12.50.930 Sustainable Development Practices.

A.  Habitat Friendly Development Practices. Use of habitat friendly development practices, including Low Impact-Development Approach (LIDA) techniques are a key element of the adopted Tualatin Basin Fish & Wildlife Habitat Program. LID techniques are encouraged to reduce the environmental impacts of new development, and to provide flexibility to encourage the protection of qualified Habitat Benefit Areas. The following recommended habitat-friendly development practices should be considered where technically feasible and appropriate.

1.   Design and Construction Practices to Reduce Hydrologic Impacts.

a.   Amending disturbed soils to original or higher levels of porosity to regain infiltration and stormwater storage capacity.

b.   Using pervious paving materials for residential driveways, parking lots, walkways, and within centers of cul-de-sacs.

c.   Incorporating stormwater management in street rights-of-ways, subject to the approval of the City Engineer.

d.   Landscaping with rain gardens to provide on-lot detention and filtering and groundwater recharge.

e.   Using green roofs to reduce runoff and energy costs, improve air quality, and enhance aesthetics.

f.    Disconnecting downspouts from roofs and direct rainwater to vegetated infiltration / filtration areas.

g.   Retaining rooftop runoff in rain barrels for future on-site irrigation.

h.   Using multi-functional open drainage systems in lieu of conventional curb-and-gutter systems.

i.    Using bioretention cells in parking lot islands to reduce runoff volume and filter pollutants.

j.    Applying a site-specific combination of storm water systems (a “treatment train”) to provide multiple opportunities for treatment and to reduce the possibility of system failure.

k.   Reducing sidewalk widths and slope grades to drain into front yards or retention areas.

l.    Reducing impervious surface areas of residential driveways by narrowing widths or using shared driveways.

m.  Reducing widths of residential streets, depending on traffic and parking needs.

n.   Reducing street length, primarily in residential areas, by encouraging clustering and using curvilinear designs.

o.   Reducing cul-de-sac radii and use pervious vegetated islands in center to minimize impervious effects, and allow them to be utilized for truck maneuvering/loading to reduce need for wide loading areas on site.

p.   Eliminating redundant non-ADA sidewalks within a site (i.e., sidewalk to all entryways and/or to truck loading areas may be unnecessary for industrial developments).

q.   Minimizing car spaces and stall dimensions, reducing parking ratios, and using shared parking facilities and structured parking.

r.    Minimizing the number of stream crossings and place crossings perpendicular to the stream channel if possible.

s.    Allowing narrower street right-of-ways through stream corridors whenever possible to reduce adverse impacts of transportation corridors.

2.   Design and Construction Practices to Minimize Impacts on Wildlife Corridors and Fish Passage.

a.   Integrating fencing into site vegetation to guide animals toward crossings under, over, or around streets and roads.

b.   Using bridge crossings rather than culverts wherever possible.

c.   If culverts are utilized, installing slab, arch or box culverts, preferably using bottomless designs that more closely mimic stream bottom habitat.

d.   Designing stream crossings for fish passage and other design features to facilitate terrestrial wildlife passage, as illustrated in Figure 12.50.930-A.

Figure 12.50.930-A:

Examples of Stream Crossings with Fish and Terrestrial Wildlife Passage Provided

e.   Extending vegetative cover through the wildlife crossing in the migratory route, along with sheltering areas.

3.   Miscellaneous other Habitat-Friendly Design and Construction Practices.

a.   Using native plants throughout the development, not only in Habitat Benefit Areas.

b.   Locating required landscaping adjacent to Habitat Benefit Areas.

c.   Reducing light-spill off into Habitat Benefit Areas from development.

d.   Preserving and maintaining existing trees and tree canopy coverage, and plant trees where appropriate to increase future tree canopy coverage.

B.  Water Usage Efficiency and Reduction.

1.   Collecting and storing rainwater and/or graywater with sediment filtration and using for irrigation, especially during summer. Where installed, above-ground cisterns for rainwater or graywater collection must meet the following standards:

a.   Individual cisterns or racks of cisterns larger than 80 gallon capacity may not be attached to the front façade of the primary structure; and

b.   Cisterns must either be painted to match the color of the adjacent building wall, the trim, or the rain gutter; or be screened from the street by structures, plantings, or fences.

2.   Using efficient irrigation including high efficiency drip irrigation.

3.   Using native and drought-tolerant vegetation for landscaping; limit lawn to play and recreational areas.

4.   Using water-conserving plumbing fixtures.

5.   Installing water conserving or energy efficient appliances.

C.  Energy Usage Efficiency and Reduction.

1.   Designing and site buildings to maximize natural ventilation and solar access for heating and lighting.

2.   Installing operable windows with energy-efficient glazing.

3.   Using energy-efficient outdoor lighting with low temperature ballasts; fixtures with automatic controls; and solar lighting for walkways or outdoor areas.

