Weighing the Financial and Sustainable Benefits of High Performance Structures in Seismically Active Regions

Author

Alia Talina Barajas, California Polytechnic State University, San Luis ObispoFollow

DOI: https://doi.org/10.15368/theses.2013.152
Available at: https://digitalcommons.calpoly.edu/theses/958

Date of Award

7-2013

Degree Name

MS in Architecture - Architectural Engineering

Department/Program

Architecture

Advisor

Jill Nelson

Abstract

This thesis investigated the potential advantages and disadvantages of high performance structures by comparing the financial and environmental impacts of a performance based four-story office building to one designed to meet minimum code-level requirements.

To generate a comparison, the lateral system of a four-story structure utilizing buckling restrained braced frames was designed to meet code-level requirements per the American Society of Civil Engineers’ Minimum Design Loads for Buildings and Other Structures (ASCE 7-05) and again to meet the immediate occupancy criteria defined by ASCE 41-06 Seismic Rehabilitation of Existing Buildings. The following was then performed:

• Test the structural performance of both buildings using simulated code-level and maximum considered earthquakes
• Develop construction costs of both structures using RSMeans Square Foot Cost and Construction Cost Data
• Determine the financial benefit associated with the upgraded structure by subjecting both structures to a suite of earthquakes
• Calculate the carbon footprint generated during each building’s construction.

The final project costs for the code level and immediate occupancy structures were $27.43 million and $27.93 million respectively, resulting in an upgrade cost of $500,000 or roughly 1.8% of the overall project cost. The upgrade cost was then input in FEMA’s Benefit-Cost Analysis, where it found the upgrade cost resulted in an annual savings ranging from $43,000 to $98,000 over the building’s 50-year life cycle.

The carbon footprints were generated using BuildingScope, which relies on volumetric quantities of construction materials. The final models resulted in a carbon footprint of 7890 CO₂ eq and 7940 CO₂ eq for the code level and immediate occupancy structures respectively, showing favor for the structure utilizing fewer materials.

Although the additional materials used in the immediate occupancy structure resulted in a slightly larger carbon footprint, the added capacity will decrease damages, resulting in an overall reduction of energy generated during the building’s life cycle.