LEED BD+C: Core and Shell v2 - LEED 2.0
LEED Gold 2010
The below stakeholder perspectives address the following LEED credits:
SSc5.2, WEc1.1, MRc2.2, SSc9, SSc3, EAc8.1, SSc6.2, EAc6
* This profile has been peer-reviewed by a USGBC-selected team of technical experts.
Goals and motivations
What were the top overarching goals and objectives?
The main goals and objectives of the project were to rehabilitate a 25-acre lot to provide a much-needed retail hub in one of the most impoverished communities in the area. The development of the shopping center is intended to provide locals much-needed resources and jobs, and to draw visitors into the community.
What were the motivations to pursue LEED certification and how did they influence the project?
- Organizational Priority
- Policy/Code Requirement
- Waste Reduction/Avoidance
With all Primestor projects, making sure all projects create positive community impacts is critical. In the case of Plaza Pacoima, transforming the site from a brownfield into an energy-efficient center of the community was a goal for Primestor, the tenants, and the community. All issues, from construction debris to site lighting, were considered to achieve this goal to the highest degree possible. Although the development team had a goal to achieve LEED Silver certification, the team's mutual interest to meet this goal allowed the project to excel and obtain LEED Gold.
What were the most notable strategies used to earn LEED credits?
We designed the project to maximize open space, earning a LEED Innovation in Design (ID) point for exemplary performance. Strategies used for open space served additional functions, including reducing the heat island effect and stormwater run-off. The open space was not a contiguous parcel; rather, we provided pockets of open space throughout the parking lot and along the sidewalks. We located drought-tolerant landscaping within parking lot planters and all along the pedestrian sidewalks connecting the buildings. Nearly 300 trees were planted to provide shading, encouraging pedestrians to walk between buildings in lieu of driving. In comparison to traditional retail parking lots, Plaza Pacoima features landscaping behind wheel stops and between parking stalls; this landscaping provides shade and supports a stormwater management plan by reducing surface water run-off during rain events and increasing water infiltration into the soil. Given the location on a brownfield, we had to ensure that planters were not located in certain areas with elevated levels of gases (which are monitored) in the soil, so that water does not infiltrate here.
This photo illustrates the newly-installed landscaping planters in the parking lot, used to capture rainwater to slow and filter it. Photo by Wajid Drabu.
Another big success was diverting 99% of construction waste, for which the project earned a LEED ID point for exemplary performance. This all started with a waste management plan developed by the general contractor (GC). Once the plan was completed, all of the sub-contractors were educated and informed of the waste management plan and the original 75% waste diversion goal. The construction team set up crushers to demolish existing structures and roadways on-site and reused the crushed materials for site work, thereby eliminating the need to haul away the debris. The GC selected a waste hauler that shipped all of the comingled waste materials to a sorting facility, reducing the need to sort everything perfectly on-site. The sorting facility separated different material types using conveyor belts, manual laborers, magnets, and shredders. Careful attention was paid to the hauling tickets and the sorting facility paperwork to ensure that all of the recycled materials were documented. In the end, we achieved a higher percentage of diverted materials than our goal.
Being located in sunny California, we harvested natural light into the buildings by using high storefront glazing, skylights, and solatubes that actually bend and direct sunlight into the ceiling diffuser and give the appearance of a standard lay-in type light fixture without using any energy. These strategies resulted in 100% daylight in all regularly-occupied spaces, earning an exemplary performance ID point. The Best Buy building incorporated more than 40 skylights to bring natural light into the sales floor and reduce electrical demand for lighting during the day. The skylights and light fixtures were tied into light sensors and dimming controls so that the building could automatically adjust the lighting levels based on current conditions and daylight entering the store through the skylights. Green power was purchased, helping the project earn enough credits to achieve LEED Gold. All sub-tenant spaces are separately metered using small EMON-DMON type electrical sub-meters that were installed above the ceiling, enabling each tenant to monitor its own energy use. The project is estimated to have 17.5% in energy cost savings.
