The work letter should establish the specific sustainability standards and goals for the build-out, e.g., LEED®, E+C, and assure compliance with any applicable green building laws. Use of the LEED® checklist or other well defined metrics to establish the specific attributes required, can be an effective tool to minimize later disagreement. During build-out, a well qualified team of green design professionals should be in place to ensure the sustainability objectives are identified and achieved.