Chapter 21A.75
RESIDENTIAL DENSITY INCENTIVES
Sections:
21A.75.010 Purpose.
21A.75.020 Permitted locations of residential density incentives.
21A.75.030 Maximum densities permitted through residential density incentive review.
21A.75.040 Public benefits and density incentives.
21A.75.050 Rules for calculating total permitted dwelling units.
21A.75.060 Review process.
21A.75.070 Minor adjustments in final site plans.
21A.75.080 Applicability of development standards.
21A.75.010 Purpose.
The purpose of this chapter is to provide density incentives to developers of residential lands in urban areas and rural activity centers, in exchange for public benefits to help achieve comprehensive plan goals of affordable housing, open space protection, and energy conservation, by:
(1) Defining in quantified terms the public benefits that can be used to earn density incentives;
(2) Providing rules and formulae for computing density incentives earned by each benefit;
(3) Providing a method to realize the development potential of sites containing unique features of size, topography, environmental features or shape; and
(4) Providing a review process to allow evaluation of proposed density increases and the public benefits offered to earn them, and to give the public opportunities to review and comment. (Ord. O99-29 § 1)
21A.75.020 Permitted locations of residential density incentives.
Residential density incentives (RDI) shall be used only on sites served by public sewers and only in the following zones:
(1) In R-4 through R-18 zones; and
(2) In NB, CB and O zones when part of a mixed use development. (Ord. O99-29 § 1)
21A.75.030 Maximum densities permitted through residential density incentive review.
The maximum density permitted through RDI review shall be 150 percent of the base density of the underlying zone of the development site or 200 percent of the base density for RDI proposals with 100 percent affordable units. (Ord. O99-29 § 1)
21A.75.040 Public benefits and density incentives.
(1) The public benefits eligible to earn increased densities, and the maximum incentive to be earned by each benefit, are set forth in subsection (6) of this section. The density incentive is expressed as additional bonus dwelling units (or fractions of dwelling units) earned per amount of public benefit provided.
(2) Bonus dwelling units may be earned through any combination of the listed public benefits.
(3) The guidelines for affordable housing bonuses including the establishment of rental levels, housing prices and asset limitations will be updated and adopted annually by the council in the comprehensive housing affordability strategy plan.
(4) Bonus dwelling units may also be earned and transferred to the project site through the transfer of density credit (TDC) process set forth in Chapter 21A.80 SMC, by providing any of the open space, or park site public benefits set forth in subsections (6)(2) or (6)(3) of this section on sites other than that of the RDI development.
(5) Residential development in R-4 through R-18 zones with property specific development standards requiring any public benefit enumerated in this chapter shall be eligible to earn bonus dwelling units as set forth in subsection (6) of this section when the public benefits provided exceed the basic development standards of this title. When a development is located in a special overlay district, bonus units may be earned if the development provides public benefits exceeding corresponding standards of the special district.
(6) The following are the public benefits eligible to earn density incentives through RDI review:
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BENEFIT |
DENSITY INCENTIVE |
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1. AFFORDABLE HOUSING |
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a. Benefit units consisting of rental housing permanently priced to serve nonsenior citizen low-income households (i.e., no greater than 30 percent of gross income for households at or below 50 percent of King County median income, adjusted for household size). A covenant on the site that specifies the income level being served, rent levels and requirements for reporting to the City of Sammamish shall be recorded at final approval. |
1.5 bonus units per benefit unit, up to a maximum of 30 low-income units per five acres of site area; projects on sites of less than five acres shall be limited to 30 low-income units. |
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b. Benefit units consisting of rental housing designed and permanently priced to serve low-income senior citizens (i.e., no greater than 30 percent of gross income for one or two-person households, one member of which is 62 years of age or older, with incomes at or below 50 percent of King County median income, adjusted for household size). A covenant on the site that specifies the income level being served, rent levels and requirements for reporting to the City of Sammamish shall be recorded at final approval. |
1.5 bonus units per benefit unit, up to a maximum of 60 low-income units per five acres of site area; projects on sites of less than five acres shall be limited to 60 low-income units. |
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c. Benefit units consisting of senior citizen assisted housing units 600 square feet or less. |
1.0 bonus unit per benefit unit. |
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d. Benefit units consisting of moderate income housing reserved for income- and asset-qualified home buyers (total household income at or below 80 percent of King County median, adjusted for household size). Benefit units shall be limited to owner-occupied housing with prices restricted based on typical underwriting ratios and other lending standards, and with no restriction placed on resale. Final approval conditions shall specify requirements for reporting to the City of Sammamish on both buyer eligibility and housing prices. |
0.75 bonus unit per benefit unit. |
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e. Benefit units consisting of moderate income housing reserved for income- and asset-qualified home buyers (total household income at or below 80 percent of King County median, adjusted for household size). Benefit units shall be limited to owner-occupied housing with prices restricted based on typical underwriting ratios and other lending standards, and with a 15-year restriction binding prices and eligibility on resale to qualified moderate income purchasers. Final approval conditions shall specify requirements for reporting to the City of Sammamish on both buyer eligibility and housing prices. |
