Page 88 - Zero Net Energy Case Study Buildings-Volume 2

CASE STUDY NO. 10 WEST BERKELEY BRANCH LIBRARY
West Berkeley Branch Library
Case Study No. 10
Data Summary
Building Type: Civic / Library Location: Berkeley, CA Gross Floor Area: 9,300 gsf Occupied: January 2014
Energy Modeling Software:
DesignBuilder v2.1 (updated modeling using v4.5.0.178)
Modeled EUI (Site):
17.5 kBtu/sq.ft.-year
Measured EUI (Site):
23.1 kBtu/sq.ft.-year (2014)
On-Site Renewable Energy System Installed:
52.2 kW (DC) Solar PV
Measured On-Site Energy Production:
75,350 kWh per year
27.7 kBtu/sq.ft.-year (2014)
Owner/Client
City of Berkeley, Berkeley Pub- lic Library
Design Team
Architect: Harley Ellis De- vereaux, Berkeley Office and Los Angeles, CA
Structural Engineer:
Tipping-Mar, Berkeley, CA
The West Berkeley Branch Library is a model for the basic design process of a ZNE building, particularly for a building in the public sector. The project demonstrates the sequence of typical steps starting in concept design and the timely integration of energy-related design principles with the basic aspects of program, spatial relationships, structure and building form. The design process discussed in this case study also illustrates typical timing of technical studies, including computer modeling, and recommended steps through construction and post-occupancy.
The case study project is also an example of the typical public project financial model as applied to ZNE buildings, as opposed to private owners with their own programs and financial objectives, namely a fixed budget with no additional funds earmarked for ZNE design features or systems. The ZNE design must be achieved using a pre-established fixed budget that is usually based on a code-minimum building.
Public clients typically have a lengthy funding process with fixed construction budgets that are determined well in advance of design and construction. While some design alternatives can be evaluated based on life cycle cost, the bottom line for the total project remains a fixed amount that cannot be exceeded. Conversely, if the project is over budget in mid-design, value engineer- ing to reduce cost may consider life cycle cost advantages for some building features or systems, but the sum of all selected cost reductions must result in the project meeting the fixed budget.
Background
After years of studies, grant applications and master planning (2000-2008) to replace the inade- quate existing branch library at the project site, the voters of the City of Berkeley passed a library bond measure to fund the construction of this branch library, as well as three other branches within the city. The construction budget was set at $5.5 million for the West Branch in 2008; the budget remained at this amount up to the time of bidding four years later in 2012, without any adjustment for inflation during the protracted design approvals period. The project was planned to follow the typical public process of design-bid-build, resulting in a code-minimum building and any adjustments needed to obtain a LEED-Silver rating.
The design team, however, proposed a more aggressive approach to the client, the Berkeley Public Library, suggesting that the building was an ideal candidate for a ZNE design and that this higher goal could be achieved within the fixed budget allotted to the project. The client agreed to allow the design team to proceed with this approach provided the library program was met in full and the final ZNE design satisfied all budget requirements.
The project approvals process started early in the design phases and included a substantial number of public meetings and commentary, including design review and even a lawsuit. A prin- cipal issue was the demolition of the remaining portion of the original 1923 building on the project site, which had received a city designation as a “structure of merit”. One of the arguments used against the new ZNE design and in favor of the restoration of this original building was embod- ied energy. The design team was able to show that the extra embodied energy needed for the construction of the ZNE design, including that of the glass solar PV panels, would be equaled by the energy saved in operation after only 1.5 years. The calculation demonstrated that the ZNE building design was by far the low-energy and low-carbon alternative.
The general interest in the community for constructing a ZNE public building, combined with library operation factors, led to a near-unanimous approval by the Berkeley City Council for the ZNE design as proposed.
Mechanical/Electrical/Plumbing Design Engineer:
Timmons Design Engineers, San Francisco, CA
Energy Modeling:
GreenWorks Studio, Los Angeles,CA
Lighting Design: Max Pierson, San Francisco, CA
Landscape Architect:
John Northmore Roberts & As- sociates, Berkeley, CA
General Contractor
West Bay Builders, Novato, CA
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Zero Net Energy Case Study Buildings: Volume 2