The idea came from a friend in Mountain View, who got her neighbors to have the work done at the same time, Green Acres residents said.
The homeowners worked with La Honda/Redwood City contractor Anderson-Niswander Construction Inc., which specializes in seismic work and had done two prior group upgrades in Mountain View, Sherry Niswander told residents.
"Discounts are possible due to economies of scale and undertaking consecutive retrofit jobs in the same general neighborhood. Tools and equipment can be moved directly from one house to the next," she informed residents by email.
Each house was pre-inspected. Because residents had the homes done in groups of four, the inspection price was dropped to $100 per home. The fee went toward the cost of inspections and written reports.
By March, 10 residents chose to have the work done — sufficient for the discount, homeowner Craig Mohr said.
Most of the tract's homes bordered by Maybell Avenue, Arastradero Road, Coulombe Drive and Georgia Avenue were built in the 1950s. They are bolted or nailed to the foundations, but don't meet today's codes, he said.
Bigger bolts, shear pins and sill plates were added to his ranch-style home. An engineer explained that wood-frame houses, if properly bolted, aren't going anywhere in an earthquake, he said.
Mohr said he paid $5,200. Without the group discount, he would have paid $7,800, he said.
He is happy with the work and increased sense of safety. The homes will also do better on resale, he said.
"I think some people will be sorry they didn't do it. In a good shake, their house will slide a little bit," he said.
A small flurry of email exchanges among the neighbors included answers to different questions several residents had researched independently — reports from neighbors elsewhere who had had similar work done by the contractor; checking the Better Business Bureau; verifying that Palo Alto did not require a permit for the work; a comparison of estimated costs with costs of earthquake insurance; and the experiences of people in Northridge, Calif., who had similar work done before their earthquake, homeowner Ruth Satterthwaite said.
"Anderson-Niswander kept us updated on the number of inspections, reports and contract commitments until we reached the magic number of seven by March 22, at which point they began putting together the construction schedule and the individual contracts with the 20 percent discount.
"It was essentially painless for us as customers. … It was, of course, noisy at times, especially when they were drilling into the concrete," she said.
The Satterthwaites paid slightly more than $2,000, including the inspection fee, she said.
"A lot depended on whether the foundation was already bolted or only nailed and the general condition of the foundation itself (existing cracks or dampness)," she said.
A few of the existing bolts under Satterthwaite's home had started to rust, and their placement near the corners did not meet current code, she said. But she also received peace of mind, she said.
"The foundation was 'robust' and 'in excellent condition for its age,' which was more reassuring than we might have expected."
Satterthwaite added that it was valuable to exchange questions and research results before making final decisions, especially since people thought of different areas of possible concern.
"As a neighborhood, we have already encouraged disaster prep, although of course there are some better prepared than others. We still have our fair share of denial among some of our neighbors.
"How will we reap safety benefits? Maybe we can better answer that after the next earthquake," she said.
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