When a building sits in a seismic zone, one question needs to come up early in planning, especially on renovation and change-of-use work: Is the structure ductile?

Building Design + Construction highlights that reinforced concrete can carry gravity loads and still perform badly in an earthquake if it lacks ductility, or the ability to deform without losing strength. Early reinforced concrete buildings were built before ductility expectations showed up in modern codes. Today, the industry recognizes that details like properly placed and tied steel reinforcing at critical locations, including beam-to-column joints, play an outsize role in how a building behaves when the ground moves.

FEMA points to the International Building Code and International Existing Building Code as key reference points for seismic provisions, while also noting that adoption and best practices for concrete and masonry seismic retrofits vary widely. Some jurisdictions have moved toward stronger requirements for concrete and masonry buildings, including screening and retrofit ordinances.

San Francisco provides a clear example. Owners of certain early- and mid-20th-century concrete buildings are receiving notices tied to a mandatory Concrete Building Screening Program. The intent is to build an inventory of buildings viewed as hazardous during an earthquake, particularly those categorized as non-ductile. The article also notes that other cities have introduced screening for unreinforced masonry, including brick buildings, and for concrete buildings, or both. Seattle and Portland, Oregon, have targeted brick and unreinforced masonry structures, while Los Angeles and Long Beach have enforced mandatory ordinances addressing non-ductile concrete buildings and other vulnerable types.

For mason contractors and retrofit teams, the practical starting point is documentation. Gather structural drawings, prior retrofit records, and past seismic evaluations. When information is missing, site observations help confirm the structural system and whether a property falls under local screening rules. From there, owners and project teams can map the regulatory path, develop conceptual strengthening approaches with a structural engineer, and then bring in contractors early to evaluate constructability, cost, phasing, and schedule impacts. The article emphasizes planning early, before deadlines and project schedules take control of the decision-making.

Read the full, original article from Building Design + Construction here.