Looking Back at a Greenhouse Built Twenty Years Ago... / by Michael Cobb




Joyce Gross was kind enough to share with me some recent pictures from her wonderful garden in San Leandro.  She inherited a greenhouse I designed and built over twenty years ago and she graciously sent me some recent pictures of the building as it stands today, newly renovated. A thank you to Michael McGee as well for doing the much needed repairs. It felt like an appropriate time to revisit the project.  If you get a chance, check out her blog too.  

It was a turbulent time in my life.  I still hadn't taken the architecture exam and wanted desperately to finally design and build something meaningful.  This little project, so modest in scale, remains large in my mind.

At the time, mass customization hadn't taken off yet. I remember driving over to the Simpson Strong Tie plant a few miles from my house in San Leandro. I had a floppy disk with a DWG file on it for the plant manager. They didn't usually work with other people's files but if I wanted to bring it over, he would try to use it to cut out what I wanted.

San Leandro use to be called Cherry City before it became an industrial center and the Broadmoor area, where I grew up with my Dad, Grandmother and sister, still had a few larger lots with vestiges of this older agrarian time.  Our backyard still had a concrete slab where the barn use to be. The barn was before my grandmother - a school counselor and music teacher  - got ahold of it. She kept many of the old trees and added others.  There were cherry, lemon, orange, persimmon, plum, peach, tangerine, fig and apple trees all in her backyard.  I'm certainly grateful for the "advances" in our environment today, but looking back that situation seemed "abundant."

I haven't seen the neighbor, who hired me to do the greenhouse, in many years. He was an interesting man.  A physicist who worked out in Livermore, he was very open to experimentation.  He use to joke that he didn't understand why architects didn't treat building more experimentally.  "Why don't you build a prototype that could be rebuilt after we see the flaws?" he would ask.

I've always liked that observation of his. It exposed a basic difference between architecture and so many other technological undertakings.  Cars, airplanes, bicycles and other devices have such explicit functions but architecture in many ways is constantly being adaptively reused.  It not only tends to exist in time for longer than these other things, it also can change its function over time. It is not unusual for the hypothesis of the experiment (e.g. "let's build a one bedroom house") to change over the span of this experiment we call construction.  So many buildings get additions or remodels over the course of their lives. Cost aside, this in itself, tends to discourage a sense that a rebuild would improve things substantially. You get one crack.

For whatever reason stars aligned.  The neighbor hired me to build a greenhouse for his orchids. I was coming off a painful divorce and wanted a physical task that would keep my mind and body occupied.  My grandmother had a bunch of old panes of glass from a disassembled greenhouse that use to be standing in her backyard so I designed a greenhouse around adaptively reusing these old panes of glass.  We reused all her old glass in this greenhouse design.

Greenhouses are simple and elegant structures comprised predominantly of structure, "stops" (to hold the glass in place) and the glass itself.  Because the budget was so tight I designed an assembly where both the structure and the glass stop were derived from a single 2x4. Similarly, the CNC metal plates cut by Simpson Strong-Tie allowed 2x2 pieces of wood to span the entire width of the greenhouse.  This created a branch-like clerestory that felt sympathetic with a house for orchids. It still allowed good penetration of  sunlight.






































Instead of wiring the greenhouse with electrified window operators we used passive solar "autovents" that utilized a mineral wax piston that expanded without the use of electricity.  During the hottest part of the day, the skylights open on their own. In the evening the skylights close and help keep the plants from freezing during the night.




The whole thing was a function of economy.  So often when this term comes up in design it is  associated with "compromised beauty."  "If only we had a larger budget, the design could be so much nicer."

For me, the design experience of this greenhouse stands as a contrast to that logic.  The reasons are hard to articulate but I keep it in mind when I'm up against tough economic design constraints. Certainly there are flaws in the design and the limited budget did require working with crooked material and thin glass, but when I consider the more conventional work I've done, it seems to me the ingenuity that the budget necessitated generated something other work might have lacked.

A big thank you to Joyce Gross who has made such a wonderful backyard environment of which this greenhouse is but one part and for sharing her shots with me.  Check out her blog to see some beautiful plants a few more shots of the greenhouse.