Receiving Site Information
Transfer of Development Rights
Once development rights from sending sites become certified, the sending site is protected from future development, and the TDRs are available to use at receiving sites, which are parcels of land located where the existing services and infrastructure can accommodate additional growth - typically in urban areas. TDRs may be used in several ways at qualified receiving sites:
- To increase density (typically 150%) above what is allowed by the base zoning.
- To increase Floor Area Ratios (typically %150) above what is allowed by base zoning.
- To meet traffic concurrency requirements (if used in the same travelshed as the sending site)
- To allow construction of larger accessory dwelling units in the Rural Area
- satisfy carbon offset requirements
Basic criteria for receiving sites are outlined below. The TDR Code has the detailed criteria for receiving sites.
Areas qualified to receive TDRs include:
- Unincorporated King County urban areas zoned R-4 through R-48, NB, CB, RB, or O.
- Incorporated cities where allowed by the local jurisdiction.
- Rural areas zoned RA-2.5 if TDRs originate in a Rural Forest Focus Area and all of the following conditions are also met:
- The site is served by a domestic Group A public water service;
- The site is within ¼ mile of an existing predominant pattern of lot sizes smaller than 5 acres;
- The project will not adversely impact regionally or locally significant resource or environmentally sensitive areas; and
- The project will not require public services and facilities to be extended in order to create or encourage a new pattern of smaller lots
The following areas cannot receive TDRs under any circumstances:
- Properties on Vashon or Maury Islands,
- Properties within the Rural Forest Focus Area, or
- Properties within the outer boundaries of the Noise Remedy Area identified by Sea-Tac International Airport
Allowed increases in density using TDRs
Zone |
Description |
Base Density (du/ac)* |
Maximum Density (du/ac) |
RA-2.5 |
Rural Area |
0.2 |
0.4** |
R-4 |
Residential |
4 |
6 |
R-6 |
Residential |
6 |
9 |
R-8 |
Residential |
8 |
12 |
R-12 |
Residential |
12 |
18 |
R-18 |
Residential |
18 |
27 |
R-24 |
Residential |
24 |
36 |
R-48 |
Residential |
48 |
72 |
NB |
Neighborhood Business |
8 |
12 |
CB |
Community Business |
18 |
24 |
RB |
Regional Business |
36 |
48 |
O |
Office |
36 |
48 |
| * du/ac = dwelling units per acre (see density) ** Additional conditions apply as outlined above | |||
Using development rights on a receiving parcel
When you apply to King County for a residential building permit or apply to subdivide land, you will need to supply proof that you own the development rights. Proof of ownership consists of a TDR certificate, or a TDR letter of intent in your name, or a signed option to purchase development rights from someone who owns a certificate or a letter of intent. Proof of ownership is sufficient to start the King County review process on your development application. (See additional information about permits from DDES).
Before receiving a building permit or final plat or short plat recording, you will need to deliver to King County:
- TDR certificates in your name for the number of development rights you wish to apply at the site, and
- a TDR extinguishment document.
These documents show that you own the development rights and that they have been used and cannot be used again on another project. (See also TDR Code.) The process for using TDRs to increase density may differ among different local jurisdictions.
For TDR transactions within unincorporated King County, each Rural TDR allows two additional units in urban receiving areas; each Urban TDR allows one additional unit. When transfers from unincorporated King County into an incorporated city are allowed through an interlocal agreement, transfer ratios are defined in the terms of the agreement and/or the code of the incorporated city.
There are other, non-density uses for TDRs as well, including the use of TDRs to satisfy "traffic concurrency" requirements for subdivisions, and use of TDRs to help meet greenhouse gas targets associated with development projects.