EWEB: Meeting our Client's Unique Sustainability Goals
Lewis was hired by EWEB, an Oregon public utility, to build a new operations center that meets the requirements for LEED Gold certification, while demonstrating the agency’s commitment to energy efficiency, resource stewardship and fiduciary responsibility.
Our efforts began early in preconstruction, with thoughtful analysis of integrated design strategies, life cycle costs, building system selection and means and methods. Continuing into construction, we have devised means and methods that maximize the achievement of LEED credits, optimize building efficiency and minimize operational costs. Specific examples include the following:
RECYCLED AND REGIONAL MATERIALS
Lewis collaborated with subcontractors and suppliers to source materials with high recycled content, manufactured and extracted regionally, which limited resource use and reduced carbon emissions associated with materials transport. For example, our team sourced steel with a 98% recycled content, 85% of which was fabricated and extracted regionally, resulting in an additional LEED credit.
As part of the daylighting design, acrylic prismatic skylights provide light to second floor work spaces and first floor light wells. We are mocking up two different styles of acrylic skylights (pyramid and hipped-dome) to measure their performance in winter when the sun is lower and less light is available. This analysis will identify which style provides the best light distribution in our region, thus reducing the need for energy-consuming artificial lighting.
LOW EMITTING MATERIALS
The project team originally intended to achieve all low emitting materials LEED credits, except for EQ4.4: Composite Wood and Agrifibre Products, since the core material specified for the building’s marker boards was not urea formaldehyde free. Lewis suggested an alternate, LEED EQ4.4 compliant marker board, making it possible to pursue an additional credit.
Seven and one quarter inch thick concrete tilt up panels provide for slower and steadier heat gain and loss, using night air for cooling in the summer and solar heat in winter.
The preliminary thermal insulation design was laborious to construct, the blanket and batt insulation design had an R-value of just 15.15, and the insulation product proposed was not urea formaldehyde free. Lewis devised a solution that was fast to construct, achieved a higher R-value of 18.87 (reducing energy costs) and utilized insulation free of urea formaldehyde at no additional cost.
As a result of our efforts, EWEB is currently projecting 42 certain credits and 4 probable, exceeding the 39 credits required to achieve LEED Gold certification. Energy models are forecasting energy cost savings of 46% and water conservation measures are anticipated to reduce consumption by 82%. Additionally, Lewis is on track to deliver the project at a cost of $50 million, 16% less than the target budget.