Sun Tower

Yakima, WA

With spectacular views of downtown Yakima and the valley, this residence provides seniors a welcoming community where they can maintain their independence in dignity and comfort


  • High-efficiency lighting design
  • Variable refrigerant flow (VRF) system in l1 common area
  • High-efficiency package terminal air conditioner (PTAC) in residential units
  • Low flow plumbing fixtures
  • Condensing domestic hot water heaters
  • Low-e double-panes vinyl windows in residential units

Sun Tower is a 95,000 sq. ft., twelve-story affordable senior living and assistance community located in the sunny heart of Washington State. Its 141 studio and one-bedroom apartments provide both residential and assisted living, enabling low-income seniors 62 and older to maintain their independence in dignity and comfort. The developer and architect team, inspired by some of the work presented on the success of the Green Communities Project, engaged O’Brien360 to help identify and prioritize energy and water efficiency updates as part of a major renovation. O’Brien360 completed a site assessment, including a robust sampling of ventilation and water fixture flow rates. We compiled two years of energy, water, and solid waste utility bills and developed degree-day

regression models to identify the heating, cooling, and baseload energy flows. Using the site measurements and energy monitoring data from past projects, we further refined the models to identify other end-use flows, such as elevators and hot water heating. The analysis gave the owners and design team a better understanding of how utility dollars were being spent and was used to prioritize retrofit funds. In addition, O’Brien360’s design review led to identifying a suitable heat pump HVAC replacement option, available for a negligible additional cost over the electric resistance option.