3400 at CityLine is a new LEED Gold commercial office building along US 75 Central Expressway at Renner Road in Richardson, Texas. The five-story 300,000 sf building features 60,000 sf floor plates and a two-story atrium connecting the north and south entrances. Best-in-class finishes and unmatched access and visibility distinguish this project among surrounding office developments. The building includes floor-to-ceiling glass with 10-foot ceiling heights, a premium deli and lounge area, fitness center, and a 40,000-sf exterior courtyard. Cost-effective tilt-wall panels are clad in spandrel glass to provide a high-end curtainwall-like appearance. An adjoining pre-cast parking structure provides 400 spaces.
In addition to the design features and amenities, 3400 CityLine is the first Wired Certified ground-up development in Texas. Wired Certification is a commercial real estate rating system that empowers landlords to understand, improve, and promote their buildings’ digital infrastructure.
DBR provided mechanical, electrical, and plumbing engineering services. Electrical systems included the use of LED lighting throughout the building interior as well as the site. Transformers were specified as high-efficiency harmonic mitigating transformers (HMTs) which exceed Department of Energy 2016 requirements. Energy monitoring has been provided in the form of building metering and lighting submetering, including monitoring and alarm if the lighting load exceeds a specified value, which was initially set to 1.0 Watts/square foot. Site and landscape lighting have been designed and evaluated to minimize light pollution and light trespass.
At 3400 Cityline the design team utilized a combination of envelope enhancements, high-efficiency HVAC systems, and energy-efficient lighting and controls to deliver an estimated 23.9% energy cost savings compared to the ASHRAE 90.1 baseline. HVAC equipment included high-efficiency packaged water-cooled air handling units and parallel fan-powered terminal units with ECM fan motors. All air handling unit supply fans, cooling tower fans, and HVAC pumps were provided with variable frequency drives to ensure maximum efficiency at part load conditions. A waterside economizer was incorporated into the design to increase the efficiency of the cooling system when outdoor conditions permit. Demand control ventilation was incorporated for each air handling system to reduce the energy required for cooling and heating of ventilation air during off-peak occupancy, while maintaining indoor carbon monoxide concentrations at acceptable levels.