Recognising that space is a critical resource for buildings, and in an effort to allow higher capacity bike parking options, Standards Australia introduced the concept of 'Dynamic' bike racks in AS2890.3 (2015). The general AS2890.3 (2015) spacing requirement for the width of a bicycle parking space is 500mm. Dynamic racks allow parked bikes to be moved in order to create the required 500mm space for locking and parking movements. Compliant Dynamic racks can reduce the effective width of a bicycle parking space to 400mm - allowing for a 20% capacity increase in a given space. Compliant 2-tier racks that provided Dynamic elements on both the upper and lower tiers, can increase capacity in a given space by over 100%.