Designing naturally ventilated deep, open-plan offices could improve occupants’ thermal comfort and
productivity and ensure energy reductions; however, this can be challenging when relying on façade only
openings. This research examines the ventilation performance sensitivity of atria, innovative façade openings
and interior layouts of open-plan offices, in order to identify optimal typologies. Different building typologies
are developed through a combination of various atria designs and configurations, with the effective use of highaspect-ratio (HAR) openings with a similar dimension to that of the floor-to-ceiling height, in either a mid-level
vertical (MLV) or high-level horizontal (HLH) orientation. Steady-state computational fluid dynamics (CFD)
simulations are performed to predict internal air flow and temperature distribution in a moderate climate and
water-bath modelling (WBM) experiments to validate the computational models. Results showed that MLV
provide superior cooling potential (up to 2.5oC reductions) and higher ventilations rates; despite, increasing
thermal gradients. Unobstructed atria with a horizontal profile similar to that of the building footprint also
performed well. Overall, façade opening design was shown to be the most influential design parameter. This
research has presented guidance based on reliable results to better equip building designers and architects in the
design of successful naturally ventilated deep, open-plan offices