Eugene has one of the highest populations of unhoused people per capita in the country. Our goal in creating this community is to provide people with shelter by designing micro-units that can be quickly assembled and are made out of inexpensive, but durable materials. In this project we are striving to create community for people who truly need one. To do this we hope to create a community focus on gardening and farming.
Program and People
Kengo Kuma: Yusuhara Town Hall
This case study served as our inspiration for our construction method. In the Yusuhara Town Hall, Kengo Kuma designed a structural system that used 4-post columns, which allow for beams to pass through them. The flexibility of this structural idea appealed to us as we were searching for a system that allowed for modularity and adaptability.
Shigeru Ban: Halsey Nine Bridges
We were inspired by this case study by Shigeru Ban. Ban creates a structure that blends a grid shell structure with dendriform columns. The quality of light and the beauty of the structure is very inspiring.
The site plan development will occur in phases as shown in the figure below.
The build will also be done in three phases: 1. Micro unit + Platform, 2. Secondary Roof and 3. Walkways + Micro unit expansion, shown in the respective order in the figures below.
- Our micro-units consist of four post columns and prefabricated insulated panels
- The columns are built with 2x2s
- The panels consist of 1/2″ Plywood sheets on the interior, EPS foam insulation in the center, and T1-11 Plywood siding on the exterior
- Shown on the right are different variations of prefabricated panels that make up our micro-units
The structural analysis was done on top of the parametric model built in Grasshopper using Karamba 3D.
Three different loads are applied to the model:
- Dead loads: gravity load from mass applied to the whole structure in -z direction; additional dead load applied on the first floor rafters as uniform live load of 20 psf.
- Live loads: applied to the floor as uniform shell load, equivalent to 30 psf (for residential use)
- Earthquake loads: applied on the mass of the structure in x and y direction (equivalent to 15% of the weight of the structure)
The material used is Douglas Fir-Larch No. 1 dimensional lumber, defined as an orthotropic material in Karamba. The cross section for column was made from 4 nos 2×2 lumber while the shell is an inch DF-L ply.
The utilization rate of the material is up to 40% (compared to reference values) in this model, the structure should be okay. However, with the addition of wind load, the structure warrants a more granular analysis by checking all the elements of the model.
- Our community building is inspired by the Shigeru Ban precedent shown above
- This precedent inspired us to write a form-finding grasshopper script that created a grid shell and dendriform column structure
- The community building is split into two parts:
- A double-height space meant for community gathering and large meals
- Services for the community at the back of the building
- The building is optimized to let in as much light from the south as possible
- We think of the system as a hybrid of grid and dendriform structure. The grid provides a shell-like mesh for the flat roof while the dendriform structure passes the forces from the roof to the column in a more distributed fashion, thus allowing the use of smaller members.
- This can also be thought of as a flat roof with a curved capital on the post.
- These are showing a Karamba analysis of our community building structure.
- What we found is that we will need more lateral bracing in the structure moving forward, as there is torsion in the structure owing to the asymmetry in plan of the outer enclosure.
- We may also have to consider making the roof more lightweight