Page 45 - Zero Net Energy Case Study Buildings-Volume 1

STEVENS LIBRARY AT SACRED HEART SCHOOLS
Low Energy Design Strategies for Stevens Library
While the low construction cost budget pointed at a simple shape and standard details for the building, this also led to ample flat roof area for a solar photovoltaic system. The cost issue also drove a number of other design decisions as described in the paragraphs below, but low energy performance was not compromised in seeking solutions to minimize cost. Simple, straightfor- ward solutions for energy-related features and systems became the design approach.
Planning/Concept and Building Envelope
The library program required a largely open main space for stacks, seating and computers with optimal low-glare conditions. The building envelope, therefore, is essentially a simple box with carefully placed tall windows that are deeply set back on the southerly side and some top-lighting at the roof for visually comfortable daylighting. The tall windows with high performance glazing contain operable components and are located opposite each other to allow for cross ventilation under appropriate outdoor conditions.
The framing originally was all wood stud construction, but was switched for cost reasons to metal stud framing centered at 24”. To compensate for the introduction of the thermal bridging effect that accompanies metal stud construction, 1-inch thick rigid insulation was added to the walls and 2-inch rigid insulation at the roof to form a continuous insulating layer around the building. The final result is a building envelope insulated to an economic but sufficient level, with R-15 walls and a R-38 white-colored roof.
While this envelope would not be characterized as heavily insulated, it is sufficient to keep the overall energy demand low enough so that the total annual energy demand can be met by the high-efficiency roof-top solar photovoltaic panels. Generally, however, it is more economic to save energy through efficiency measures than to produce energy through solar PV panels. In this case, because any over-production may be used in the future for the other buildings on the quad, the maximum number of solar photovoltaic panels were installed on the roof.
(Below) View of Southwest Elevation
CASE STUDY NO. 2
PHOTO: BRUCE DAMONTE
Zero Net Energy Case Study Buildings: Volume 1
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