skip to main content

Sustainable building

Envision, then build

To offer a suggestion or report an error on the Natural Resources and Parks' website, please contact Fred Bentler, webmaster.

Transfer of Development Rights - TDR - in King County, Washington State

Transfer of Development Rights bank



King County operates the King County TDR Bank, which has three key roles:

(1) Facilitate the private TDR market by bridging the time gap between willing sellers and buyers of TDRs;

(2) Act as a revolving fund for continued land protection through buying, holding, and selling TDRs (proceeds from TDR sales are used for future land protection); and

(3) Catalyze city-county TDR agreements by strategically acquiring development rights from high priority conservation rural / resource lands in the County that are of compelling interest for specific cities to see protected.

The TDR Bank was established in 1999 with an appropriation by the Metropolitan King County Council of $1.5 million to purchase TDRs and continues to play an important role in the King TDR Program. The primary function of the Bank is to facilitate the market in transferable development rights by engaging in high conservation priority transactions to open new markets for private TDR participants in cities that partner with King County. The remainder of this page covers several topics related to the King County TDR Bank:

TDR bank transaction history

Since establishment in 1999, the Bank has been involved in only eight TDR transactions – six purchases and two sales. This represents about 10% of all transactions in King County’s TDR program. The Bank applied the initial funding and secured supplemental grant funding in the six separate purchases to acquire a total of 1,218 TDRs. The bank has sold 49 TDRs in two separate transactions, recouping $1.33 million of the initial capital investment.

As of August 2011, the King County TDR Bank has 1,169 TDRs available for sale at a variety of prices, and from a variety of high conservation priority locations.

The following is a list of the Bank’s purchases and sales of TDRs, and the respective TDR sale prices.

TDR Bank Purchases

Sugarloaf Mountain (2001)
Sugarloaf Mountain is in southern King County roughly five miles east of Maple Valley in the Cedar River watershed (see map). After development rights were transferred to the Bank, King County purchased the property and continues to manage the land as working forest. (Learn more).

Acres protected:  256 acres
Number of TDRs purchased:  56
TDRs available for sale:  7


Ames Lake Forest

Ames Lake Forest (2002)

Ames Lake Forest is just west of the City of Carnation (west of the river and up the hill) and adjacent to King County’s Tolt-MacDonald Park. Together, the Ames Lake Forest and Tolt-Macdonald Park comprise more than 750 acres of permanently-protected forest adjacent to the Snoqualmie River (see map). The Ames Lake Forest is in private ownership and managed as working forest.

Acres protected:  444 acres
Number of TDRs purchased:  88
TDRs available for sale:  88

Snoqualmie Tree Farm (2004):
Forest Sending Area
The transfer of development rights from the Snoqualmie Tree Farm represents the single largest TDR deal nationally. Nearly 90,000 acres (about 140 square miles) just 20 miles from Seattle are forever protected as private working forest (see map).

Acres protected:  89,500 acres
Number of TDRs purchased:  990
TDRs available for sale:  990


Raging River / Fruit Growers Supply Co. (2009)

The Fruit Growers property comprises 4,373 forested acres at the headwaters of the Raging River – which provides benefits to fish and wildlife and helps reduce flooding for residents downstream in the Snoqualmie Valley (see map). To purchase the development rights from the property, King County used TDR Bank funds that resulted from the sale of TDR Bank-owned TDRs from Sugarloaf Mountain to developers of Olive 8 and Aspira Towers (see below). The Fruit Growers transaction represents the first complete revolution of funds through the TDR Bank since its inception.

Acres protected:  4,373 acres
Number of TDRs purchased:  60
TDRs available for sale:  60

Huschle Farm (2010)
Nature’s Last Stand, the farm owned and operated by John Huschle, Anna Davidson and their children, is a source of local organic food for area farmers markets. The Huschles had farmed the land for several years and wanted to buy the land, but couldn’t afford it. When the King County TDR Bank bought the TDRs, the value of the property was reduced enough so the Huschles could buy it and keep farming (see map).

Acres protected:  23 acres
Number of TDRs purchased:  3
TDRs available for sale:  3


Camp Sealth (2011)

Camp Sealth, a recreational and environmental education camp run by Campfire USA, has hosted tens of thousands of youth campers from the region Uncle Wigglebottom's Cabin at Camp Sealthsince opening in 1921. In the TDR deal, Campfire USA received a payment from the Bank for development rights which will helped the organization financially at a critical point in time. As a result, one mile of pristine Puget Sound shoreline on southwest Vashon Island is forever protected from development. (See map).

