While the Millennium Tower continues to sink as legal battles ensue over who's at fault and should pay to stabilize the structure, another tower on the same block recently became a shining example of earthquake resiliency.

The new building, 181 Fremont, recently achieved a REDi Gold Rating, based on the Resilience-based Earthquake Design Initiative developed by Arup, a design and engineering consultancy. According to the design and planning guidelines, the rating denotes that a structure will be able to withstand a 475-year seismic event, or magnitude 7.5 or magnitude 8.0 earthquake.

A rendering of 181 Fremont, where the green space beside it is the intended location of a subway line, and the sliver of tall glass building on the left is the Millennium Tower.

"Given 181 Fremont's location in a seismic zone, building height, and mixed-use nature, we felt strongly [it was worth] the expenditure of extra dollars to achieve a REDi Gold Rating, [which] resulted in a safer and higher-quality product. [The tower] will offer Class A commercial space and the highest-quality luxury condominiums on the market," Jake Albini, senior manager of real estate development at Jay Paul Co., which developed 181 Fremont, said in a statement.

To achieve this standard, Jay Paul Co. and Arup, which served as the structural and geotechnical engineer on the building, included viscous dampers within the steel megabraces that will act as shock absorbers and uplifted megacolumns to significantly reduce the potential for earthquake damage. These techniques also reduce wind vibrations, which alleviated the need for a mass roof damper and freed up the entire penthouse floor for salable square footage.

In addition to being designed to reduce earthquake damage to a structure, the REDi Gold Rating was developed to improve the performance of egress systems in cases of emergency and create contingency plans to reduce recovery times. Arup is currently devising a similar rating system for flooding.