Last, water use reduction was a priority. The project earned an exemplary performance ID point by attaining 45% water savings through the use of water-efficient flush and flow fixtures inside the buildings.
What cutting-edge strategies or processes were implemented?
With the site being impacted by many years of pollution and surrounded by a chain link fence, it was a focus to turn the area into a place people would want to visit. The project was located on a very large site and with multiple big box retail buildings comes the need for a large parking lot. To reduce the impact on the existing municipal stormwater system, all water that falls on the site stays on-site, infiltrating into the soil. Water is directed into slotted curbs in parking lot planters, allowing it to be collected, the flow slowed down, and then filtered through a filtering medium. The filtering medium consists of an organic soil and stone aggregate to naturally filter pollutants and, in turn, reduce stormwater runoff, help reduce the quantity of water, and clean the water prior to entering into the municipal system.
Before deciding upon this stormwater management strategy, the team considered another option: To dig very deep holes in the ground for piping, catch basins, and very large detention basins filled with sand for filtering runoff. But not only would this have been a very expensive alternative, it would have also required more maintenance than the strategy implemented.
Aside from LEED certification, what do you consider key project successes?
The key success to the project was transforming a large quarantined brownfield site into a place of community where people would want to eat, shop, and work. This development has helped to revitalize a struggling community by creating 438 construction jobs and 354 permanent living wage jobs in compliance with the Community Redevelopment Agency of Los Angeles' first source and local hire programs.
What were the most important long- and short-term value-add strategies and what returns on investment (ROI) have been experienced or anticipated?
Due to the project being LEED for Core & Shell, the developer provided design requirements for the retail tenants to improve efficiency of mechanical systems and plumbing fixtures in their build-outs. The tenant lease agreements mandate low-flow/flush rates for fixtures and air handler efficiency ratings that should result in long-term water and energy savings.
The extensive skylights and solatubes located on the roofs of all of the buildings provide much of the required lighting inside of the buildings. Daylight strategies combined with light controls help reduce electricity costs in a very sunny climate area. The lighting power density (footcandles) inside the buildings were reduced slightly below code, which is not typical in a retail type setting where displays and merchandise are usually very illuminated. Although remediating the brownfield site was quite extensive and costly, federal and local tax incentives helped to offset these costs.
The Best Buy building features more than 40 skylights that bring natural light into the sales floor, reducing electrical demand during the day. The light fixtures have sensors that automatically adjust lighting levels based on need. Photo by Rick Martin.
What project challenges became important lessons learned?
One challenge that the project team encountered was the detailing of the flow-through planters in the parking lot. In this climate, it does not rain very frequently; however, when it does, it is very fast and floods the storm drain system all at once. During the installation of the planters' protective plastic lining, there was a rain event that flooded the planters and filled them with water, causing the plastic lining to separate from the concrete curbs and washing soil into the parking lot. This issue was resolved by cutting a small slot at the top of the concrete curb and securing the plastic lining into the slot. The planters were also re-graded and jute netting was installed to keep soil and mulch in place during heavy rain events. In hindsight, this challenge probably could have been reduced had we used an integrated team approach, giving the team more options during design and facilitating coordination.
What was a pivotal moment that impacted the project's direction?
The original project goal was to obtain LEED Silver certification. After the design review was approved and during the final months of documenting the construction submittal, it was apparent that the project was only a few credits short of LEED Gold. At this late stage, Primestor requested all of the consultants to review and advise of any potential LEED credits that could be added, but we were limited. Ultimately, the team advised Primestor to purchase a green power agreement (REC) to obtain the necessary credits to achieve LEED Gold.
Since this experience, we have now created a new column on the LEED scorecard. The LEED scorecards currently have a "Yes" column, a "?" column, and a "No" column. We kept the Yes column for credits we feel very confident in achieving, but created two new columns called, "Maybe Yes" and "Maybe No," and eliminated the "?" column; the "No" column is left for credits that are definitely not achievable. This helps us organize the credits at a higher level and also identify any potential credits earlier.
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