Approved Document B (paragraphs 3.50 – 3.53) specifies that AOVs should open on smoke detection and meet the specified free area and this could technically be achieved by automating an existing window.
The standard applying to natural ventilators that are part of a smoke and heat evacuation system (SHEV) is BS EN 12101-2 Smoke and heat control systems – Natural smoke and heat exhaust ventilators and it is recommended by the Smoke Control Association that all AOVs should comply with this standard.
We offer both EN12101-2 compliant Louvred Windows as well as EN12101-2 Compliant Casement Windows.