The net-zero energy building challenge: Who will be next?
In the ever-evolving sustainable design and construction arena, some owners and project teams are setting their sights on a challenge that seemed improbable just a short time ago. That challenge? Creating net-zero energy, or ZNE, buildings. These buildings produce as much or more energy as they consume each year.
While ZNE buildings currently make up a very small fraction of the overall green building market today, it’s clear that this new frontier in sustainability is gaining traction.
LEED has proven to be a logical baseline for net-zero energy strategies; according to an article written by USGBC, half of ZNE buildings in the United States (15 of 32) are also LEED Gold or Platinum certified.
As DPR pursued “darker” green strategies for our San Diego and Phoenix offices, we chronicled our journey — as both the owner and builder — in “The Path to Net-Zero Energy” case study.
Our project team completely transformed a 34,000-square-foot, 25-year-old industrial building into DPR’s San Diego regional office. It was the city’s first commercial office to achieve both LEED Platinum certification and ZNE status. Through an online dashboard (which five of our offices currently use), building occupants monitor and compare energy usage and production. The energy use intensity, or EUI, is 16.2 kBtu/SF.
We created a net-zero energy office model that maximized existing features to yield a 10-year return on investment. This was a launching pad for our net-zero projects to follow.
DPR’s LEED Platinum Phoenix regional office became the largest building in the world to achieve net-zero energy building certification from the International Living Future Institute’s (ILFI) Living Building Challenge. To be certified under the Living Building Challenge, projects must meet a series of ambitious performance requirements over a minimum of 12 months of continuous occupancy.
Our project team purposefully chose a building that was nearing the end of its intended lifecycle in a redeveloping area. In 10 months, the team researched, designed, permitted and transformed the space into a highly efficient, modern space.
Using our experience with our San Diego office as a starting platform, the Phoenix office includes Solatubes®, shower towers, a solar chimney, Big Ass Fans®, a “vampire” shut-off switch and photovoltaic-panel-covered parking.
Lessons learned from renovating our own offices into ZNE spaces include:
- Contrary to a common misconception, LEED and net-zero energy can save resources, whether through upfront incentives or through long-term operating costs;
- “Limitations” of existing buildings can be leveraged as opportunities;
- ZNE can be achieved in both temperate and severe climates;
- When implementing new techniques or technologies, treating the space as a “living laboratory” allows for adjustments for the life of a building while educating the rest of the community; and
- Simpler can be better (new, high-tech solutions combined with established strategies).
The LEED Platinum, 50,000-square-foot David and Lucile Packard Foundation Corporate Headquarters in Los Altos, Calif., replaced the DPR Phoenix regional office as the “world’s largest ILFI-certified net-zero energy building.” That building was DPR’s first ground-up net-zero project.
The journey ahead
Experience has proven that every journey is different, especially when it comes to complex projects or ambitious goals. We’re happy to share more lessons learned with those who are interested in accepting the net-zero energy challenge.