BSD opinion on fire protection of private stair in three-storey dwellings containing whole house ventilation systems under STAS

Following an "alternative" approach submitted by Cala Homes Ltd in association with a STAS application, BSD have issued an opinion on compliance with Mandatory Standard 2.9 for the fire enclosure of a private stair in a three-storey house in relation to air transfer throughout the house by the MHVR ventilation system - see BSD Opinion