Earthquake Risk to Historical Buildings

Seattle, with its rich history and diverse architecture, is home to over 1,100 historic buildings that were constructed before modern building codes were introduced in the 1950s. However, these historic buildings are now at risk of earthquake damage, according to a recent report by the Seattle Department of Construction and Inspections (SDCI).

The report, which was released in January, identifies more than 1,100 masonry buildings in Seattle that are at risk of damage if an earthquake were to strike the city. Of these buildings, 647 have no seismic retrofitting at all, making them the most vulnerable to collapse or substantial damage in the event of a major earthquake. The report notes that these problematic buildings are scattered throughout Seattle, with Pioneer Square and Capitol Hill having the most earthquake-prone buildings.

Amanda Hertzfeld, a representative from the SDCI, said that each masonry building was built before modern building codes were established and some of these buildings date back to the 1800s. She also mentioned that they are currently consulting with building experts to pass an ordinance in 2024 that would require retrofits to unreinforced masonry buildings (URM).

The SDCI updated the list of confirmed URMs within the city limits in January, including a searchable online database. Building inspectors are concerned about how mandated retrofits would financially impact low-income building owners. To address this concern, a new city ordinance would allow building owners up to 13 years to complete retrofits to their structures.

According to the report, the SDCI would need approval from the Seattle City Council to require seismic improvements. In the process, plans are still being developed on how the seismic requirements would be mandated. As a result, officials said the Seattle City Council wouldn't vote on the issue until 2024.

The cost to retrofit all of Seattle's URMs is estimated to be $1.2 billion, as per a 2019 report. The report also shows that 478 URMs in Seattle city limits have 100 or more occupants.

Seattle's historic buildings are an essential part of the city's cultural and architectural heritage. However, the risk of earthquake damage highlights the importance of ensuring the safety of these buildings for their occupants and preserving the city's history. The SDCI's plan to require seismic improvements to these buildings is a positive step towards mitigating this risk and protecting Seattle's valuable historic structures.

Are Single-family-homes at Risk?

In addition to historic buildings, residential homes in Seattle are also at risk of collapse and damage during a major earthquake, particularly those built before the 1970s. These homes are typically constructed with unreinforced masonry or have inadequate foundations, making them more vulnerable to seismic activity.

Homeowners should prepare for earthquakes by retrofitting their homes. Earthquake retrofitting involves reinforcing a building's foundation and walls to withstand the lateral forces generated by an earthquake. This may include adding achors, shear walls, and foundation bolting.

In addition to retrofitting, homeowners should also have an emergency plan in place and be prepared with earthquake kits that include food, water, and other essential supplies. It is also important to have a designated safe area within the home or a meeting place outside where family members can gather in the event of an earthquake.

It is crucial for homeowners to take earthquake preparation seriously, as seismic activity can cause significant damage and loss of life. With the increased risk of earthquakes in Seattle, it is essential for homeowners to take action to protect their homes and loved ones.