Highlights from this Month's e-Newsletter
In this new video, APA's Karyn Beebe, PE, talks to developer Barbara Monroy and project engineer Amir Deihimi, who explain how the Santa Barbara Apartments were value-engineered to address excessive building material costs.
Located in Rialto, California, an area with high seismic loads, construction of the complex had stalled due to prohibitive framing and material expenses. Monroy's search for more cost-effective methods and materials led her to Deihimi of Core Structure, Inc.
A switch to I-joist compatible glulam, double-sided wood structural panel portal frames, and shear walls using force transfer around openings (FTAO) analysis got the project back in the black while addressing the seismic loads.
Adding up the savings realized through replacing steel shear walls with wood and using economical glulam beams, "I think the developer, Barbara Monroy, ended up getting her seventh building for free," says Deihimi.
"Having to redesign this project was a tough pill to swallow when you've already paid for it once. But in analyzing and calculating all the numbers, it was well worth it," said Monroy.
Watch the video by clicking the link above, or read more in "Project Spotlight: Santa Barbara Apartments" below.
Santa Barbara Apartments
Although demand for housing in the area was rising rapidly, development of this new apartment complex in Rialto, California, had stalled. Estimates for the complex's framing costs were coming in on the high side, and the project just wasn't penciling out. So the developer had the complex re-engineered, and a switch to glulam and wood-framed shear walls got the project back in the black.
The 120-unit, seven-building Santa Barbara Apartment complex "is literally on top of a southern California fault line, so the seismic loads are significant," said Amir Deihimi, PE, of Core Structure, Inc. "But there are more affordable engineering solutions, and they had not been fully explored."
Deihimi replaced expensive steel framing with I-joist compatible glulam and double-sided wood structural panel portal frames using force transfer around openings (FTAO), a method of shear wall analysis popular in California, a measure that cut costs drastically without cutting seismic performance. "The end result is still a quality project, but the owner saves money, which allows them to invest in aesthetic features that make the project more attractive to their end user," said George Mears of Precision Framing Systems, Inc., framers for the complex.
Core initially focused the value engineering process on the prefabricated steel shear walls. Each apartment has its own garage and in the original design, each garage had four steel shear walls (two back to back). To replace the expensive steel walls, Core designed a cost-effective double-sided wood structural panel portal frame with force transfer around openings shear wall analysis. Core used the same method around the entire exterior of the building at all window openings. "The only thing we needed to add was the sheathing above and below the header," Deihimi said. "And if we're not doing that for shear, the framer has to fur it out anyway. Plus, the straps help us eliminate two hold-downs next to the opening. Often, those are HD-type hold-downs, which can be costly and difficult to install. But by using FTAO, we just ended up with a strap on each far end of the wall for this particular design."
Next, Core turned to the beams, which had been originally designed with parallel strand lumber (PSL). "From past experience, I have learned that using glulam beams will save 20 to 30 percent over costs of other engineered wood products," Deihimi said. "While PSL is slightly stronger, we don't always need the extra capacity; 99 percent of the time it's a direct size swap, and size for size, glulam is less expensive. Plus, framers tell me they like working with glulam beams because they are easy to install."
To learn more about the project, download Case Study: Santa Barbara Apartments, Form S125. Printed copies of the case study are also available for $1 each.
Glued Laminated Beam Design Tables
Glued laminated beams (glulams) are used in a wide range of applications in both commercial and residential construction. These design tables provide recommended preliminary design loads for two of the most common glulam beam applications: roofs and floors. The tables include values for section properties and capacities and allowable loads for simple span and cantilevered beams.
Download Glued Laminated Beam Design Tables, Form S475.
Outside the Circle