This seven-part blog series profiles a new prefab development in San Francisco's SoMa neighborhood—a LEED Platinum-targeted building containing 23 "micro-studios". Built in a California factory in a month and assembled on-site in just four days, these 300-square-foot units are paving the path to a new approach to prefab—and to small-space city living. PART TWO: Prefab Q&A
The apartments at 38 Harriet Street in SoMa have been a long time coming. Four years ago, Patrick Kennedy, the founder and Principal of Panoramic Interests, an urban infill developer based in Berkeley, California, began developing the concept for prefab, space-efficient dwellings. When the time came to pick a construction company, Kennedy turned to Charles Pankow Builders, a business known for its innovative construction methods and high-profile projects throughout California. Here, Kennedy and Wally Naylor, Principal in Charge for the Harriet Street project, give some backstory; discuss the pros and cons of prefabrication; and predict what it will take for wider-scale adoption of factory-built buildings.
How did the idea for the micro-units at 38 Harriet come about? What inspired the project?
Kennedy: The fastest growing demographic in America is the single person household, and nothing was being built, it seemed, to address its needs. Moreover, habits and practices of city dwellers, especially those in cities like San Francisco, have changed the expectations and preferences for housing. Location, convenience, and proximity mean a lot more to most San Franciscans than space.
Were there any precedents for this project, in the U.S. or beyond, that you looked at as you developed your concept?
Kennedy: There are many examples of small space living in Japan, Europe, and places like New York. The ideas for small space living come from many other sources as well, like boats and backpacking.
However, I am not aware of too many new developments in the U.S. that have tried to design a small modern urban space from scratch and put a bunch of them together in one building. Cubix, in S.F., is one exception. We studied it very carefully and learned quite a lot. For example, it's important to have a big kitchen sink and lots of storage.
Why did you choose the prefabrication process for 38 Harriet specifically? What other construction techniques did you consider?
Kennedy: We looked at conventional wood frame construction, which is about the same price. But we concluded that this was a good type of project for prefab, since we wanted simple, repeatable spaces, with a good rental market. Mainly we just wanted to see if it would work.
What are the key benefits to building prefab, from your perspective?
Kennedy: Three words: No Change Orders. Also, much better quality—the soundproofing in these units is incredible, better than any luxury high rise in the city, I'd bet. Also, better scheduling and a more predictable outcome.
Naylor: A factory environment provides for greater quality control with less climatic variations, and the prefab process enables us to cut our construction time in half, from 34 to 17 weeks. It’s cleaner, greener, and quicker. There's less site disruption and noise impact to the neighborhoods; it can be fabricated to LEED Platinum standards; and the site work preparation and prefabrication can occur simultaneously. In terms of cost, since this is the first prefab project we've done on an urban infill site, with a limited number of units, we have yet to realize all of the potential cost savings of prefabricated versus site-built. But we do believe economies of scale can be achieved with a larger number of units.
What are the challenges, limitations, or downsides to prefab construction, in general or as relates specifically to this project?
Kennedy: The planning was like the construction equivalent of a moon shot. But having done it successfully now, it will be much easier, faster, and cheaper going forward.
Why did Panoramic Interests select Pankow as the builder?
Kennedy: Pankow had experience in innovative construction processes, and was committed to exploring this type of prefab further. They gave us their best people for the planning and execution, resulting in a near flawless construction process. They also provided deep resources and financial stability.
Why did you choose ZETA as the fabricator?
Kennedy: ZETA understood the potential for multi-story prefab and had incredible attention to detail in getting this right the first time out. They had a solid team and a terrific project manager, Taeko Takagi.
What do you think the role is for prefab in the future of the construction industry?
Kennedy: It certainly has a future in high-cost areas like San Francisco and for any project that has economies of scale.
Naylor: There is potential for this product type for student housing, senior living, and urban infill multi-family projects with a high degree of repetitive designs.
Do you think prefab has the potential to transform the industry?
Naylor: Prefab components are already widely used in the construction industry today. We are beginning to see more prefabricated systems and buildings in a variety of different market sectors. As on-site labor rates and on-site environmental regulations rise, there will be an increased tendency to prefabricate many components off-site in a controlled factory environment.
What do you think it will take for wide-scale market adoption of prefab processes?
Kennedy: More successful projects like—cross your fingers—this one. We'd love to build another dozen of these if we had the land.