52.3°
By Gregory J McFann, Building Official
City of Alameda Planning & Building Department
For those who remember the 1989 Loma Prieta earthquake, a lasting image for many was the collapse of numerous apartment buildings in the San Francisco Marina District.
This relatively small area of San Francisco suffered the collapse of seven buildings, and after the dust had literally settled, an additional 35 buildings were found to be beyond repair, while more than 150 buildings had been damaged.
The 1994 Northridge earthquake left us with the visual image of whole apartment buildings collapsed onto the cars parked on the ground floor. As a result of these earthquakes, many buildings over a wide area suffered significant damage. A high percentage of the collapsed or destroyed buildings in both the Marina District and in Northridge shared a common feature - they fit the definition of a "soft-story building." Soft-story buildings can be found all over Alameda, and for the most part, we don't give them a second thought. A soft-story building is a multi-story structure in which the ground floor has wide doors; large unobstructed show windows and other large openings in place of shear walls that could provide needed stability, including parking spaces. A typical soft-story building is a several-story apartment building located over a parking garage or a series of retail businesses.
So why, might you ask, am I writing about soft-story buildings? They are vulnerable to collapse in moderate to severe earthquakes in a phenomenon known as Soft Story Collapse. Soft-story failure was responsible for damaging nearly half of all housing units that became uninhabitable following the Loma Prieta earthquake. In Alameda, we have a significant, yet undetermined number of soft-story buildings. In the interest of protecting the residents of Alameda and Alameda's housing and retail building stock, the Planning and Building Department will ask the City Council at a meeting in the near future to consider a soft-story retrofit ordinance.
A number of California cities have looked at adopting their own soft-story ordinance, and two of our neighboring cities have them in place. Fremont has adopted an ordinance mandating the retrofit of soft-story buildings.
Berkeley, on the other hand, has enacted legislation that requires the identification of soft-story buildings, notification of property owners and tenants, and an analysis of the structures. Many other California jurisdictions, most notably San Francisco, are working on developing their own ordinance to deal with this threat.
During the past year, Planning and Building Department staff researched how other jurisdictions were handling their own soft-story buildings. We wanted to find out what was working and what they would do differently. Our research led us to ordinances covering a range of solutions.
Locally, Fremont has passed an aggressive ordinance that will require soft-story buildings to be retrofitted within a strict timetable. Fremont was able to do this because the staff had previously identified the vulnerable buildings, notified the owners, and required evaluation of these buildings. Berkeley staff, on the other end of the spectrum, felt they still had a lot of work to do in identifying incentives, funding sources, and the extent of any required retrofit before they were ready to pass a mandatory retrofit standard.
In Alameda, we also have some work to do before we know exactly what the extent of our soft-story vulnerability is. Berkeley has determined it has 400 soft-story buildings containing nearly 5,000 units. Most of this type of construction can be found in apartment buildings built in the 1960s and 1970s.
In Alameda, the passage of Measure A effectively barred construction of soft-story residential buildings after 1973. The first step in our proposed ordinance is to spend the next 9 to 12 months identifying and cataloging our inventory of potentially hazardous soft-story residential buildings.
The proposed ordinance for Alameda is modeled after Berkeley's ordinance. If adopted by the City Council, Alameda's ordinance would establish clear soft-story retrofit standards through the adoption of Chapter A42006 of the International Existing Building Code. The work program established under the ordinance would allow the city to:
Identify buildings subject to the ordinance through research of permit records and site visits by Planning and Building staff.
Notify property owners that their building has been identified as a potentially hazardous soft-story building.
Establish a process to allow property owners an opportunity to appeal the potentially hazardous soft-story building determination.
Notify tenants and interested parties through the posting of a warning sign and the filing of a notice with the County Assessor.
Require the property owner to complete a structural assessment within two years of notification.
Require the tenants to allow inspections.
Establish a 15-year exemption from a new potentially hazardous designation once retrofit work is completed.
Once the soft-story buildings have been identified, the process of notifying the property owners and allowing for appeals should be completed within a 6 to 12 months. This extended period will allow staff to manage the influx of appeals and engineering reports. Engineering reports are to be submitted within 24 months of the date the owner is notified.
Based on the above timeline, city staff anticipates the project will be completed within four years.
Retrofitting structures subject to significant damage, up to and including collapse, is a win-win for everyone involved. Property owners will have buildings that, while damaged, will be repairable in less expensive and quicker ways than non-retrofitted buildings. Tenants will be able to live in buildings with peace of mind that their building is relatively safe. And Alameda will not be faced with numerous uninhabitable housing units and the need to find emergency shelter at a time when availability will be scarce.
The last thing anyone wants after a major disaster is to be remembered for what went wrong or what fell down. It is hoped that with the enactment of this proposed soft-story ordinance, Alameda will not only become a safer place to live, but we will avoid becoming the next set of indelible disaster images.