4.   Centrally locating heating/cooling systems to reduce the extent of the distribution system.

5.   Increasing insulation to at least 10% above IBC requirements.

6.   Flashing and sealing all penetration points for ducting, wiring, plumbing, lights and fans.

7.   Using cool roofs wherever practicable.

8.   Using alternative heating systems, such as ground-source heat pumps; radiant heating; on-demand water heaters; solar heating or others.

9.   Using alternative electric generation systems, such as solar photovoltaic or wind energy.

a.   Where installed, solar electric systems must meet the following standards:

i.    On a flat roof, the panels must be mounted flush or on racks. Panels or racks cannot extend more than 5 feet above the top of the highest point of the roof, not including the parapet wall, and must be set back at least 5 feet from the edge of the roof.

ii.   On a pitched roof, the plane of the panels must be set back at least 3 feet from both the eave and the ridgeline.

iii.  Photovoltaic roofing shingles or tiles may be directly applied to the roof surface.

iv.  Photovoltaic glazing may be integrated into windows or skylights.

b.   Where installed, roof-mounted wind turbine systems must meet the following standards:

i.    Wind turbines may be proposed only on buildings meeting the minimum setbacks of the applicable zone.

ii.   The height of a roof-mounted wind turbine may exceed the base zone height by up to 50%, or 25 feet above the height of the building on which it is mounted, whichever is less.

iii.  Turbines must have an AWEA-rated sound level of 45dBA or less. The noise standards of the Hillsboro Municipal Code also apply to wind turbine operation.

D.  Storm Water Management. The following methods should be used to reduce contaminants from hard surfaces, improve infiltration improvement, and reduce or eliminate water quality treatment or detention facilities.

1.   Minimizing impervious surfaces at and above grade.

2.   Using eco roofs and roof gardens wherever practicable.

3.   Using pervious paving for parking areas and walkways.

4.   Using infiltration or flow-through planters, bio-retention cells, and/or rain gardens.

E.   Green Building Materials. The following methods should be used to improve indoor air quality.

1.   Using recycled-content building materials where practicable.

2.   Using locally made or harvested materials and products.

3.   Using certified or recycled wood.

4.   Using low- or no-VOC (Volatile Organic Compounds), low-toxic interior paint and water-based finishes and stains.

5.   Using formaldehyde-free carpet, cabinets and insulation.

6.   Using low-VOC, low-toxic, water-based, solvent-free adhesives, caulks, grouts, mortars, and sealants on building interiors.

7.   Using longer life-cycle and/or recyclable exterior materials (roofing and siding).

8.   Limiting use of carpet; use low pile or less allergen-attracting brands; and install by tacking (without glue).

F.   Noise and Privacy. The following methods should be used to reduce external and internal noise and enhance privacy.

1.   Using enhanced landscaping or water features to buffer or mask sound.

2.   Providing internal streets and sidewalks to buffer activity and noise.

3.   Locating bedrooms and quiet rooms away from noise sources.

4.   Insulating activity rooms.

5.   Providing sound-rated walls, floors and sound-absorbing materials on the building exterior.

6.   Locating shared community and/or commercial spaces on the first floor.

7.   Defining edges through building locations, elevations or changes in materials, vegetation, fencing, elevated entries or other features.

G.  Accessibility and Visitability.

1.   Providing “zero-rise” residential entries without steps or thresholds.

2.   Providing paths of travel from the street, sidewalk or driveway which have no steps, are at least 36-inches wide and are no steeper than 1:20 (5% grade) for walkways or 1:12 for ramps.

3.   Providing ground floor residential entries with 32-inch clear opening doorways and 36-inch clear width hallways.

4.   In dwellings, providing at least a half bath on the ground floor, with adequate dimensions to allow a person in a wheelchair to enter and close the door.

H.  Third Places.

1.   Designing residential developments to include multi-purpose indoor or outdoor spaces. Interior multi-purpose rooms should accommodate both passive and active assembly Uses (such as community meetings and exercise classes). Outdoor multi-purpose spaces should accommodate both passive Uses (such as wetland viewing areas) and active Uses (such as sport courts or community gardens).

2.   Designing Mixed-Use and non-residential developments to include outdoor hardscaped plazas or courtyards which could accommodate both private Uses (such as sidewalk seating for restaurants) and public Uses (such as farmers markets and street vendors). (Ord. 6401 § 1, 2022)