The purpose of this report is to examine the cost of incorporating sustainable design features into affordable housing projects in the cities of Seattle and Portland. The report includes both an analysis of the overall construction costs for green-rated and standard affordable housing projects, and a narrative summary of the key findings arising from the interviews with the projects’ participants. The report also includes a review of current funding-related building requirements and standard building practices in the cities of Seattle and Portland as they affect affordable housing, to identify green elements that are required or typically incorporated into buildings, regardless of a project's sustainability goals.