Seed Home 2 Production

Production Engineering

OSE's value proposition is to enable public production - meaning that we design our products to be built by the user as much as possible. This is responsible, because it encourages a deeper level of product understanding on the part of the user. This in turn leads to improved lifecycle stewardship, and the potential of lifetime design.

Public production engineering is defined as the production method that involves the user in production.

The public production engineering route also implies that the user will need some support. The level of support determines the level of value exchange between the user and OSE. The value exchange determines cost of support. Thus, understanding costs starts with understanding of the production engineering, so that the value exchange is fair.

One must delve into the details of the build method to determine:

1. Build complexity - build complexity should be minimized
2. Build difficulty - build difficulty should be minimized, which we do by modular design and human-centered design. We assume that people will be doing the build, and we want to limit the use of heavy equipment (unless such equipment is easily accessible at low cost). We thus design materials handling to be such that any part is under 100 lb of weight per person, and no more than 150 lb for 2 people, in general.
3. Effort

Assessment of Weights

• 2x12 lumber - 66 lb
• P2 anchor - 30-80 lb (from 5-10', with 1-3 helices)
• Total Panel Weight - 139 for regular and 211 for window:

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It is reasonable for a person to make and stash panels. Installing them is harder, as it requires more control over positioning, rather than simply carrying. Installing panels on a second floor is even harder - it would require scaffolding to the second floor, or a forklift, or jigging so the panel can't fall such as stops on the outside wall.

Alternately - a crew can be hired for wall building.

Labor Cost

Walls

• Assume it takes 2 hours to build one panel. For a square house - that is 32 panels. This would take 8 weekends, 4 panels per weekend. The job would be easy if the work were to be done in a well-organized workspace - number of work horses, everything staged out together for assembly-line-like procedure.
• Wall labor crew would cost 32*$50= $1600.

Floor

• Piles are included. Detail of what is after the pile is critical - to make labor easy.
• For installing a square platform of 13 2x12s and one 4x6 down the middle ([1]) - 116 lb (https://www.engineeringtoolbox.com/green-kiln-dried-pressure-treated-lumber-weights-d_1860.html)
• I would do 2 of the 2x6x16 instead for easier work, screwing them together, and $10 cheaper, except for added labor.
• The piles would need nice self-support brackets for the foundation on top, so no lifting into place is required, but only dropping hte lumber into place so the work is as easy as moving a 2x12 into place.