategies. For new enclosed car parks exceeding a certain footprint or housing a specified number of EV charging points, advanced suppression systems, such as enhanced sprinkler protection, water mist, or potentially even inert gas systems in highly specific zones, may be required. Existing car parks undergoing significant refurbishment or re purposing for EV charging will also face demands for upgrades. This shift reflects the understanding that sustained cooling is critical for controlling thermal runaway in EV batteries, a challenge traditional sprinkler systems may not always adequately address. The Fire Safety (England) Regulations 2022 (FS(E)R 2022) already reinforced the importance of robust fire safety measures, and now these specific car park requirements further elaborate that intent. EV Charging Point Controls: A Holistic Approach The amendments to Approved Document S directly address the design and installation of EV charging infrastructure. Key changes include requirements for: Isolation mechanisms: Automatic and manual isolation of power to charging points in the event of a fire. Zoning: Establishing clear zones for EV charging with appropriate fire separation. Monitoring systems: Integration of thermal monitoring or specific fire detection technologies capable of identifying early signs of battery thermal runaway. Proximity to exits and fire fighting access: Careful consideration of the placement of charging points to avoid impeding escape routes or hindering emergency services. These controls aim to reduce the likelihood of EV fires escalating and to provide firefighters with crucial time and information to manage incidents effectively. The recommenda