Page 52 - Zero Net Energy Case Study Buildings-Volume 3

CASE STUDY NO. 13
LA ESCUELITA EDUCATION CENTER
Since 2007 Oakland Unified School District (OUSD) had a policy committed to the design and construction of sustainable facilities based on the principles of the Collaborative for High Perfor- mance Schools1 (CHPS). The District hired a sustainability consultant to assist in the develop- ment of their “green schools” program, which prioritized “low energy design” with a gradually increasing energy performance goal aimed at zero-net-energy. The LEEC project was one of the largest projects in OUSD’s ongoing bond program and the District was able to secure matching state funds for this project’s energy-related high performance goals.
Design Process and Low Energy Design Strategies
OUSD first selected the architectural firm through the usual evaluation procedure, who as part of this process developed a concept design for the entire program to be placed on the site. This master plan reflected primarily programmatic accommodation, including required outdoor space and parking. (See figure on the facing page.)
At the same time, OUSD leaders and the sustainability consultant advanced a “stretch goal” for the project, namely to design the first zero-net-energy K-12 campus. To that end, OUSD and the architect filled out the design team for the next design phases by selecting engineering consul- tants who had a record of successful work with the design of zero-net-energy (ZNE) buildings.
With the new, ZNE-experienced consultant team in place, the design team set about integrat- ing energy-efficient design strategies into the planning of the site and buildings per the program requirements and phasing concept. In addition, the project team was required to meet all of the requirements of CHPS, which included factors such as thermal comfort, indoor air quality and commissioning.
In general, the OUSD project leaders supported the idea of “experimental design strategies” to be explored rather than conventional systems that maintenance staff might accept as a more comfortable approach, as a means of gaining experience with systems that might be applied to future projects. The design team was charged with proving that any new approach to the design would provide deep energy savings and would work within the established project budget.
Planning Concept and General Design Considerations
Reviewing the originally proposed concept design of the building program components on the site (facing page, top), and taking note of the site orientation relative to the sun, the design team reorganized the site plan so that the buildings would face primarily south to provide better daylighting, more effective solar control and solar PV system optimization. The phasing require- ments were considered as well, allowing the Metwest High School campus to continue operation while Phase 1 was built. The resulting building plans and campus organization (shown on the facing page, bottom, and the two following pages) were as a result dramatically different than the original concept where energy use and on-site PV production were not considered in an integrated way.
An initial analysis of the expected energy use for the campus was done using CBECS data2 as a benchmark for comparable space types and assuming realistic energy-efficiency improvements to lower these benchmark numbers. Even assuming the most optimistic reduction by design in the energy demand of the programmed spaces, the required on-site installation of the solar PV to offset this expected demand was several times the space available on building roofs and pos- sible parking lot canopy structures.
1 See http://www.chps.net/
2 Commercial Buildings Energy Consumption Survey, https://www.eia.gov/consumption/com- mercial/
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Zero Net Energy Case Study Buildings: Volume 3