Guest rental suite for short term rental. Water submeters encourage and reward conservation by residents and have resulted in 20 - 30% reduction in water use in other buildings. Common-area HVAC equipment has “economizers” that switch to outside air for heating and cooling when temperatures permit doing so. Common-area HVAC has programmable thermostats with setbacks for off-peak periods. The laundry rooms have a separate heating and cooling system (rather than being heated and cooled by the hallway system). The dryers have a circuit sensor system that allows the system to operate at lower volume when the dryers are not in use. The leasing office and other separate common spaces use high-efficiency heat pumps instead of conventional electric fan coil units to reduce energy use. The work done to make a tighter building envelope allowed the HVAC engineers to design for less leakage and to reduce the amount of energy used for heating and cooling by approximately 10%. The hallways are slightly pressurized (more air being mechanically supplied than is being mechanically exhausted) so that the apartment exhaust fans do not pull outside air in through windows, electrical outlets, and other penetrations. The parking garage uses natural ventilation as much as possible. This is supplemented by exhaust fans that are controlled by carbon monoxide sensors and operate only when needed – providing fresh air in the garage while conserving energy.