What does it take to design a net zero emissions office building? Because few of our clients are currently considering carbon neutrality in their projects, an HOK team — with help from some wonderful friends — is designing one through a series of virtual charrettes.

In response to Architecture 2030’s challenge to the global architecture and building community, HOK has committed to designing all buildings to be 100 percent carbon neutral by 2030.

The idea for the charrette is the brainchild of HOK Chairman Bill Valentine, who wants the firm’s people to gain the knowledge and experience required to design zero emissions buildings. This vision is being turned into reality under the guidance of Firmwide Sustainable Design Director Mary Ann Lazarus and a diverse team of designers and consultants.

The challenge is to create a zero emissions design for a typical office building, which the team has defined as a multi-tenant, 200,000 gross-square-foot building that is 3-4 stories and built with 95% rentable-to-gross efficiency. Other goals are for the building to be affordable (10-year payback); marketable; buildable using today’s technology, materials, systems and codes; sustainable; and flexible. The design is being created on a site in midtown St. Louis with valuable market input from local developers Green Street Properties.

For this charrette, the team is defining a zero emissions building as one that produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources in a year.

The team is using building information modeling (BIM) to create a conceptual design driven by performance metrics. The deliverables will include a comparative analysis to a typical St. Louis office building built to code, as well as 10- and 25-year life cycle cost analyses.

Dr. Dayna Baumeister of the Biomimicry Guild is ensuring that the team looks at more than just reducing energy use while using life’s principles to inform the design strategy. “We need to consider what life has learned to do to adapt and thrive in this specific place,” she said. You can listen to her talk about applying this approach to the project’s St. Louis site here: 

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

David Eijadi, FAIA, of The Weidt Group has committed his firm to providing quantitative guidance toward a zero emissions solution. “From pre-design, through virtual design and into building operations, the calculations matter,” he said. “We cannot guess our way to zero and have a real solution.”

To create the net zero design, the entire team will meet virtually for several design charrettes — with lots of smaller work sessions in-between — over a two-month period. Team members hope to complete the design and process documentation by the end of August.

The Team

The team for the first design session included:

Green Street Properties: Michael Clark and Phil Hulse (developers)

The Biomimicry Guild: Dayna Baumeister (biologist at the design table)

The Weidt Group: David Eijadi, Prasad Vaidya, Chris Baker and Vinay Ghatti (energy/daylight modeling)

HOK: Bill Valentine, Bill Odell, Alan Bright (design/architecture); Tim Gaidis (design/sustainability); Dave Troup (design/engineering); Gerry Faubert (integrated design/engineering); Mary Ann Lazarus, Colin Rohlfing (design/sustainability); Jeff Sanner (design/Ecotect modeling); Tyler Meyr (design/planning); Frank Kutilek (cost estimating)

The group will leverage these interconnected disciplines and link the building’s interdependent systems with an integrated design that creates a truly multifunctional, zero carbon solution.

Session One

For the first zero carbon charrette on June 26, the team assembled virtually in Advanced Collaboration Rooms in HOK’s St. Louis, San Francisco, Toronto and London offices. Other participants joined via WebEx. The technology in these ACR rooms enabled team members to see and talk to each other in real time and to sketch together on virtual white boards. As the team entered this uncharted territory, there was a palpable feeling of excitement and nervous energy in the air.

“My focus for the past 15 years has been on sustainability and whole building design, so this is the summit for me, the ultimate test,” said HOK Director of Integrated Design Gerry Faubert, who is based on Toronto.

Early in the session, the team agreed that documenting the process would be nearly as important as the actual design solution.

“The idea is to identify what we can do here while also developing a replicable process that can be applied to any site,” said Tim Gaidis, Sustainable Design Practice Leader in HOK’s St. Louis office. “We’ll highlight items that need to be customized for specific locations.”

“I think we’ll learn so much about how to use an affordable, simple process to get to zero carbon that we’ll be able to tackle any site,” added Valentine.

The team finished the first session armed with four different building schemes to explore before the next full-team charrette on July 31.

“It was an amazing day together,” said Lazarus. “This was a terrific example of an integrated team at work, mining everyone’s insights. As an example, we saw energy and Ecotect modelers challenging the ideas of senior designers. There were no silos by function or role.”

“It was great to see the team keep checking ideas against their local marketability so we can eventually compare the design to conventional buildings in the market,” said Green Street Properties Principal Phil Hulse.

Next Steps

To prepare for the next charrette, team members are running multiple models to identify the most important variables, creating baseline modeling and massing options, conducting a planning design parameter study and developing cost models for each scheme.

On July 23, several team members will meet in The Weidt Group’s offices in Minneapolis for a design charrette focused on balancing the equations for energy performance across multiple building systems: architectural, mechanical, electrical and controls. The group will bracket the ways the team can meet the design objective.

During the July 31 session, the team will select the preferred scheme and further refine the concept. The focus will be on optimizing all passive solutions before pursuing integrated active systems.

“The process so far has already demonstrated how hard it is to not fall into our natural design patterns,” said Lazarus. “We have to challenge ourselves to be driven by performance at each step.”