Chapter 21B.75


21B.75.010    Purpose and intent.

21B.75.020    Basic density provisions.

21B.75.030    Modifications to dimensional standards.

21B.75.040    Alternative compliance.

21B.75.050    Implementation provisions.

21B.75.060    Definitions.

21B.75.010 Purpose and intent.

The incentives and regulations offered in this chapter are used by the City as one means of meeting its commitment to encourage housing affordable to all economic groups, and to meet its regional share of affordable housing requirements. The purpose of this section is to: (1) implement through regulations the responsibility of the City under state law to provide for housing opportunities for all economic segments of the community, (2) help address the shortage of housing in the City for persons of low- and moderate-income, (3) preserve land for affordable housing as the City continues to grow, (4) promote development of housing that would not otherwise be built in the City, (5) create affordable housing opportunities as a result of increased development capacity in the Town Center planning area, (6) offer additional incentives to encourage construction of affordable housing units in Town Center; and (7) encourage developments that include affordable housing and that combine local incentives provided by the City with resources available from other public and private sources. (Ord. O2010-293 § 1 (Att. A))

21B.75.020 Basic density provisions.

(1) Baseline Affordable Housing. In any residential development (e.g., multiple-family developments (rental or ownership), single-family subdivisions, mixed-use developments) not less than 10 percent of the allocated residential density dwelling units pursuant to SMC 21B.25.030 must be affordable housing units. The affordable housing units will have occupancy requirements and affordability levels as defined in SMC 21B.75.060. For any site, this requirement applies to the residential units provided up to the base number of allowed units. No additional residential or commercial density beyond the base number of allowed units will be provided to meet this 10 percent affordable unit requirement. Those projects providing additional affordable units may receive additional density as provided in subsection (3) of this section, Residential Bonus Units/Additional Affordable Housing, and as provided for in SMC 21B.25.040. (Note that in some cases, applicants may receive additional residential unit allocations based on TDR purchases and/or site amenities.) This program is intended to increase the actual supply of affordable housing, so the primary objective is to obtain housing units within the development in preference to an alternative approach, except as otherwise provided for in SMC 21B.75.040.

(2) Affordable Housing Units and Allocated Residential Density. Required affordable housing units pursuant to subsection (1) of this section shall be counted as one-half a dwelling unit for the purpose of calculating allocated residential density pursuant to SMC 21B.25.030. For example, a residential development that requires six affordable housing units would calculate the affordable housing units to be equivalent to three dwelling units for the purpose of calculating allocated residential density pursuant to SMC 21B.25.030. Affordable housing units built for the purposes of increasing site density above the allocated residential density shall be counted as one dwelling unit for the purposes of calculating maximum residential density pursuant to SMC 21B.25.030.

(3) Residential Bonus Units/Additional Affordable Housing. The Town Center Plan includes the allocation of 344 residential bonus units (427 total units once the discounted affordable housing units are added per subsection (2) of this section) specified in SMC 21B.25.040. Allocation of residential bonus units is based on the following criteria:

An individual project can receive three residential bonus units for each affordable housing unit provided above the minimum 10 percent required pursuant to this section. The affordable housing units will have occupancy requirements and affordability levels as defined in SMC 21B.25.040.

Example: If a property has a base density of 50 units, and an applicant requested nine residential bonus units, three of the bonus residential units would have to be affordable units. The development would have a total of 59 units of which eight would be affordable units (five affordable units of the base 50 units, plus three of the nine bonus residential units).

(4) Alternative Calculation of Affordability. An applicant may propose alternative affordability levels for the affordable housing units. The percentage of required affordable units and the ratio of bonus units (or bonus floor area) per affordable housing unit for alternative affordability levels will be as follows:

Affordability Level

Percent Affordable Units for Baseline Requirement

Residential Bonus Units to Affordable Units Ratio

50% of median income


3.3 to 1

60% of median income


3.2 to 1

70% of median income


3.1 to 1

80% of median income


3 to 1

Note: Depending on the level of affordability provided, the affordable housing units may not be eligible for the impact fee waivers described in SMC Title 14A.

(5) Rounding. For developments with more than 10 residential units, the number of required affordable housing units is determined by rounding fractional numbers up to the nearest whole number from one-half.

