In keeping with the city's comprehensive plan goal of allowing for density bonuses for excellence in design, the applicant may obtain additional density for environmental, low impact development, affordable and view protection design by incorporating the following alternatives; provided, that by incorporating all three alternatives into a lot and building design the minimum lot area and dimension will be eligible for a 10 percent lot area and dimension reduction for that lot. For example: by constructing a single-family ranch style home in the R-6,000 zone, 18 feet in height, that certifies as "built green" on a lot that has met the SLID option, the minimum lot size may be reduced by 10 percent from 4,500 square feet to 4,050 square feet, the 45-foot minimum lot width reduced to 40 feet, and the lot area coverage increased from 35 percent to 45 percent.
(1)
Green Building. Where a developer can demonstrate that a building certifies as "built green" under the Washington State Master Builders Association, and that green building techniques will be used to significantly reduce the ecological footprint of any individual lot, that lot size may be reduced by an additional four percent.
(a)
Findings Required. Green building will be considered eligible for the four percent lot size reduction if the developer can demonstrate that their plans and techniques qualify as a "built green" building under the Washington State Master Builders Association Certification. This determination of eligibility is subject to the findings of the planning director.
(b)
Bond. The developer shall be required to post a bond of 150 percent of the assessed value of the lot in question to assure compliance with proposed green building plans.
(2)
Stormwater Runoff.
(a)
Stormwater runoff shall be per compliance with Chapter 14.30 BMC.
(b)
Sustainable Low Impact Development (SLID) Option. Residential clusters may apply at least two of the following stormwater runoff mitigation techniques in addition to maintaining existing vegetation as possible:
(i)
Raingardens. Provision of a raingarden on each lot where possible or on site at a common location.
(ii)
Permeable/porous parking lanes, alleys, driveways, sidewalks, paved patios, and decks.
(iii)
Grass-lined and landscaped swales.
(iv)
Natural drainage corridors and ponds.
(c)
If using the SLID option, the minimum size of that lot size may be reduced by an additional four percent.
(d)
Any SLID measures implemented shall be required to be included within a stormwater maintenance agreement for the development to ensure continuous long-term maintenance.
(3)
Single-family ramblers/ranch style designs not exceeding 20 feet in height are permitted at higher lot area coverage on the smallest of allowed lot sizes; provided the setback yard requirements of BMC § 19.23.055 are met. This design exception is allowed an increase of up to 10 percent of allowable lot area coverage (based on the underlying zone).
(Ord. 22-08 § 1 (Exh. A), 2008)