Infill Development: Opportunities and Constraints, King County, Washington. Case Study: Fid-Bau Portal

Infill Development: Opportunities and Constraints, King County, Washington. Case Study

D. Brett

This report covers the results of a case study of infill development opportunities undertaken in King County, Wash. Infill development can be broadly defined as the use of sites that have remained vacant in otherwise builtup areas. These sites can range in size from a vacant lot of 1,000 square feet to large tracts of over 100 acres. Findings in this report are based on inspections and secondary data collected for a stratified systematic sample of 167 vacant infill parcels (68 in the City of Seattle and 99 in the suburbs). Interviews were conducted with owners of 129 of these properties to assess regional market and governmental concerns affecting infill feasibility. The study found that fully serviced infill land in King County could meet a significant portion of the county's growth - related land needs over the next 10 years; that the size of vacant tax parcels in the sample ranged from just under 2,000 square feet to 36 acres (with a mean size of just under 2 acres); that 52 percent of the sampled properties had vacant adjacent land and 60 percent were found to have other vacant parcels on the same block; and that environmental limitations on infill potential were not so extensive as is commonly believed. Neighborhood maintenance levels in the vicinity of vacant sites were rated good or fair for over 95 percent of all sampled infill parcels. The study also found that 75 percent of the owners of the sampled vacant infill parcels in King County who were interviewed were not in the real estate business. Moreover, government agencies owned 16 percent of the sampled infill properties, primarily within the City of Seattle. Nearly half of the sampled parcels' owners were not planning to make their property available for development in the next 5 years, increasing the pressure for further conversion of land from rural to urban uses at the fringe. Results of cost comparisons for developing standard townhouse units for three typical sites are discussed. Figures, tables, maps, and footnotes are provided.