Page 8 - Zero Net Energy Case Study Buildings-Volume 2

ZERO NET ENERGY CASE STUDY BUILDINGS, VOL. 2 INTRODUCTION
Introduction
The February 2016 issue of Architect magazine, a journal published by the American Institute of Architects, closed with a noteworthy editorial on its last page, entitled “Net Zero Enthusiasm”. In it, Editor-in-Chief Ned Cramer says
“The most significant technical innovation in architecture since the advent of computer- aided design in the 1970s, the net-zero building could positively reshape our way of life, promoting energy independence, reducing drought and carbon emissions, creating jobs. Alas, it has nothing remotely close to the smartphone’s penetration (the International Living Future Institute has only certified 21 examples)...So where’s the public dialogue, the demand? Why isn’t net-zero as familiar in our technology-worshipping culture as the iPhone? Why don’t we talk about it with as much awe as the Tesla Model S?”
This second volume of zero-net-energy (or “net-zero”, if you prefer) case study buildings is another installment in such a conversation that is actually happening in this part of the world, and it includes five awe-some examples of this new wave of technical innovation in architecture.
Volume 2 of Zero Net Energy Case Study Buildings, like Volume 1, provides a detailed discussion and analysis of a number of exemplary buildings designed and, so far, performing at zero-net-energy use over the course of a year1. As noted in the Foreword, the time between the occupancy of the Volume 1 buildings and that of the Volume 2 buildings, roughly three to seven years, saw advances in building technologies and dissemination of information about successful strategies for ZNE design. The result has been the informed development of the best approaches to the design and construction of ZNE buildings that are meeting practical requirements of reliability and affordability. Five buildings from this next round of ZNE projects are documented in this publication.
Selection of the Case Study Buildings of Volume 2
In order to be included in both of these volumes, the selected ZNE projects are required to have a minimum of one year of measured (and verified) energy consumption and energy production data, ideally on a monthly basis and broken down by category of use. Since there is no formal ZNE certification process focused exclusively on this performance criterion2, the projects in these two volumes were subjected to a careful review of their performance records and, with one exception, confirmed to be operating in a net positive mode3. (The one exception is Case Study No. 11, The Exploratorium, a unique project in many ways that is very close to ZNE performance after its first full year of operation and that is expected to achieve ZNE in the near future. See the discussion of this special project in this Volume 2.)
With the single exception of The Exploratorium, the selected building projects represent standard building types found in urban and semi-urban areas—office space, educational facility,
1 As in Volume 1, the definition of “zero-net-energy”, or ZNE, in Volume 2 is taken to be Site ZNE. That is, the amount of energy used by the building over the course of a year is equal to the amount of energy supplied by the on-site renewable energy system. This is the net-metering definition best understood by the public. There are other definitions of ZNE, most notably the nationally-adopted Source ZNE and the California building code metric of Time-Dependent Valuation ZNE. See the detailed discussion of these metrics in the Introduction to Volume 1.
2 Nevertheless, it is worth noting that two of the five projects in Volume 2 are certified by the International Living Future Institute as “Net Zero Energy”, although the requirements for such certification go beyond the energy balance and include other sustainability requirements as well as a prohibition against use of any natural gas (therefore no renewable energy “offsets” allowed in the energy accounting).
3 Net Positive means that the building is producing more renewable energy on-site than it is consuming during that year of data collection.
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Zero Net Energy Case Study Buildings: Volume 2