Zero net energy (ZNE) structures are environmentally sound and cut energy expenditures significantly. Few would deny that both of those are worthy goals. There are challenges to the future of the sector, however, on both the technical and social fronts.
On the social side, proponents must help people understand such issues as how much of a cost premium – if any – there is for creating these structures and what behavioral changes will be necessary to achieve the net-zero goal. In the technical realm, building control remains an issue.
Who’s In Control?
There is no silver bullet to achieve NZE. Rather, it is an accumulation of many incremental changes. Therefore, control of each of these advances as well as the overall coordination of how they related to each other is important. The Continental Automated Buildings Association recently conducted a study entitled “Zero Net Energy Building Controls: Characteristics, Energy Impacts and Lessons.” The press release accompanying the study said that one of the findings was that zero net energy buildings “have some controls problems. The reasons were not based on any specific product, but rather on the process to ‘get it right’ and installation issues.”
In response to emailed questions from Energy Manager Today, Rawlson O’Neil King, CABA’s Communications Director, wrote that control of building elements must be a priority. “Our report finds that from both the design team and the operators’ perspective, useful solutions lie in an increased need for the controls contractor and the building operator to be more actively engaged with the design early, during commissioning and after occupancy. The majority of design firms attributed HVAC, lighting and plugs each with having a greater than 15 percent impact on the energy savings, so the success of the control of these systems means the success of the building owner or operator’s energy objectives.”
The Public Must Understand
Other challenges to the creation of ZNE buildings are public perception and behavior. Eliza Clark, Anderson Corp.’s Director of Sustainability, suggested in a story at Triple Pundit that “a powerful fallacy” exists that green and net zero homes are expensive and require occupants to adopt significant lifestyle changes.
The reality is more nuanced and calls for the public to be educed about the technology by architects, buildings or product suppliers, Clark wrote. She added that the category only will gain traction if it is enabled by officials who write building codes and control municipal infrastructure.
Some behavioral changes will be necessary. The younger generation is more apt to accept behavioral change, wrote Juliet Grable at Building Science. This can be accelerated by clearly explaining the benefits of NZE homes. Grable discussed a nice trick that buildings and developers may use to drive shoppers to buy NZE homes. Davenport suggested that it may be a good idea to incentivize buyers:
For example, builders could offer a cash bonus to homeowners if the sum of their first year’s electricity bill falls under a specified target. By then, the behavior will have become habit.
Cost, of course, is a huge issue. Grable wrote that Davenport said that most people won’t accept a 10 percent markup premium in construction costs. The limit for most buyers is 2 percent. Thus, that is the target that builders must hit.
Despite the challenges, ZNE buildings are making profess. This week, The Fifth Estate reported that The Green Building Council of Australia will introduce net zero certification for buildings beginning next year. The rating will before energy, carbon and water performance and means that the country is joining Canada and South Africa in ZNE building labeling.
Progress is being made elsewhere as well. CABA’s King wrote that work is ongoing on control issues. “Because the report finds that most zero net energy buildings are being operated in public sector, often at universities, I can offer conjuncture that a tremendous amount of fine-tuning is most likely taking place on controls. Often, such buildings are viewed as experimental showpieces by public institutions and in universities, are also often used for academic research and industry benchmarking.”