sorting and recovery process. An example of this shift occurred at the Presidio Branch. Crews trained in the materials recovery process disassembled sections of walls designated for demolition and sorted the wall systems into plaster/ gypsum, wood, and metal which were all taken to recology for recycling. The Indoor Air Quality Plan, or IAQ plan, for LEED involves adopting specific guidelines and practices published by the Sheet Metal & Air Conditioning Contractors’ National Association (SMACNA). In the IAQ plan the SMACNA guidelines and practices were called IAQ protective measures and were incorporated into job site housekeeping and safety practices, as well as materials specifications. Communication of IAQ inspection tasks linked the specific IAQ protective measures to not only achieving the intent of the LEED credits and the goals of the project, but also to the benefits of worker and occupant safety. Workers were encouraged to engage in open dialogue about their concerns of the “trade-offs” of transitioning away from conventional practices and materials and adopting the sustainable methods. Through the expression of opinions and preference differences, crew members developed their own motivations for adopting sustainable methods based upon their individual set of values, existing working relations, and company resources. The dialogue facilitated cross-team clarification of job site performance expectations while crew members decided individually and as teams how to best to adapt their practices to meet the project goals. By emphasizing the learning processes that would help subcontractors become more competitive for future green building jobs and meeting new CalGREEN standards, language was used to develop intrinsic motivation and crew member accountability in adopting sustainable building practices.
LEED CONSTRUCTION PROCESSES Materials & Resource credits (MR credits) The construction project team achieved four out of six points attempted in the Materials and Resources category for use of salvaged materials (for two points) and construction waste management (also for two points with an additional point awarded under Innovation for exemplary performance). By implementing a comprehensive Construction Materials Recovery Plan that minimized the amount of materials sent to landfills from the construction and demolition (C&D) processes, both projects earned three points for achieving the landfill diversion rates shown in Table 1.
Facility
Overall Project Diversion Rate
C&D Diversion
Recycle & Compost
Additional GHG reduction over 65% diversion ordinance
Additional % GHG reduction for CMR
Park
97.97
74.65 tons
1.56 tons
18 metric ton CO2 equivalent
51%
Persidio
98.89
168.34 tons
2.12 tons
31 metric ton Co2 equivalent
70%
Table 1: SFPL Park and Presidio Branch Contruction Materials Recovery Data * GHG emissions calculated using EPA’s WARM online calculator based on the project performance in material diversion and use of thwe three-bin system against the City of San Francisco Construction and Demolition ordinance requirement of minimum 65% diversion and no construction site use of the three bin system as the baseline case.
146 | Urban action 2012