The City of Seattle's Incentive Zoning Program allows developers to build bigger and taller when they support creation of new affordable housing. Both commercial and residential projects can participate in the program, which operates in certain zones targeted for increased development by the City. Seattle's Incentive Zoning Program is guided by SMC 23.58A of the Land Use Code. The Office of Housing and Department of Planning and Development coordinate on permit review for participating development projects.
Generally, residential developers opting to seek additional floor area in IZ-eligible zones with maximum height limits below 85 feet must dedicate a percentage of homes as affordable to households with incomes up to 80% of the area median income (AMI) for rental apartments or 100% of AMI for owner-occupied condominiums.
Residential Bonus: Extra floor area above the base height limit may be achieved for residential projects in exchange for contributing to affordable housing. Developers can either build affordable housing as part of their projects or, in certain zones, make a contribution of approximately $15 per gross square foot to the City to fund new affordable housing. The affordable housing is intended to primarily serve Seattle's moderate-wage workers. The Residential Bonus Program is available in moderate- and high-density zones in several neighborhoods.
Transferable Development Rights Potential (TDP): This option helps Seattle maintain a more variable scale of buildings in South Downtown and Multifamily Highrise zones by allowing undeveloped floor area to be moved from one site to another. Excess development rights from a certified TDP site can be sold to developers needing residential floor area beyond a base height or floor area ratio (FAR) limit. The proceeds of TDP sales are used for preservation of priority uses. The type of TDP that can be sent or received varies by zone and may include open space, Historic Landmarks, and South Downtown historic sites.
Extra non-residential floor area above the base floor area ratio (FAR) may be achieved for office, hotel or certain other building uses through non-residential bonus, transferable development rights (TDR), and on-site amenities. Non-residential and high-rise residential developers also have the option of making a cash contribution to the City for low-income housing. Twenty-five to forty percent of all additional floor area in high-rise zones (> 85') must be achieved through "non-housing" options (Landmark TDR/TDP, Open Space TDR/TDP, bonuses for on-site amenities).
Non-Residential Bonus: This incentive enables developers to achieve additional FAR in exchange for housing and childcare affordable to lower-wage workers. The housing and/or childcare can be provided by the developer or a cash contribution for housing and childcare facilities may be made to the City for those purposes. The non-residential bonus is currently available in certain Downtown, South Downtown and South Lake Union zones.
Transferable Development Rights (TDR): This option helps Seattle maintain a more variable scale of buildings in Downtown and South Downtown by allowing density to be moved from one site to another. Excess development rights from a certified TDR site can be sold to developers seeking non-residential floor area beyond a base floor area ratio (FAR). The proceeds of TDR sales are used for preservation of priority uses. The type of that can be sent or received varies by zone and may include within-block, housing, landmark housing, DMC housing, historic landmark, South Downtown historic, and open space.