Bennett Freehill were M&E Engineers for this major project which incorporates a new atrium (the Orientation Gallery) with lifts and feature staircases linking to the various levels in the museum and a new extension housing an enlarged restaurant and café with direct links to Botanic gardens. This was designed by Bennett Freehill as a low-energy passively controlled space, for more tolerant collection items and exhibits in display cases. The space is controlled within tolerance bands of 20ºC-24ºC and 40%-60% RH by a stack-driven natural ventilation system, underfloor heating and desiccant dehumidifier plant, all controlled via the BEMS. The design performance was validated by IES Apache thermal simulation and IES Microflo CFD modelling. Bennett Freehill also developed their own humidity modelling software to validate the humidity control systems and psychometrics of the space.