Acres protected:  101 acres
Number of TDRs purchased:  21
TDRs available for sale:  21





Bonomi Farm (2012)

The Bonomi Farm is located along Issaquah-Hobart Road in the heart of the Issaquah Creek basin and has been farmed by the Bonomi family for over 80 years. The transfer of development rights from this 125-acre property will preserve both active farmland and ecological habitat, including important chinook salmon spawning areas where Carey and Holder Creeks join to become Issaquah Creek. The King County TDR Bank will sell these development rights and revolve the funds for additional and future preservation along Issaquah Creek. These development rights are available for use in the City of Issaquah per the terms of the interlocal agreement between King County and Issaquah.

Acres Protected:   124.88 acres
Number of TDRs purchased:  24
TDRs available for sale:  24

Jubilee Farm (2012)

Jubilee Farm is located in the Snoqualmie Valley Agricultural Production District, about two and one half miles northeast of Fall City. With the transfer of development rights from 107 of its 210 acres, this property will now be protected in its entirety, as the remainder is enrolled in King County’s Farmland Protection Program. All 210 acres will forever remain organic farmland due to additional protections of a third easement purchased by the PCC Farmland Trust.

This transaction represents the first partnership of its kind with a private entity (PCC Farmland Trust) to preserve working farmland as organic farmland. This is the second transaction in the TDR Program’s initiative to buy development rights from active farms which supply local food to farmers markets.

 Acres Protected:  107.74 acres by TDR (additional 102.24 by FPP)
 Number of TDRs purchased:  13
 TDRs available for sale:  13

TDR Bank Sales

 The following properties have purchased TDRs from the Bank to achieve additional square footage of floor area in the project:

Olive-8 Building

Olive 8 is a LEED (Leadership in Energy and Environmental Design) Silver building which includes 231 condominiums, a health club and spa, and the Hyatt at Olive 8, a full-service luxury hotel. By using KC Bank TDRs from Sugarloaf Mountain, the developer was able to add 62,000 square feet of floor area to the project (55 additional units).


 Location:   Denny Triangle in downtown Seattle
 Developer Name:  R.C. Hedreen
 TDRs purchased:  31
 Amount of additional development capacity:  62,000 square feet (2,000 sf/TDR)



Aspira Building ; Keller CMS development Aspira Tower

The Aspira tower is a 37 Story apartment building with 326 units and a mix of market rate & affordable units. TDRs purchased from the KC TDR Bank allowed the developer to add 36,000 square feet to the project using TDRs from Sugarloaf
Mountain (60 additional units). 


 Location:  Denny Triangle in downtown Seattle 
 Developer Name:  Keller CMS
 TDRs purchased:  18
 Amount of additional development capacity:  36,000 square feet (2,000 sf/TDR)


Options to buy TDRs

In addition to direct TDR sales, the Bank is offering potential buyers options to buy TDRs. This way developers can, with a minimal outlay of capital, lock in a certain number of TDRs at a certain price for a specified length of time. This is especially valuable for development projects inside cities following passage of the new Tax increment Financing / TDR bill passed by the State Legislature and signed into law by the Governor in 2011 (SB 5253). In addition the King County TDR Bank can develop creative extended purchase and sale agreements with prospective buyers to ensure reduced developer risk and minimize up-front outlays of capital for TDR purchases.

Please contact Darren Greve. for more information about options to buy TDRs from the Bank and SB 5253.


Revenue-share with cities

 To open new markets for TDRs inside cities, the Bank can, depending on the city-county arrangement, enter into a revenue share agreement with the city. Under such an agreement the county provides the city with a portion of the proceeds it receives from sale of TDRs used for increased density inside the city. The funds provided to the city can be used for infrastructure improvements, creation of parks/open space, and streetscapes etc. inside the city.

In this way Bank dollars are used as amenity funds to help facilitate development right sales by assisting cities with infrastructure improvements needed to accommodate the extra density. Before amenity funds may be spent in a city, an interlocal agreement must be in place between the city and the county.

Development rights purchased from the TDR bank can only be used on receiving sites in urban unincorporated King County or incorporated cities. An interlocal agreement must be in place between King County and a city before TDR Bank development rights may be transferred to a development project within the city. As of August 2011, King County has interlocal agreements in place with the following cities: Bellevue, Issaquah, and Sammamish.

TDRs from sending sites must also meet any additional criteria specified in the particular interlocal agreement before the rights may be applied to a development project. For example, a particular interlocal agreement may specify that the city will only accept development rights from a specific area of rural King County that was of compelling interest to the City to see protected. Therefore, not all of the TDRs in the bank would be suitable for a project in a particular city.

For questions about TDR Program please contact Darren Greve, TDR Program Manager, King County WLRD Rural and Regional Services Section.