1.0 bonus unit per benefit unit. |
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f. Benefit units consisting of moderate income housing reserved for income- and asset-qualified home buyers (total household income at or below 80 percent of King County median, adjusted for household size). Benefit units shall be limited to owner-occupied housing, with prices restricted to same income group, based on current underwriting ratios and other lending standards for 30 years from date of first sale. A covenant on the site that specifies the income level and other aspects of buyer eligibility, price levels and requirements for reporting to the City of Sammamish shall be recorded at final approval. |
1.5 bonus units per benefit unit. |
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g. Projects in which 100 percent of the units are reserved for moderate income- and asset-qualified buyers (total household income at or below 80 percent of the King County median, adjusted for household size). All units shall be limited to owner-occupied housing with prices restricted based on current underwriting ratios and other lending standards, and with prices restricted to same income group, for 15 years from date of first sale. Final approval conditions shall specify requirements for reporting to the City of Sammamish on both buyer eligibility and housing prices. |
200 percent of the base density of the underlying zone. Limited to parcels five acres or less in size and located in the R-4 through R-8 zones. Housing types in the R-4 or R-6 zones shall be limited to structures containing four or less units, except for townhouses. Such RDI proposals shall not be eligible to utilize other RDI bonus density incentives listed in this section. |
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h. Benefit units consisting of mobile home park space or pad reserved for the relocation of an insignia or non-insignia mobile home, that has been or will be displaced due to closure of a mobile home park located in incorporated or unincorporated King County. |
1.0 bonus unit per benefit unit. |
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2. OPEN SPACE, TRAILS AND PARKS |
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a. Dedication of park site or trail right-of-way meeting the City of Sammamish location and size standards for neighborhood, community or regional park, or trail, and accepted by the parks division. |
0.5 bonus unit per acre of park area or quarter-mile of trail exceeding the minimum requirement of Chapter 21A.30 SMC for on-site recreation space or trail corridors, computed on the number of dwelling units permitted by the site’s base density. |
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b. Improvement of dedicated park site to the City of Sammamish standards for developed parks. |
0.75 bonus unit per acre of park improvement. If the applicant is dedicating the site of the improvements, the bonus units earned by improvements shall be added to the bonus units earned by the dedication. |
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c. Improvement of dedicated trail segment to the City of Sammamish standards. |
1.8 bonus units per quarter-mile of trail constructed to City standard for pedestrian trails; or |
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2.5 bonus units per quarter-mile of trail constructed to City standard for multipurpose trails (pedestrian/ bicycle/equestrian). |
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Shorter segments shall be awarded bonus units on a pro rata basis. If the applicant is dedicating the site of the improvements, the bonus units earned by improvements shall be added to the bonus units earned by the dedication. |
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d. Dedication of open space, meeting the City of Sammamish acquisition standards to the City or a qualified public or private organization such as a nature conservancy. |
0.5 bonus unit per acre of open space. |
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3. ENERGY CONSERVATION |
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a. Benefit units that incorporate conservation features in the construction of all on-site dwelling units heated by electricity that save at least 20 percent of space heat energy use from the maximum permitted by the Northwest Energy Code, as amended. No more than 50 percent of the required savings may result from the installation of heat pumps. None of the required savings shall be achieved by reduction of glazing area below 15 percent of floor area. Energy use shall be expressed as allowable energy load per square foot or as total transmittance (UA). |
0.15 bonus unit per benefit unit that achieves the required savings. |
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b. Benefit units that incorporate conservation features in the construction of all on-site dwelling units heated by natural gas, or other non-electric heat source, that save at least 25 percent of space heat energy use from the maximum permitted by the Northwest Energy Code, as amended. None of the required savings shall be achieved by reduction of glazing area below 15 percent of floor area. Energy use shall be expressed as allowable energy load per square foot or as total transmittance (UA). |
0.10 bonus unit per benefit unit that achieves the required savings. |
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c. Developments located within one-quarter mile of transit routes served on at least a half-hourly basis during the peak hours and hourly during the daytime nonpeak hours. |
10 percent increase above the base density of the zone. |
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NOTE: When proposed energy conservation bonus units of SMC 21A.75.040 are reviewed in conjunction with a subdivision or a short subdivision, the applicant shall provide data and calculations for a typical house of the type to be built in the development that demonstrates to the department’s satisfaction how the required savings will be achieved. A condition of approval shall be recorded with the plat and shown on the title of each lot specifying the required energy savings that must be achieved in the construction of the dwelling unit. The plat notation shall also specify that the savings shall be based on the energy code in effect at the time of preliminary plat application. |
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(Ord. O99-29 § 1)
21A.75.050 Rules for calculating total permitted dwelling units.
