Tech delivers cost-effective response to Title 24
According to the U.S. Energy Information Administration, last year, 40 percent of energy consumption in the U.S. came from residential and commercial buildings, a number which needs to be sharply corrected as we work toward more sustainable future. Title 24, the building energy efficiency standards in California which mandate that all residential buildings must be zero net energy
(ZNE) by 2020 and commercial buildings by 2030, is one of the notable efforts being made to serve this correction.
To catalyze ZNE and zero net carbon construction under Title 24, Milpitas, Calif.-based View Inc. recently collaborated with a number of other local design and construction companies to create a blueprint structure to empower architects to meet these rigorous standards at an affordable cost. Located at 415 Mathilda Avenue in Sunnyvale, Calif., “the Mathilda project” demonstrates the pivotal role energy-efficient technologies will play in making this aspirational future a reality.
The Challenge
In 2014, View teamed up with Studio G Architects Inc., San Jose, Calif.; Integral Group, Oakland, Calif.; Sharp Development Co., Portola Valley, Calif.; EBS Consultants, San Francisco; and Hillhouse Construction, San Jose; to create a cost-effective and economically viable blueprint for other commercial structures aiming to go ZNE. Together, we renovated a 40-year-old, 34,875-square-foot facility into a vibrant office space that requires zero net energy.
Renovating a building constructed in a different era is a challenge in of and itself, but transitioning it to a ZNE building compounds this challenge. One task that made this more difficult was the need to aggressively expand the number of windows throughout the building. Since it was previously used as a racquetball facility where windows were not needed, the team had to add 86 new windows, increasing from a 5 percent window area to approximately 40 percent window area. This glass expansion would increase the building’s solar load, requiring a novel solution to maintain a highly efficient building skin.
The Solution
To achieve the ZNE objective, the team used an integrated package of emerging and mature energy-efficient technologies. The implementation took nine months to complete.
The cornerstone technology was dynamic glass from View. Unlike traditional glass, View Dynamic Glass intelligently changes tint in response to the sun’s movements, weather patterns, building design and user preference. The result is a window that enhances occupant experience, maximizing natural light and providing unobstructed views while reducing heat and glare. In a typical installation, View Dynamic Glass reduces annual HVAC and lighting energy consumption by as much as 20 percent, and HVAC peak load by 25 percent.
To provide the maximum free lighting, cooling and heating possible, we installed dynamic glass across the east, south and west façades. The unique variable tinting and solar heat gain characteristics of dynamic glass allowed us to drive more performance out of the other advanced and mature technologies. These included advanced skylight designs to maximize daylighting; extreme-insulation and night-flushing to provide passive cooling; and dynamic solar-gain control to provide passive heating. By using this “passive first” approach, the team saved energy, while simultaneously downsizing expensive HVAC, lighting and rooftop photovoltaic (PV) installations, substantially offsetting the net installation cost of the other efficiency measures.
The team also installed the minimum HVAC system required by code (ventilation only), with all other temperature control provided passively. This cut 80 percent of the HVAC energy and maintenance costs, and 80 percent of the capital costs. Once the team squeezed as much performance as it could out of passive systems, the team deployed the best-in-class active energy efficiency measures to meet the remaining requirements of the building (e.g., LED lighting and plug-load management). This minimized total electrical load, enabled the smallest renewable power system possible and further reduced first-costs of the installation.
The Impact
The Mathilda project succeeded in its goal to become an affordable commercial design that meets ZNE and zero net carbon guidelines, and can easily be replicated in most California commercial and residential buildings. Notably, the project delivered immediate payback and net-positive cash flow.
Led by View Dynamic Glass, the integrated package of technologies achieved a return on investment 20 percent higher than for conventional (non-sustainable) construction projects, proving the strong economic value proposition of this approach will help drive replication across California. As a demonstration of its impact, the Mathilda approach has already spawned clones. The building was also able to quickly attract a new tenant.
The teams involved believe this project will serve as a case study for years to come. It not only provides a cost-effective, profitable renovation design for the fast-approaching NZE era, but also underscores the construction industry’s ability to thrive in a progressive policy environment.
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Brandon Tinianov is vice president of business development at View Inc., Milpitas, Calif., and is on the national advisory council of the U.S. Green Building Council. For more information, visit viewglass.com.