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The timeline below outlines key points in the history of the King County TDR program.

1988: Early TDR program developed

In September 1988, the King County Council directed the Department of Natural Resources and Parks to develop a TDR program for implementation through a community planning process.

  • A “Transfer of Development Credits” (TDC) program was established, which allowed density transfers only into unincorporated urban residential areas of King County.
  • This early program allowed both urban and rural sending sites.
  • The code provided for a 1:1 transfer ratio.
  • Sending sites were required to subtract unbuildable acreage prior calculating TDCs, e.g. wetlands, streams, steep slopes.
  • Sending sites in the R-1 zone were initially only allocated 1 TDC per acre (now 4 TDRs/acre); and rural receiving sites were allowed in RA-2.5 and RA-5 zones.

Between 1988 and 1995 only one transfer was completed.

1996: KC Council Funds development TDR Receiving Area Plan

In March 1996, the KC Council appropriated $125,000 to match $125,000 from WA State Legislature to fund a “Transfer of Development Rights Receiving Area Plan” which included a market analysis and public process. The King County Comprehensive Plan policies called for the TDR mechanism to allow rural to rural transfers as well.

The Receiving Area Plan process resulted in these findings in November 1997:

  • Market analyses indicated a need for a 2:1 transfer ratio to encourage transfers from rural areas into urban areas
  • Identified a need to establish a “regional” TDR approach whereby cities would be compelled to participate and the need to pursue a pilot program to with a city within King County to work out the model
  • Identified the need to establish a TDR Bank to help finance transactions county-wide

1998:  Final TDR Receiving Area Plan completed

In 1998, the King County Executive transmitted to King County Council the Final Receiving Area Plan necessary to revise existing TDR Code and implement an updated TDR program.

1999: KC Council appropriates $1.5 million to KC TDR Bank to buy development rights

In 1999, the King County Council appropriated $1.5 million to TDR program to purchase and “deposit” credits in the King County TDR Bank. King County Council also:

  • Authorized a series of pilot projects focused on reaching agreements with cities to accept additional density
  • Dedicated $500,000 as amenities to urban communities willing to accept rural density credits

2000: TDR Bank fund and policies established

In April 2000, the King County Council approved code language that established the TDR Bank fund and adopted policies and procedures for the administration of pilot TDR Bank.

2001: TDR Bank “pilot” project converted to permanent status in KC Code

In July 2001, the KC Council converted the pilot program into permanent status and established much of the TDR code language in current code. Major changes included:

  • Changed name from Transfer of Development “Credits” to “Rights”
  • Focused efforts into cities, with TDR Bank and amenity funding language
  • Established a 2:1 transfer ratio for “rural” TDRs (i.e. 2 additional urban units per 1 rural unit transferred)
  • Removed language that netted out un-buildable sensitive areas
  • Removed urban sending sites (except for properties with R-1 zoning)
  • Changed the R-1 zoning allocation to 4 “urban” TDRs per acre.
  • Allowed properties in the Agricultural (A) zone to transfer 1 TDR per 5 acres rather than at density allowed by zoning.

Also in 2001, Interlocal agreements were signed with Seattle and Issaquah.

2003 to the present …

In the last 5 – 6 years the program as shown meaningful market results and significant land protection.

2008:  New policies to bolster demand and improve supply-side incentives

In 2008, King County Council adopted the new comp plan with host of new TDR policies and Code language, which are reflected in the content of this site, and the current King County Code. Some of these policies include:

  • Use of TDRs to help meet greenhouse gas emissions targets for new development projects
  • Use of TDRs to satisfy traffic concurrency requirements for development in rural areas
  • Higher transfer ratios in RA-10 zones

For questions about the TDR Program, please contact Michael Murphy, TDR Program Manager, or Anne-Gigi Chan, Land Conservation Project Manager, King County WLRD Rural and Regional Services Section.