The Net Zero Energy Buildings of Tomorrow, Today
With advances in engineering and energy procurement, the possibility of net zero energy buildings is more fruitful than ever.
Published March 1, 2011
By Jamie Kass
Academy Contributor
The green building community has made significant progress in designing and constructing energy neutral or ‘net-zero energy buildings’ (nZEBs), but these buildings are rare and are generally relatively low-intensity-use structures under 15,000 square feet. Now the community is developing strategies to scale up and to make the buildings more commonplace within the industry. On January 25, 2011, three speakers presented inspiring projects that are achieving new levels of sustainability in a challenging marketplace. They provided insights into metrics of success, best practices, trends, and prospects in the realm of low/net-zero energy building development.
Paul Torcellini, a commercial buildings researcher at the National Renewable Energy Laboratory (NREL), described the goals and vision that guided the design of the NREL–RSF (NREL–Research Support Facility) building. NREL preferred a design-build bid that would meet as many goals as possible from NREL’s list of priorities.
The energy goals held particular significance. According to Torcellini, the success of the NREL-RSF design-build process was that it provided performance-based guidelines rather than design solutions—thus allowing the design-build contractors to be creative and develop their designs within the performance guidelines. The resulting building, which represents a great step forward in the net-zero energy realm, was constructed with the budget typical for a regular office building. Most of that budget was spent on design and modeling rather than on construction.
Human Behavior: The “Final Frontier”
The value of such a front-loaded design process was echoed by Philip Macey who leads Haselden Construction’s sustainable building division. Macey noted that the design form and function of the NREL-RSF were modeled to meet the energy goal. This required designing the building’s components for synergistic roles and multiple uses. Macey explained that designing with a ‘multi-purpose’ concept for a building’s elements was not new: architects have been applying the same idea to work within space constraints, but the difference this time was that the constraint was an unequivocal and precise energy savings goal. Macey articulated that being goal-oriented from the beginning was crucial to maintaining control, achieving those goals, and reaching project completion within budget.
Bert Gregory, Chairman and CEO of Mithun, expanded the discussion to neighborhoods, which can offer benefits unavailable to single buildings. For instance, integrating water systems is better achieved at the district scale. Gregory outlined several sustainable urban design projects where the goals varied from carbon neutrality, to water neutrality, and, in the case of Mithun’s Lloyd Crossing project, to having a neighborhood that has an environmental footprint equivalent to that of a native Northwest forest by 2050. The Lloyd Crossing project aims to transform the Lloyd district study area, a 35-block area in Portland, Oregon, into an environmentally and financially sustainable community.
In all his examples, the goals and performance metrics were stated at the outset and were followed by the development of strategies to achieve these goals within constraints such as zoning regulations, electricity demand reduction capabilities, renewable energy generation capacity, resource recovery, governance models, financing, and human behavior. According to Gregory, when it comes to achieving the energy saving goals of demand-side management initiatives, human behavior is the “final frontier.”
Also read: Green Buildings and Water Infrastructure
