Heating, Ventilation and Cooling (HVAC) is part of the services that the base building provides to tenants and it is responsible for a significant part of the building’s energy consumption. Office tenants can influence heating and cooling choices by seeking green lease conditions and high performing buildings. Tenants’ energy savings activities that reduce waste heat, like lighting upgrades, also help to reduce the work of air-conditioners. A relationship with the building manager is essential to optimising heating and cooling for both energy savings and comfort indoors.