Chapter 18.38


18.38.010    Purpose.

18.38.020    Affordable housing requirements in CBC overlay zone.

18.38.030    Locations of affordable housing incentive programs.

18.38.040    Modifications of development standards.

18.38.050    Affordable housing agreement.

18.38.060    Implementation provisions.

18.38.010 Purpose.

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 chapter is to:

A. Help achieve comprehensive plan goals of affordable housing;

B. Implement through regulations the responsibility of the city under state law to provide for housing opportunities for all economic segments of the community;

C. Preserve opportunities for affordable housing as the city continues to grow;

D. Create affordable housing opportunities as a result of increased development capacity in various zones of the city, including the CBC downtown zone;

E. 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. 2017-564 § 24; Ord. 2012-457 § 8).

18.38.020 Affordable housing requirements in CBC overlay zone.

A. For any development in the CBC overlay zone that includes residential units (e.g., multiple-family developments, mixed use developments), not less than 10 percent of the units shall be moderate income affordable housing units, unless altered through a developer agreement. The applicant will enter into an affordable housing agreement, and have occupancy requirements and affordability levels as defined in this chapter. 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 subsection (E) of this section.

B. Fractional Units. In the event a fractional affordable housing unit is required, payment in lieu is allowed for the fractional unit. The in-lieu payment shall be consistent with the provisions of subsection (E)(6) of this section.

C. Alternate Affordability Levels. An applicant may propose alternative affordability levels for the affordable housing units as shown in the following chart:

Affordability Level (as a Percent of Median Income)

Percent Affordable Units for Baseline Requirement

FAR Potential Incentive to Affordable Ratio*






4 to 1




3 to 1




2 to 1

*Pursuant to Chapter 18.36 NMC, General Provisions – Floor Area Ratio Incentives.

D. Modifications of Development Standards.

1. Projects that include affordable housing units, as defined in Chapter 18.06 NMC, shall provide one off-street parking space per affordable unit. Modifications may be requested pursuant to NMC 18.18.030, Computation of required off-street parking spaces.

2. Recreation Space. Affordable housing units shall provide recreation space for affordable units as specified in Chapter 18.14 NMC at 50 percent of the levels required for market rate units.

E. Alternative Compliance. The director may approve a request for satisfying all or part of the affordable housing as required by this chapter with alternative compliance methods if they meet the following requirements:

1. 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.

2. 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.

3. 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 CBC downtown zone.

4. Priority is for the project to be located within the CBC downtown zone. However, the director may approve a project located outside the CBC downtown zone if it can demonstrate the location has access to commercial uses, transit, and does not result in an undue concentration of affordable housing.

5. 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.

6. Cash payments in lieu of providing actual housing units may be proposed. The formula for alternative payments will be established by the director. The payment obligation will be established prior to issuance of any building permits for the project. Payment is required at time of issuance of the first building permit, other than for grading and shoring unless the developer can provide a form of surety acceptable to the city (e.g., bond). In no event will an in-lieu payment be paid later than temporary or permanent certificate of occupancy.

7. 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. 2017-564 § 24).

18.38.030 Locations of affordable housing incentive programs.

A. Residential Density Incentives. Residential density incentives (RDI) for affordable housing are allowed in R-1 through R-24 zones, unless the zone is located within the CBC overlay zone, and in the NB zone. Provisions related to the amount of RDI for affordable housing in these zones are defined in Chapter 18.34 NMC. Affordable housing units created through the provisions of Chapter 18.34 NMC shall also comply with the provisions of this chapter.

B. CBC Overlay Zone. Within the CBC overlay zone, provision of affordable housing is required pursuant to the provisions of NMC 18.38.020. Floor area ratio (FAR) incentives are available for providing affordable housing in the CBC overlay zone as defined in this chapter. Affordable housing units created through the provisions of Chapter 18.15 NMC shall also comply with the provisions of this chapter.

C. Cottage Housing Development. Within the cottage housing development as defined in Chapter 18.31 NMC, provision of affordable housing is required pursuant to the provisions of NMC 18.31.230. Affordable housing units created through the provisions of Chapter 18.31 NMC shall also comply with the provisions of this chapter. (Ord. 2017-564 § 24; Ord. 2012-457 § 8. Formerly 18.38.020).

18.38.040 Modifications of development standards.

An applicant may request a modification of the minimum required number of parking spaces pursuant to NMC 18.18.030. (Ord. 2017-564 § 24; Ord. 2012-457 § 8. Formerly 18.38.030).

18.38.050 Affordable housing 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 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. (Ord. 2017-564 § 24; Ord. 2012-457 § 8. Formerly 18.38.040).

18.38.060 Implementation provisions.

The following requirements shall be met for all affordable units created through any of the incentive programs referenced in NMC 18.38.030:

A. Duration. Affordable housing units that are provided under this section shall remain as affordable housing for a minimum of 50 years except, at the sole discretion of the city, approval may be for a shorter period so that federal underwriting standards are met. But in no case shall the time period be less than 30 years from the date of initial owner occupancy for ownership affordable housing units and for the life of the project for rental affordable housing units.

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:

1. 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.

2. 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.

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

4. 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.

5. 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 any design standards for the underlying zoning district. 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.

C. 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.

D. Monitoring and Fee. The city reserves the right to establish in the affordability agreement referred to in NMC 18.38.050 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.

E. Administrative Official. The director shall be responsible for administration of this chapter. The director may adopt administrative procedures for implementation of this section. (Ord. 2017-564 § 24; Ord. 2012-457 § 8. Formerly 18.38.050).