(1) The formula for calculating the total number of dwelling units permitted through RDI review is as follows:
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DUs allowed by RDI site base density |
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Bonus DUs |
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DUs allowed by sending site density |
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Total RDI DUs |
(2) The total dwelling units permitted through RDI review shall be calculated using the following steps:
(a) Calculate the number of dwellings permitted by the base density of the site in accordance with Chapter 21A.25 SMC;
(b) Calculate the total number of bonus dwelling units earned by providing the public benefits listed in SMC 21A.75.040;
(c) Add the number of bonus dwelling units earned to the number of dwelling units permitted by the base density;
(d) Add the number of dwelling units permitted by the base density of the site sending TDCs, if any;
(e) Round fractional dwelling units to the nearest whole number; 0.49 or less dwelling units are rounded down; and
(f) On sites with more than one zone or zone density, the maximum density shall be calculated for the site area of each zone. Bonus units may be re-allocated within the zones in the same manner set forth for base units in SMC 21A.25.200. (Ord. O99-29 § 1)
21A.75.060 Review process.
(1) All RDI proposals shall be reviewed concurrently with a primary proposal to consider the proposed site plan and methods used to earn extra density as follows:
(a) For the purpose of this section, a primary proposal is defined as a proposed subdivision, conditional use permit or commercial building permit;
(b) When the primary proposal requires a public hearing under this code or SMC Title 19, the public hearing on the primary proposal shall serve as the hearing on the RDI proposal, and the reviewing authority shall make a consolidated decision on the proposed development and use of RDI;
(c) When the primary proposal does not require a public hearing under this code or SMC Title 19, the RDI proposal shall be subject to the decision criteria for conditional use permits outlined in Chapter 21A.100 SMC and to the procedures set forth for director/hearing examiner review in this title; and
(d) The notice for the RDI proposal also shall include the development’s proposed density and a general description of the public benefits offered to earn extra density.
(2) RDI applications that propose to earn bonus units by dedicating real property or public facilities shall include a letter from the applicable county receiving agency certifying that the proposed dedication qualifies for the density incentive and will be accepted by the agency or other qualifying organization. (Ord. O99-29 § 1)
21A.75.070 Minor adjustments in final site plans.
When issuing building permits in an approved RDI development, the department may allow minor adjustments in the approved site plan involving the location or dimensions of buildings or landscaping, provided such adjustments shall not:
(1) Increase the number of dwelling units;
(2) Decrease the amount of perimeter landscaping (if any);
(3) Decrease residential parking facilities (unless the number of dwelling units is decreased);
(4) Locate structures closer to any site boundary line; or
(5) Change the locations of any points of ingress and egress to the site. (Ord. O99-29 § 1)
21A.75.080 Applicability of development standards.
(1) RDI developments shall comply with dimensional standards of the zone with a base density most closely comparable to the total approved density of the RDI development; provided, that an RDI proposal in the R-4 through R-8 zone shall conform to the height requirements of the underlying zone in which it is located.
(2) RDI developments in the R-4 through R-8 zones shall be landscaped as follows:
(a) When 75 percent or more of the units in the RDI development consists of townhouses or apartments, the development shall provide perimeter landscaping and tree retention in accordance with Chapter 21A.35 SMC for townhouse or apartment projects.
(b) When less than 75 percent of the units in the RDI consists of townhouses or apartments, the development shall provide landscaping and tree retention in accordance with Chapter 21A.35 SMC for townhouses or apartments on the portion(s) of the development containing such units; provided, that if buildings containing such units are more than 100 feet from the development’s perimeter, the required landscaping may be reduced by 50 percent.
(c) All other portions of the RDI shall provide landscaping or retain trees in accordance with Chapter 21A.35 SMC.
(3) RDI developments in all other zones shall be landscaped or retain trees in accordance with Chapter 21A.35 SMC.
(4) RDI developments shall provide parking as follows:
(a) Projects with 100 percent affordable housing shall provide one off-street parking space per unit. The director may require additional parking, up to the maximum standards for attached dwelling units, which may be provided in common parking areas.
(b) All other RDI proposals shall provide parking for:
(i) Market rate/bonus units at levels consistent with Chapter 21A.40 SMC; and
(ii) Benefit units at 50 percent of the levels required for market rate/bonus units.
(5) RDI developments shall provide on-site recreation space as follows:
(a) Projects with 100 percent affordable housing shall provide recreation space at 50 percent of the levels required in Chapter 21A.30 SMC.
(b) All other RDI proposals shall provide recreation space for:
(i) Market rate/bonus units at levels consistent with Chapter 21A.30 SMC; and
(ii) Benefit units at 50 percent of the levels required for market rate/bonus units. (Ord. O99-29 § 1)