The McKinney project is a 3-story, 60,000 sf speculative office building with long facades facing southwest and northeast. The Weidt Group provided energy and daylighting consulting for this project that received a LEED Core and Shell Platinum rating. The new building performs 51.7 % better than ASHRAE 90.1-1999 requirements using the LEED Energy Cost Budget methodology.

The building façade was designed with overhangs and lightshelves to shade the glazing and provide glare-free daylight to the building interior. The building has a 14' floor-to-floor height with a 10’ ceiling, and a ground source heat pump provides cooling and heating with an under-floor displacement ventilation system. The ventilation is controlled by CO2 sensors, and the air stream includes a total heat recovery system. In addition, the entire southwest façade on all three floors is lined with private offices to block the low angle sun from penetrating into the rest of the building.

Energy-efficient lighting design strategies were modeled, including use of the Ergolight system that incorporates daylight sensors, occupancy sensors, and individual dimming. Since spaces will be leased to tenants, the lighting design and control strategies will be incorporated into the tenant improvement guidelines. The resulting savings for the building may be passed down to the tenants.

Additional energy saving features include the following.

• Low-E glazing with thermally broken aluminum frame
• R-50 roof insulation
• Overall wall insulation level of R-30
• Dimming daylighting controls in circulation areas
• Occupancy sensor control of lights in open offices, private offices, conference rooms, storage and restrooms
• Premium efficiency supply/return fan motors
• Premium efficiency pump motors
• Solar hot water panels for domestic hot water with a backup electric heater