Available at: http://digitalcommons.calpoly.edu/theses/958
Date of Award
MS in Architecture - Architectural Engineering
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.