At a time when gas is becoming constrained, utilities are restricting new gas hookups, and electrification is the trend, a model has emerged to significantly reduce energy use, as well as dramatically improve IAQ and comfort in buildings. This session will explore replacing existing packaged rooftop units (RTUs) at end of life with Very High Efficiency (VHE) heat or energy recovery ventilation as the dedicated outside air system (DOAS), and heat pumps for heating and cooling. This results in significant energy savings, improved IAQ and health of the building, and happy, comfortable occupants. The session will include several case studies with data demonstrating the range of benefits for the building owners and occupants, as well as the ROI upon installation and commissioning of these systems.