In May, 2007, VIA Architecture was engaged by Sound Transit to identify and examine potential environmental sustainability strategies that could be utilized in the design, construction, and operation of the U-Link line - a 3.1 mile extension to its Link Light Rail system. Since the original design of the Central Link in the late 1990's, awareness of environmentally responsible architecture and available technologies for fulfilling sustainability goals have grown exponentially. The U-Link therefore represented an opportunity to re-examine methods of designing and implementing a light rail system that take best advantage of energy conservation, stormwater management, judicious material selection, urban ecology, and many other aspects of environmental responsibility now given greater emphasis than in the initial project phases.

The scope of this study includes the following elements:

• Identification and examination of the system's basic components, including tunnel structures, stations, street-level plazas, at-grade headhouses, and train systems in order to understand their physical parameters and how opportunities for sustainable practices might arise from these.
• Analysis of different stages in the life of the project, from design and construction through to long-term operations, and identification of opportunities for sustainability strategies that could be employed during each of these stages.
• Research and examination of precedent sustainability strategies as employed by other transit agencies around the world, including policy implementation, design choices, construction practices, and operational initiatives.
• Research and examination of a variety of sustainability strategies applied to building projects in applications other than transit systems.
• Discussion with local agencies with regard to partnering and incentives to achieve shared environmental sustainability goals in the areas of energy conservation, stormwater management, urban ecology, daylighting, and potential cogeneration opportunities.

The report provided a summary of this research and provides recommendations to Sound Transit for the most promising and effective means of integrating environmental sustainability into the U-Link project.