A first for Sacramento

When construction on downtown Sacramento's new $47 million Plaza Lofts on J Street began, it was an event that was long in the making.  The lofts were being erected on a lot that had been vacant for 15 years.  It was also the first apartment building in Sacramento to use a precast concrete hybrid moment frame system for seismic stability.  This system is more commonly seen in large-scale commercial buildings.  

The frame system manufactured by Clark Pacific, has been demonstrated through testing to have superior performance to a conventional cast-in-place concrete frame.  The building is able to handle large drifts while experiencing minimal damage because the 8-year-old system was designed with a post-tension, self-righting mechanism. The system's pre-stress design has enough pre-compression to maintain an upright position after the ground stops shaking from a major seismic event.   The Plaza Lofts is only the second residential building to use the system in the state and the first in Sacramento. 

Along with its seismic durability, the hybrid moment frame helped to save costs and speed completion.  Because the precast system was so flexible, the designers of the building were able to incorporate the columns and the beams as part of the exterior finish as well as the structure, doing away with the need to put money on exterior finish or paint, saving money during construction and over time in maintenance costs.  On average, total precast concrete can also save an estimated 5 percent to 10 percent in construction costs. 

As an added benefit, because total precast buildings can go up 25 percent to 40 percent faster than the standard buildings, the structure has been able to generate revenue sooner. 

Precast as a design tool

For this particular project, the precast system allowed for large amounts of glass to be used on all residential units. Each apartment has floor-to-ceiling windows that brings in natural light, air and views of downtown. Many units have up to 30 ft. of glass in the main living areas. The precast beams and columns feature various levels of sandblasting and reveals, creating a pattern that coincides with the pattern of the glass.

Clark Pacific worked with a local glass company, who supplied and installed the windows,incorporating accents of translucent and tinted glass set among both fixed and operable units, creating a Mondrian-like pattern on the entire facade.  The windows also keep the facades of the building from becoming monotonous and out of scale with the surrounding buildings.  The end results were the creation of very unique apartments with generous amounts of natural light, air and views.

Clark Pacific was able to create a surface on the precast concrete through sandblasting to create different levels textures, patterns and colors. 

Revitalizing downtown

Total precast can bring nicer, more attractive buildings to cities, including Sacramento, anchoring and helping to reshape the face of the community.  The eight-story mixed-use project is one of a new wave of long-awaited residential and retail high-rises aimed at reinvigorating Downtown Sacramento hoping to attract a cross-section of the community, including young professionals and state and government officials who might need temporary residence.  The use of precas concrete has helped to set 800 J Street apart from all other residential buildings that have been built in Sacramento.