Originally, People’s aspired for the expansion to be performed entirely by the community and co-op members. In the end, however, the board compromised by hiring both a general contractor and a member of the co-op who is a designer/builder by trade. As an experienced residential green building designer, the co-op member helped oversee the general contractor’s work, decipher plans/specs and technical info and worked with the project manager to make changes and mid-project decisions. The general contractor had minimal experience with green building and was responsible for the framing, roof, electrical, plumbing, drywall, insulation, concrete, lifting the building/new foundation excavation and general site work. To ensure timeliness and goal attainment, the two parties met weekly and worked together for about 2-3 hours a day.
People’s made a commitment to use building materials that have the lowest impact on the environment and support the local economy. All of the wood used for the expansion was either salvaged or FSC certified and purchased from local suppliers. The timing of the expansion fruitfully coincided with the deconstruction of the project designer’s own home and sufficient market availability of certified wood thus diminishing any potential sourcing issues. Metal studs with high-recycled content were used in the walls and the siding is made of re-milled cedar telephone poles from a local recycled building materials supplier. Framing was made up of roughly 5% salvaged wood, 10% remilled salvaged wood, 80% new FSC certified wood and 5% new and non-certified wood. No carpeting was installed during the expansion and low-VOC finishes and paints were specified throughout the building.
Cob (a mixture of straw, earth, and sand) was used as an infill material on a portion of the wooden frame and cob benches were constructed in the courtyard. Reused, colored glass bottles were integrated into the exposed portion of the cob as a design feature. Recycled exterior paint and low-toxicity interior paint cover the inside and outside of the building and formaldehyde-free sheathing was specified. People’s had to compromise when choosing roofing material and decided to go with a composite material instead of metal because it was less expensive.
Over 90% of construction waste was recycled or reused. A majority of these materials were taken to a local non-profit building material recovery operation that supplies the local economy with structurally sound, reusable building materials.
The project designer notes that it was somewhat difficult at times to coordinate materials recycling, "In general, people are more apt to recycle the big materials that they perceive as having a greater impact…but there are substantially more smaller materials that really add up!"
People’s solicited volunteers to help construct the cob infill in the sun space on the south side of the building and the outdoor cob benches. Construction of the infill and benches was facilitated by 3.5 months of hands-on weekend training workshops and one classroom session on building with cob. The workshops were led by 15 experienced cobbers from Northern Oregon and Southern Washington and supplied the project with trained volunteer laborers that learned a new skill and became an integral part of the expansion effort. Total construction time of the cob infill and benches was 2.5 months.
The tremendous interest by project volunteers (approximately 1,000) resulted in volunteer assistance overflowing into other parts of the building construction as well, which sometimes proved difficult to manage. Early in the construction phase, project manager Miles Uchida found himself writing several checks a day to compensate individual volunteers for materials such as nails. This became very time consuming and, as the project progressed, he found it more efficient to contract portions of the project to a few groups of volunteers, instead of having a free for all. Miles notes that the money saved by not hiring a contractor for portions of the project was probably lost due to an elongated construction schedule.
"We did save money but organizing hundreds of volunteers took a lot of time. It’s probably a wash."
The sudden speed of the construction process compared to the drawn out pre-design process resulted in some missed opportunities for the building to increase its sustainability. For example, refrigeration heat recovery was not feasible because the equipment had already been ordered in an outdoor configuration and the manufacturer was unwilling to warranty the equipment if modified on-site. Canceling the units and re-ordering was not financially or logistically feasible during the construction process.
Construction was scheduled for 9 months but delays extended it an additional 3 months.
Keys to Success - Construction:
- Frequent and consistent interaction between the project designer and general contractor
- Organize a green building workshop around one portion of the project to solicit volunteer help and involve the community
- Salvage materials from deconstruction projects that coincide with the project
- Balance material costs by using free or cheaper salvage materials whenever feasible and specifying locally grown, third party-certified materials where new materials are needed
- Specify low/no toxicity materials
- Preference locally manufactured materials
- Use very low-impact earthen materials
- Discuss the ramifications of system modification with the manufacturer when designing integrated systems
- Be somewhat flexible in construction scheduling