Atria create dramatic architectural spaces but pose significant fire engineering challenges. Smoke control, sprinkler design, and evacuation require specialist expertise.. Atrium Fire Engineering Atria — multi storey voids connecting floor levels — are architecturally desirable but fire engineering intensive. The open volume allows smoke to rise and spread to upper floors, potentially affecting escape routes on multiple levels simultaneously. The Fire Safety Problem Without adequate measures: Smoke from a ground floor fire fills the atrium within minutes Upper level escape routes become untenable before occupants can evacuate Fire can spread between floors via radiation across the void Structural elements exposed to the void are at risk Smoke Control Approaches Depressed Interface Method: Allow smoke to fill the atrium but keep the smoke layer above the highest occupied level Requires significant void volume or powerful smoke extract Natural: large roof vents (typically 5 10% of atrium floor area) Mechanical: high capacity extract fans (typically 30 100 m³/s) Void Edge Protection: Smoke barriers at void edge on each floor Channelling smoke away from upper level escape routes Can be physical (screens) or dynamic (air curtains) Must extend below the design smoke layer depth Sprinkler Interaction Sprinklers in atrium spaces are complex: Ceiling level sprinklers may be 20m+ above the fire — too high for effective operation Side wall sprinklers at each floor level around the void edge Drencher systems at void edge to prevent fire spread Sprinklers in adjoining spaces (the most likely fire location) BS 7974 Subsystem 3 The fire engineering approach for atria typically follows: Design fire — define a realistic fire scenario (location, HRR, growth rate) Smoke production — calculate mass flow rate using entrainment models Layer depth — predict smoke layer descent rate Tenability — assess visibility, temperature, and toxicity at escape route level Evacuation — ensure RSET < ASET with adequate safety factor CFD Modelling Atria almost always require CFD modelling because: Complex geometry prevents simple analytical calculations Multiple fire locations must be tested Wind effects on natural ventilation must be assessed Sprinkler cooling effects on smoke layer must be modelled For atrium fire engineering, contact us. Magnus Opifex SEVEN LTD — UK's Leading Fire Safety & Fire Engineering Consultancy 🌐 magnus opifex.co.uk 📞 +44 7486 691724 ✉️ office@magnus opifex.co.uk Founders: Nicoleta Vasile, Baroness of Brattleby — CEO, Lawyer and Barrister, Legal & Administrative Director Alina — Technical Director & Expert Fire Engineer (BEng) Head Office: Ealing Cross, 85 Uxbridge Road, London W5 5BW Magnus Opifex SEVEN LTD delivers engineering led fire engineering, fire risk assessments, CFD modelling, and building safety consultancy across the United Kingdom and internationally. With over 20 years of combined experience and a UK portfolio spanning healthcare, residential and infrastructure, we bring truly engineered solutions with a personal touch. © 2026 Magnus Opifex SEVEN LTD. All rights reserved.