Tuck-Under Parking and the Mandatory Los Angeles Soft Story Retrofit Program

Table of Contents

The Mandatory Los Angeles Soft Story Retrofit Program is designed to strengthen buildings with tuck-under parking that are vulnerable during earthquakes. Tuck-under parking is typically found in condo or wood frame buildings and requires special attention when engineers are retrofitting them for seismic safety. This blog will discuss the different methods used to retrofit tuck-under parking structures and explain why they are necessary for earthquake safety. 

What Is Tuck Under Parking?

Tuck-under parking is a type of parking structure commonly found in condos, apartments, or other wood frame buildings. It refers to a garage that is built underneath the living space of the building, creating an open space between the ground floor and garage level. This design was popularized because it allowed more living space while still providing on-site parking. The downside is that during an earthquake, these structures can be especially vulnerable to collapse due to their lack of structural support. 

Retrofitting Tuck-Under Parking Structures for Seismic Safety

When engineers are retrofitting tuck-under parking structures, there are two primary methods used: braced frames and moment-resisting steel frames. Braced frames are constructed using steel or concrete braces to reinforce weak points in the structure’s walls, columns, and beams. Moment resisting steel frames use a combination of steel members connected by welds or bolts to create a strong framework that can withstand seismic forces. Both methods provide additional structural support to increase the building’s resistance to earthquakes. 

Why Is The Soft Story Retrofit Program Necessary? 

The Mandatory Los Angeles Soft Story Retrofit Program was created in response to research conducted after the 1994 Northridge Earthquake which revealed that tuck-under parking structures had been particularly vulnerable during the quake. With this knowledge, the program was created as a way to strengthen existing buildings before an earthquake occurs and prevent unnecessary damage or injury due to collapsing structures. 

Benefits Of Retrofitting Soft Story Structures 

There are many benefits associated with retrofitting soft story structures for seismic safety: increased safety for occupants, improved property value due to greater stability, and reduced insurance costs due to decreased risk of damage from future earthquakes or other natural disasters. Additionally, retrofitted buildings may be able to withstand greater shaking forces than unretrofitted ones which could mean less overall damage if an earthquake strikes.  


Tuck-under parking structures require special attention when engineers are retrofitting them for seismic safety since they can be particularly vulnerable during earthquakes due to their lack of structural support. While there is no guarantee that any building will be completely safe during an earthquake, retrofitting them can significantly reduce their risk of collapse and provide greater protection for occupants should an earthquake occur in the future. The Mandatory Los Angeles Soft Story Retrofit Program provides owners with safe and cost effective solutions so they can ensure their buildings meet current seismic requirements while also increasing safety for occupants and reducing insurance costs over time.