After years of collaborative design and research, we’ve finally broken ground for the Seed Office Headquarters. Here 7-year resident and master mind of the project GPaul meets with concrete contractor Kevin to review the floor plans one more time before bringing in excavation machines.
Just beyond the meeting of the minds you can see the building site, the lull and quiet imminently to be replaced by the head-spinning change and activity of construction.
Looks like our frenetic anticipation might be rubbing off – here’s Sean, concrete worker, laying out the building footprint.
After coming to an understanding about the foundation plan and execution thereof, we gave the okay to get the machines rolling.
As the default project coordinator, this is both a terrifying and triumphant day for me, as witnessed below.
About a day into the excavation, Kevin frantically called me out to the site. They’d hit bad ground, i.e. spongy, non-compactable soil – not the kind of thing you want to put a 6,000 square foot seed office slated to house our business, the livelihood of our community, on. I was told I needed to call a geotechnical engineer immediately, which I soon learned was an engineer who evaluates your site soil and tell you what your options are for building on it.
It turned out that our options were to a) re-design the foundation as a “floating slab”, which entails laying a grid of rebar and pouring the slab thick enough so that shifting ground underneath the foundation wouldn’t effect the structural integrity of the building, b) scrape off the spongy soil till we hit good ground, or c) find a new building site. The later most of those filled our hearts with dread, as we had already errected a warehouse adjacent to the site to be part of the “seed plant”, and had designed our building precisely to fit in this site, with passive solar components designed off the solar orientation and coordinates of the site. We contemplated option a and b, and eventually sided with option b, as we could use some clay mined from the site and crushed recycled concrete debris to bring the site back up to height, as opposed to the steel and concrete of the floating slab, which has a much higher embodied energy.
Below you can see the lighter-colored dirt being scraped off the site to reveal a deep red clay underneath.
Once the “bad ground” was all scraped off, we begun bring clay back in, compacting it in lifts, and adding the recycled concrete to be compacted on top of that.
Although the spongy soil and lots of rain really slowed down the timeline, here we’re almost ready to begin the foundation.