23.48.225

A. Base and maximum height limits 1. In zones listed below in this subsection 23.48.225.A.1, the applicable height limit for portions of a structure that contain non-residential and live-work uses is shown as the first figure after the zone designation and the base height limit for portions of a structure in residential use is shown as the first figure following the "/". The third figure shown is the maximum residential height limit. Except as stated in Section 23.48.025 , the base residential height limit is the applicable height limit for portions of a structure in residential use if the structure does not gain extra residential floor area under the provisions of Chapter 23.58A , and the maximum residential height limit is the height limit for portions of a structure in residential use if the structure includes extra floor area under the provisions of Chapter 23.58A : SM-SLU 100/65-145 SM-SLU 85/65-160 SM-SLU 175/85-280 SM-SLU 240/125-440 2. In the SM-SLU 85/65-160 zone on the blocks bounded by Valley Street, Mercer Street, Westlake Avenue North, and Fairview Avenue North, hotel use is permitted above 85 feet in height and is subject to the same provisions as residential use exceeding the base height limit for residential use, provided that all development standards that apply to a residential tower also apply to the hotel use, including the provisions of Section 23.48.221 for gaining extra residential floor area. 3. In the SM-SLU 85-280 zone, except as stated in subsections 23.48.225.C and 23.48.225.F, the base height limit is the applicable height limit for portions of a structure if the structure does not gain extra residential floor area under the provisions of Chapter 23.58A , and the maximum residential height limit is the height limit for portions of a structure in residential use if the structure includes extra residential floor area under the provisions of Chapter 23.58A , and if the structure complies with the standards for residential tower development in this Chapter 23.48 . 4. In the SM-SLU 100/95 zone, the maximum height for portions of a structure in non-residential or live-work use is 100 feet and the maximum height limit for portions of a structure in residential use is 95 feet. 5. In the SM-SLU 145 zone, the maximum height for all uses is 145 feet. B. Height limits in the SM-SLU/R 65/95 zone 1. New structures occupied only by non-residential uses are subject to a height limit of 65 feet. 2. Structures occupied only by residential uses and mixed-use structures with 60 percent or more of the structure's gross floor area in residential use are subject to a height limit of 95 feet. C. Additional height permitted in the SM-SLU 175/85-280 and SM-SLU 85-280 zones 1. Increases in the maximum height limit in the SM-SLU 175/85-280 and SM-SLU 85-280 zones. In the SM-SLU 175/85-280 and SM-SLU 85-280 zones a structure is allowed additional height of up to 30 percent above the maximum height limit for residential uses and, in the SM-SLU 175/85-280 zone, up to 20 percent above the height limit for non-residential uses, if all of the following conditions are met: a. The project includes an elementary school or a kindergarten through eighth grade school, which may include minimum space requirements for associated uses but not limited to academic core functions, child care, administrative offices, a library, maintenance facilities, food service, and specialty instruction space; b. Prior to issuance of a Master Use Permit, the applicant shall submit a letter to the Director from the school indicating that, based on the Master Use Permit plans, the school district has determined that the development could meet the operator's specifications; c. Prior to issuance of a building permit, the applicant shall submit a written certification by the operator to the Director that the operator's specifications have been met; d. The amount of floor area allowed to exceed the applicable height limit is equivalent to the amount of enclosed floor area on the lot in school use; e. The floor area added through the increase in height is subject to the development standards in Sections 23.48.235 and 23.48.240 that apply to structures that exceed the base height for residential use or the applicable podium height for non-residential uses; f. The floor area allowed to exceed the maximum residential height limit is not subject to the provisions for gaining extra residential floor area in Chapter 23.58A ; should the school use be discontinued, floor area gained through the provisions of this Section 23.48.225 shall be subject to the provisions of Chapter 23.58A ; and g. The allowances for rooftop features in subsection 23.48.025.B shall apply to the above structure height permitted under this subsection 23.48.225.C. 2. Additional height above the applicable height limit for portions of a structure that contain non-residential and live-work uses is permitted in the SM-SLU 175/85-280 zone at locations and under the conditions specified in Section 23.48.230 . 3. Extra residential floor area above the base height limit for residential use may be obtained as provided in Section 23.48.221 . 4. In the SM-SLU 175/85-280 zone, additional height above the applicable height limit, as described below, for up to two non-residential towers on one block is permitted if the tower or towers meet the following requirements. a. If a non-residential tower is developed, the tower closer to the eastern block front may be up to 190 feet in height. b. If a residential tower is developed, one residential tower on the northwest quadrant of the block may be up to 440 feet including a podium up to 125 feet. c. Rooftop features comply with subsection 23.48.025.C, which applies to the additional structure height permitted under this subsection 23.48.225.C.4. d. The additional height is to accommodate an additional increment of floor area provided in subsection 23.48.220.A.3.b. D. In the SM-SLU 175/85-280, SM-SLU 240/125-440, and SM-SLU 85-280 zones, an additional 10 feet in height is permitted above the otherwise applicable maximum height limit for residential uses for a structure that includes residential dwelling units that comply with all of the following conditions: 1. Unit number and size. The structure includes a minimum of ten dwelling units that each have a minimum area of 900 gross square feet and include three or more bedrooms; and 2. Amenity area. Each dwelling unit shall have access to an outdoor amenity area that is located on the same story as the dwelling unit and meets the following standards: a. The amenity area has a minimum area of 1300 square feet and a minimum horizontal dimension of 20 feet; and b. The amenity area must be common amenity area, except that up to 40% of the amenity area may be private provided that the private and common amenity area are continuous and are not separated by barriers more than 4 feet in height; and the private amenity areas are directly accessible from units meeting these requirements; and c. The common amenity area includes children's play equipment; and d. The common amenity area is located at or below a height of 85 feet. E. A proposal to build a structure greater than 85 feet in height in the SM-SLU 85/65-160 and SM-SLU 175/85-280 zones and located north of Mercer Street and West of Fairview Avenue within the South Lake Union Regional Center, requires the applicant to show that the proposed structure height will not physically obstruct use of the flight path shown on Map A for 23.48.225 or endanger aircraft operations. F. All non-exempt floor area and residential floor area located above the base height is considered extra floor area. Extra floor area may be obtained above the base height, up to the maximum height, through the provision of public amenities meeting the standards of Section 23.48.021 and Chapter 23.58A , except that floor area allowed through subsection 23.48.220.A.3.b is exempt from requirements to acquire regional development credits under 23.48.021.C.1.b and 23.48.021.C.2.b. In addition to the requirement to provide public amenities pursuant to Section 23.48.021 and Chapter 23.58A , the extra floor area may be obtained only if the project provides affordable housing and child care pursuant to subsection 23.48.021.C.1.a and 23.48.021.C.2.a. Map A for 23.48.225 South Lake Union Seaport Flight Corridor (Ord. 127375 , § 52, 2025; Ord. 127099 , § 27, 2024; Ord. 126157 , § 31, 2020; Ord. 125927 , § 3, 2019; Ord. 125603 , § 34, 2018; Ord. 125291 , § 6, 2017; Ord. 124883 , § 13, 2015.)