(6) Minimum Threshold. For any residential development consisting of less than 10 units, the affordability requirements may be satisfied through the payment to the City of an in-lieu fee.

(a) Amount. The in-lieu fee to be paid for each affordable dwelling unit shall be determined by the director and shall equal an amount sufficient to create an amount of affordable housing equal to or greater than what would have otherwise been provided if the affordable housing had been provided on site.

(b) Timing of Payment. In lieu-fees shall be paid at the time a building permit is issued for the development.

(c) Alternative to Cash. At the discretion of the City council (or director), where a developer is authorized to pay a fee in lieu of development, an irrevocable dedication of land or other nonmonetary contribution of a value not less than the sum of the otherwise required in-lieu fee may be accepted as an alternative to paying the in-lieu fee if it is determined that the nonmonetary contribution will be effectual in furthering the goals and policies of the housing element and this chapter. The valuation of any land offered in lieu shall be determined by an (MAI) appraisal made by an agent agreed upon by the City. Costs associated with the appraisal shall be borne by the developer.

(d) Deposit of Fees. All in-lieu fees collected hereunder shall be deposited in a housing trust fund. The fund shall be administered by the City and shall be used only for the purpose of providing funding assistance for the provision of affordable housing and reasonable costs of administration consistent with the policies and programs contained in the housing element of the general plan.

(e) Use of Fees. The location of affordable housing funded wholly or in part with cash payments shall be prioritized in the following order: (i) within the Sammamish Town Center; (ii) in the City within one-half mile of transit service; and (iii) if no local project, resources may be redirected to ARCH Housing Trust Fund. (Ord. O2010-293 § 1 (Att. A))

21B.75.030 Modifications to dimensional standards.

The following requirements of the Town Center development code may be modified to accommodate residential bonus units. These modifications may not be used to accommodate the units resulting from the base density:

(1) Parking Requirement. An applicant may request a modification of the minimum required number of parking spaces by providing a study that substantiates parking demand can be met with a reduced parking requirement in a manner consistent with the goals and policies of the applicable regional transportation plan. Said study shall be prepared by a qualified professional transportation planner or engineer approved by the director.

(2) Structure Height. Maximum height for structures containing affordable housing units may be increased by one story in the TC-A and TC-B zones consistent with setback requirements in Chapter 21B.30 SMC. Maximum structure height may not be modified through this provision for any portion of a structure that is adjoining a TC-C, D or E zone. (Ord. O2010-293 § 1 (Att. A))

21B.75.040 Alternative compliance.

(1) General. The director may approve a request for satisfying all or part of the affordable housing requirements with alternative compliance methods if they meet the following requirements.

(a) The project proponent may propose an off-site alternative, and must demonstrate that any alternative compliance method achieves a result equal to or better than providing affordable housing on site.

(b) Affordable housing units provided through the alternative compliance method must be based on providing the same type of units as the units in the project which give rise to the requirement.

(c) Off-site affordable housing units may be provided off site if the location chosen does not lead to undue concentration of affordable housing in any particular area of the Town Center.

(d) Priority is for the project to be located within the Town Center Plan Area. However, the director may approve a project located outside the Town Center Plan Area if it can demonstrate the location has access to commercial uses, transit, and does not result in an undue concentration of affordable housing.

(2) Alternative Compliance Requirements.

(a) The proposal by the project proponent must demonstrate that the affordable units provided off site will be completed before or within the same time period as the development generating the affordable housing requirement, or such other assurances as approved by the director.

(b) Alternative compliance is not allowed for affordable housing associated with residential bonus units.

(c) Any single-family development containing between 10 and 14 units may meet their affordable housing requirement through the alternative compliance provisions of this section, so long as their proposal meets all the other provisions of this section.

(d) Applications for alternative compliance shall be submitted at the time of application, and must be approved prior to issuance of any building permit. The proposal must describe a specific location, type, and amount of affordable housing and how and when it will be developed. Any proposal for providing off-site affordable housing must also address the timing for providing the off-site housing, which, unless otherwise approved by the City, shall be built simultaneously with or prior to the construction of housing for the subject property. For projects approved for off-site affordable housing, there will be a recorded agreement on both the “sending” property and the “receiving” property. The covenant on the sending site will be released once the affordable housing is completed on the receiving property. (Ord. O2010-293 § 1 (Att. A))

21B.75.050 Implementation provisions.

