As one of the fastest growing counties in Washington State, Pierce County’s open spaces and agricultural lands face development pressure. To better understand the trade-offs of developing the county’s rural areas, this report models two development scenarios, looking at the amount of land needed and associated costs of housing 100 people in an unincorporated, primarily rural, area versus in an incorporated, primarily urban, area. The report finds that development of rural areas has significantly higher impact in terms of ecosystem service costs; public benefit costs, such as clean air and water; and service utility costs, such as for public safety and utilities.