AOV Smoke Vent Rooflight – Flat Roof Automatic Opening Vent, EN 12101-2 Certified, 8 Sizes

Most flat roof rooflights exist to let daylight in. This one exists to let smoke out. An AOV — automatic opening vent — rooflight sits in the roof like any other flat glazing unit until a fire alarm or smoke detection system triggers it, at which point the lid drives open to clear smoke from a stairwell, corridor or open-plan space below, buying occupants time to get out and keeping escape routes visible for the fire service. It's a life-safety component built into the roof, not an accessory bolted on afterwards, which is why it's specified into new-build and refurbishment projects on commercial, industrial and multi-occupancy residential buildings wherever Building Regulations Part B calls for smoke control.

Each unit is tested and certified to EN 12101-2, CE marked and UKCA certified, with a Class B non-fragility rating to ACR[M]001 so the glazing can be walked near safely during roof maintenance. Eight standard sizes cover everything from a single stairwell head to a larger open-plan smoke reservoir, and every size ships as a complete unit — dome/lid, drive mechanism and upstand kerb — ready to wire into a smoke control panel.

Key benefits

Genuine EN 12101-2 tested performance rather than a generic "vented rooflight" claim; Class B non-fragility glazing so the unit is safe to work near once installed; a standard size matrix that covers most stairwell and corridor applications without a bespoke order; and a construction that also functions as a normal opening rooflight for day-to-day ventilation and daylight, not just an emergency-only device.

Suitable applications

Stairwell and lobby smoke shafts on commercial and industrial buildings, corridor smoke ventilation on flats and multi-occupancy residential blocks, warehouse and retail smoke reservoirs, and any flat roof project where a fire strategy or Building Control condition specifies natural smoke ventilation. It is equally at home as day-to-day ventilation for a plant room or workshop that also needs an AOV for its fire strategy — one unit does both jobs.

Specification

Installation & ordering guidance

An AOV rooflight is part of a designed smoke control strategy, not a stand-alone purchase — confirm the required vent area, trigger logic and control panel with your fire engineer or Building Control before ordering, since the correct size and quantity depend on the space being protected, not on the roof opening alone. The unit is wired into a dedicated AOV/smoke control panel by a qualified electrician, and installation into the roof deck follows the same principles as our Electric Opening Flat Roof Skylight — a properly flashed, insulated upstand set into the waterproofing membrane. If you're also fitting standard daylight rooflights alongside the smoke vent on the same roof, our Frameless Flat Roof Skylight range and Polycarbonate Dome Rooflight use compatible upstand principles. For roof access to service the unit, see our Flat Roof Access Hatch.

FAQs

Do I need Building Control sign-off for an AOV rooflight?
Yes — smoke ventilation is a life-safety system, and the vent area, position and control strategy should be confirmed against your fire engineer's design or Building Control's requirements before you order, not decided from the roof opening size alone.

What certification does this unit actually carry?
It is tested and certified to EN 12101-2:2003, CE marked and UKCA certified, with Class B non-fragility glazing to ACR[M]001. We quote these as the manufacturer's stated certifications; always check the datasheet supplied with your order against your specific project requirements.

Can it be used as a normal opening rooflight day-to-day, not just in a fire event?
Yes. The powered actuator can be operated for everyday ventilation and purge as well as being triggered automatically by the smoke control panel in an alarm condition.

Does it come wired and ready to connect?
The unit ships with its actuator and drive mechanism fitted; final wiring into your smoke control panel is carried out on site by a qualified electrician as part of the wider fire strategy installation.

What roof build-up does it need?
It's supplied with a matching upstand kerb designed to be dressed into your flat roof waterproofing membrane, in the same way as a standard opening rooflight — insulated, properly flashed, and set above the finished roof level to shed water correctly.