(1) Applicability. These requirements and incentives in this chapter are applicable in the Town Center zones.

(2) Affordable Unit Requirements. The following requirements shall be met for all affordable units:

(a) Duration. Housing shall serve only income-eligible households for a minimum period of 50 years from the later of the date when the affordability agreement between the housing owner and the City, as referenced in this section, is recorded, or the date when the affordable housing becomes available for occupancy as determined by the City.

(b) Designation of Affordable Housing Units. Prior to the issuance of any permit(s), the City shall review and approve the location and unit mix of the affordable housing units consistent with the following standards:

(i) Location. The location of the affordable housing units shall be approved by the City, with the intent that they generally be intermingled with all other dwelling units in the development.

(ii) Tenure. The tenure of the affordable housing units (ownership or rental) shall be the same as the tenure for the rest of the housing units in the development.

(iii) Size (Bedroom). The affordable housing units shall consist of a range of number of bedrooms that is comparable to units in the overall development.

(iv) Size (Square Footage). The size of the affordable housing units, if smaller than the other units with the same number of bedrooms in the development, must be approved by the director. If there is a proposal that the affordable units be smaller than the market rate units, in no case shall the affordable housing units be less than 500 square feet for a studio unit, 600 square feet for a one bedroom unit, 800 square feet for a two bedroom unit, or 1,000 square feet for a three bedroom unit.

(c) Design. The exterior design of the affordable housing units must be compatible and comparable with the rest of the dwelling units in the development and must comply with design standards specified in Chapter 21B.30 SMC. The interior finish and quality of construction of the affordable housing units shall at a minimum be comparable to entry level rental or ownership housing in the City.

(d) Timing/Phasing. The affordable housing units shall be available for occupancy in a time frame comparable to the availability of the rest of the dwelling units in the development.

(3) Affordability Agreement. Prior to issuing any building permit, an agreement in a form approved by the director that addresses price restrictions, homebuyer or tenant qualifications, phasing of construction, monitoring of affordability, duration of affordability, and any other applicable topics of the affordable housing units shall be recorded with the King County department of records and elections. This agreement shall be a covenant running with the land and shall be binding on the assigns, heirs and successors of the applicant. The City may agree, at its sole discretion, to subordinate any affordable housing regulatory agreement for the purpose of enabling the owner to obtain financing for development of the property.

(4) Monitoring and Fee. The City reserves the right to establish in the affordability agreement referred to in this section monitoring fees for the affordable housing unit, which can be adjusted over time to account for inflation. The purpose of any monitoring fee is for the review and processing of documents to maintain compliance with income and affordability restrictions of the affordability agreement.

(5) Administrative Official. The director shall be responsible for administration of this section. The director may adopt administrative procedures for implementation of this section. (Ord. O2010-293 § 1 (Att. A))

21B.75.060 Definitions.

(1) “Affordable housing unit” means housing reserved for occupancy by eligible households and affordable to moderate-income households, adjusted for household size, and no more than 30 percent of the monthly household income is paid for monthly housing expenses.

Pursuant to the authority of RCW 36.70A.540, the City finds that the higher income levels specified in the definition of “affordable housing” in this section, rather than those stated in the definition of “low-income households” in RCW 36.70A.540, are needed to address local housing market conditions in the City.

(2) “Moderate-income household” means a household whose gross income of all permanent household members over the age of 18 is equal to or less than 80 percent of the King County median income, adjusted for household size.

(3) “Low-income household” means a household whose gross income of all permanent household members over the age of 18 is equal to or less than 50 percent of the King County median income, adjusted for household size.

(4) “Median income” means the median income for the Seattle MSA as most recently determined by the Secretary of Housing and Urban Development under Section 8(f)(3) of the United States Housing Act of 1937, as amended, or if programs under said Section 8(f)(3) are terminated, median income determined under the method used by the Secretary prior to such termination. (ARCH) In the event that HUD no longer publishes median income figures for the Seattle MSA or King County, the City may use any other method for determining the King County median income, adjusted for household size. (Ord. O2010-293 § 1 (Att. A))