LEED v4 Site Credits: Heat Island, Rainwater, Open Space, Transit and Parking (v4, 2019 addenda)

For LEED v4 BD+C New Construction, the Sustainable Sites (SS) credits add up to 10 points and the Location and Transportation (LT) credits to 16. This article covers LEED v4 BD+C (July 2019 addenda); LEED v4.1 changed several of these credits, including rainwater management and the solar reflectance rules, and is not covered. LEED v5 has also been released (USGBC) and is not covered. All page references are to the LEED v4 BD+C rating system, July 2019 addenda, New Construction column.

SS and LT numbers at a glance

SS adds up to 1 + 2 + 1 + 3 + 2 + 1 = 10 points and LT to 1 + 2 + 5 + 5 + 1 + 1 + 1 = 16 points for New Construction. LT Credit LEED for Neighborhood Development Location (8-16 points for New Construction) is an alternative: a project that attempts it cannot earn points under other LT credits (p. 11). Core and Shell, Schools and Healthcare have different point values for several of these credits; check the rating system for those types.

What does the Construction Activity Pollution Prevention prerequisite require?

Create and implement an erosion and sedimentation control plan for all construction activities associated with the project. The plan must conform to the erosion and sedimentation requirements of the 2012 U.S. EPA Construction General Permit (CGP) or the local equivalent, whichever is more stringent, and must describe the measures implemented. The prerequisite states that projects must apply the CGP regardless of size (p. 30), so it is not limited to sites over 1 acre.

How does Heat Island Reduction work in LEED v4?

The credit is 1 to 2 points for New Construction and offers two options (pp. 38-39).

Option 1, Nonroof and Roof (2 points; 1 for Healthcare). The credit text gives an area formula (p. 38): the area of nonroof measures divided by 0.5, plus the area of high-reflectance roof divided by 0.75, plus the area of vegetated roof divided by 0.75, must be at least the total site paving area plus the total roof area. Dividing by the factor means a square foot of nonroof measure counts double and a square foot of roof counts 1.33 times. An SRI and solar reflectance weighted average approach may be used instead. Any combination of these strategies counts:

• Nonroof measures: existing or new plants that shade paving within 10 years of planting; vegetated planters; shade from structures covered by energy generation systems; shade from architectural devices or structures, or paving, with a three-year aged solar reflectance (SR) of at least 0.28 (if no aged value exists, an initial SR of at least 0.33); vegetated structures; and open-grid pavement that is at least 50% unbound.
• High-reflectance roof: SRI at or above the values in the table below, using the three-year aged value, or the initial value if no aged value exists.
• Vegetated roof.

Option 2, Parking under Cover (1 point). Place at least 75% of parking spaces under cover. Any roof that shades or covers parking must have a three-year aged SRI of at least 32 (initial SRI of at least 39 if no aged value exists), be a vegetated roof, or be covered by energy generation systems.

Non-roof paving is judged on solar reflectance (SR), not SRI: 0.28 aged or 0.33 initial.

What does Rainwater Management require?

The credit is worth 2 to 3 points for New Construction (1 to 2 for Healthcare) and has two options (p. 36).

Determine the percentile amount from daily rainfall data using the method in the EPA Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438 of the Energy Independence and Security Act. This is a separate calculation from the design storm used for local detention or flood control sizing, so ask the civil engineer for it as a distinct deliverable.

What does Open Space require?

One point. Provide outdoor space of at least 30% of the total site area, including the building footprint. At least 25% of that outdoor space must be vegetated (turf grass does not count) or have overhead vegetated canopy. The space must be physically accessible and be one or more of: a pedestrian-oriented paving or turf area with elements for social activity; a recreation-oriented area encouraging physical activity; a garden with diverse vegetation giving year-round visual interest; a community garden or urban food production space; or preserved or created habitat that meets the SS Protect or Restore Habitat criteria and includes elements of human interaction. Accessible vegetated roofs count toward the 25% vegetation requirement on projects with a density of 1.5 FAR (p. 35).

How does Access to Quality Transit work?

For New Construction the credit is 1 to 5 points (p. 18). A functional entry must be within a 1/4-mile (400 m) walking distance of existing or planned bus, streetcar or rideshare stops, or within a 1/2-mile (800 m) walking distance of existing or planned bus rapid transit stops, light or heavy rail stations, commuter rail stations or commuter ferry terminals. Service at those stops counts in aggregate and must meet both the weekday and weekend trip minimums. Qualifying routes need paired service in opposite directions, only trips in one direction count, and where a route has several stops within range only one stop’s trips count.

Projects with commuter rail or ferry service only use a separate table (24 weekday and 6 weekend trips for 1 point; 40 and 8 for 2; 60 and 12 for 3). A project served by two or more routes, none providing more than 60% of the documented levels, may earn one additional point up to the maximum. Planned stops count if sited, funded and under construction by the certificate of occupancy date and complete within 24 months of it. Count trips, not headways: a stop at the right distance with too few weekday or weekend trips does not qualify.

What do Bicycle Facilities and Green Vehicles require?

Bicycle Facilities (1 point, p. 21). Commercial and institutional projects need a functional entry or bicycle storage within 200 yards (180 m) walking or bicycling distance of a bicycle network that connects to at least 10 diverse uses, a school or employment center (for projects 50% or more residential), or a bus rapid transit stop, rail station or ferry terminal, with all destinations within a 3-mile (4800 m) bicycling distance. Provide short-term storage for at least 2.5% of peak visitors (no fewer than four spaces per building) and long-term storage for at least 5% of regular building occupants (no fewer than four spaces in addition). Provide at least one on-site shower with changing facility for the first 100 regular building occupants and one more for every 150 thereafter. Residential projects have a separate case in the credit.

Green Vehicles (1 point, p. 27). Designate 5% of all parking spaces used by the project as preferred parking for green vehicles (minimum ACEEE green score of 45), or offer a discounted parking rate of at least 20%. In addition, either install electric vehicle supply equipment (EVSE) in 2% of all parking spaces, in addition to the preferred spaces, at Level 2 (208-240 V) or greater and networked, or provide liquid, gas or battery-switching facilities.

Which mistakes cost points on these credits?

• Using the local design storm for rainwater. The credit asks for the 95th or 98th percentile of daily rainfall events by the EPA Section 438 method; a flood-control detention calculation is a different number.
• Judging non-roof paving by SRI. Nonroof paving and shade structures are measured by solar reflectance (0.28 aged, 0.33 initial); SRI values are for roofs.
• Counting transit by distance alone. The credit needs weekday and weekend trip counts from the transit agency schedules, with paired routes.
• Installing bicycle racks and no showers. Commercial projects need the shower and changing facilities as well as long-term storage.
• Treating the EV requirement as 5% of spaces. The 5% is preferred parking for green vehicles; EVSE is a separate 2% of spaces.
• Assuming the construction prerequisite depends on site size. It applies to every project.