HOK Net-Zero Energy Design Competition: D-breath
The net-zero competition challenged HOK’s teams to create a conceptual net-zero energy design for a building on a site in their local community. Teams were required to use HOK’s Sustainable Analysis Tool to obtain climate data, set energy use intensity (EUI) targets and estimate the size of on-site renewable energy systems required to reach net-zero energy.
The D-breath team designed a public medical office northeast of the 2nd Ring Road in Beijing, where there is a massive air pollution problem. The site sits quietly in the neighborhood of the famous Linked Hybrid residential blocks designed by Steven Holl. The team’s design received honorable mention in the internal HOK competition.
What drove your decision to create a medical office building?
We chose to design a public medical office with the aim to develop it as a prototypical urban amenity for local communities. The medical office program offered an interesting challenge for us since we had to interpret the differences between Western and Eastern medical cultures while providing an essential connection between humans and nature for Beijing residents.
How did the site affect your design?
The low-density site is adjacent to a canal and an abandoned parking area, exposing it to wind and natural light. We designed the 53,800-square-foot (5,000-square-meter) project to accommodate the building program while maintaining harmony with the surrounding landscape.
The site constraints gave us the opportunity to develop the design with maximum surface area and the ability to accommodate geothermal energy use.
What kind of renewable energy did you choose? How did you design the building to be more efficient?
Based on the climate in Beijing, we chose to design a geothermal cooling system with integrated passive ventilation. This was compatible with a larger strategy of creating a loop of building systems that achieve net-zero energy performance.
The building form was created to optimize energy performance. An intelligent, charcoal-brick framework and infill system incorporate smart modules that are based on optimal orientations to utilize the sun and wind. Solar heat is harvested for energy exchange and natural ventilation strategies are fully integrated into the structure and envelope.
How did the HOK Sustainable Analysis report impact the design?
This tool helped us evaluate the sustainable design strategy in depth. It was interesting to observe how energy inputs vary greatly within the program itself. We compared our analysis with the Revit climate analysis tool and decided to combine the basic principles with our real-life experience to create our design.
What was your favorite part of the design competition?
In this competition, we considered how to address an ubiquitous and serious problem in China – air pollution. With “D-breath,” we focused on creating a net-zero carbon structure that actually purifies and filters the polluted air, helping to provide a better breathing environment for Beijing residents.
While we focused on finding a solution to a local problem, D-breath, which features an infill system tailored to the specific geographic location to maximize the performance, can be located anywhere in the world.
View all of the project images on Flickr.