Green Roofs and their Carbon Footprint

Caitlyn Blaine Christian,; Christina McCoy; Blake Mitchell

Download Paper | Permalink

Conference: 2024 ASEE Annual Conference & Exposition
Location: Portland, Oregon
Publication Date: June 23, 2024
Start Date: June 23, 2024
End Date: July 12, 2024
Conference Session: Architectural Engineering Division (ARCHE) Technical Session 2
Tagged Division: Architectural Engineering Division (ARCHE)
Permanent URL: https://peer.asee.org/47514

Request a correction

Paper Authors

biography

Caitlyn Blaine Christian, EIT Oklahoma State University

visit author page

Caitlyn Christian, EIT is a recent graduate from the Architectural Engineering program at Oklahoma State University. She graduated with honors and with a graduate certificate in Integrative Design of Building Envelopes. She is currently working as a structural engineer at Thornton Tomasetti in Kansas City, MO. Her work focuses on steel connection design, complex geometrical structures, and construction engineering.

visit author page

biography

Christina McCoy Oklahoma State University orcid.org/0000-0002-5559-9853

visit author page

Christina McCoy, SE, RA teaches Architectural Engineering at Oklahoma State University. She is both a licensed structural engineer and architect.  She graduated from Oklahoma State with Bachelor's degrees in Architectural Engineering and Architecture.  She received a MS in Architecture from University of Cincinnati, focusing in the history and theory of tectonics in architecture.  Professor McCoy received a MCEng with a Structural emphasis from University of Kansas.  Her professional experience at Thornton Tomasetti gave her experience in long span structures, high rises, and steel connection design. Professor McCoy's interests lie in the intersection of structures and architecture.  Of particular interest are instances where building technology leads the cutting edge of design. 

visit author page

author page

Blake Mitchell Oklahoma State University

Download Paper | Permalink

Abstract

Green roofs have become an increasingly popular solution to neutralize a building’s carbon emissions, by mitigating thermal heat loss and gain, in addition to adding to the biodiversity of urban areas. However, designers should consider the additional structural measures needed to support the added weight of soil and vegetation and how this increase in structural material will affect the building’s overall carbon footprint. This case study uses a typical steel framed structure to analyze the positive impacts green roofs have on the operational energy usage and to compare the embodied carbon footprint of the building once the additional structural material is considered. To complete this analysis, the project uses a baseline building design: a commercial building located in Oklahoma. The structural design criteria were determined using typical dead and live roof loading, which was obtained from the ASCE 7-16, and the structural framing needed to support this loading. From the baseline data, a load determination and resulting structural design was performed for four different intensities of green roofs. Steel design followed the American Institute of Steel Construction 15th Edition Manual. The structural system, including beams, girders, and columns, were increased in size to accommodate the different loading conditions. An environmental analysis was performed alongside these iterations, with the goal of accounting for increased environmental performance due to the green roofs while also taking into consideration the carbon footprint associated with an increase in structural material. Tools used in this analysis include Revit for documentation, RISA 3D to perform structural design, eQuest to evaluate the operational energy, and Tally to account for the carbon footprint of each system. Once the environmental analysis and life cycle assessment was performed for each green roof type, this allowed for a comparison between the increased embodied carbon and the improved energy efficiency of the building due to the impacts of green roofs. The paper includes a precedent analysis that surveys the implementation of green roofs, along with an overview of how green roofs provide energy savings. Findings indicate that even though green roofs increase the need for structural material and increase the overall embodied carbon at the beginning of a building’s life, the aid that green roofs provide in the reduction of thermal heat loss or gain over the lifetime of the building is more beneficial.

Citation
Format

Christian,, C. B., & McCoy, C., & Mitchell, B. (2024, June), Green Roofs and their Carbon Footprint Paper presented at 2024 ASEE Annual Conference & Exposition, Portland, Oregon. https://peer.asee.org/47514

TY  - CPAPER
AB  - Green roofs have become an increasingly popular solution to neutralize a building’s carbon emissions, by mitigating thermal heat loss and gain, in addition to adding to the biodiversity of urban areas. However, designers should consider the additional structural measures needed to support the added weight of soil and vegetation and how this increase in structural material will affect the building’s overall carbon footprint. This case study uses a typical steel framed structure to analyze the positive impacts green roofs have on the operational energy usage and to compare the embodied carbon footprint of the building once the additional structural material is considered. 
To complete this analysis, the project uses a baseline building design: a commercial building located in Oklahoma. The structural design criteria were determined using typical dead and live roof loading, which was obtained from the ASCE 7-16, and the structural framing needed to support this loading. From the baseline data, a load determination and resulting structural design was performed for four different intensities of green roofs. Steel design followed the American Institute of Steel Construction 15th Edition Manual. The structural system, including beams, girders, and columns, were increased in size to accommodate the different loading conditions. An environmental analysis was performed alongside these iterations, with the goal of accounting for increased environmental performance due to the green roofs while also taking into consideration the carbon footprint associated with an increase in structural material. Tools used in this analysis include Revit for documentation, RISA 3D to perform structural design, eQuest to evaluate the operational energy, and Tally to account for the carbon footprint of each system. Once the environmental analysis and life cycle assessment was performed for each green roof type, this allowed for a comparison between the increased embodied carbon and the improved energy efficiency of the building due to the impacts of green roofs. The paper includes a precedent analysis that surveys the implementation of green roofs, along with an overview of how green roofs provide energy savings. Findings indicate that even though green roofs increase the need for structural material and increase the overall embodied carbon at the beginning of a building’s life, the aid that green roofs provide in the reduction of thermal heat loss or gain over the lifetime of the building is more beneficial.
AU  - Caitlyn Blaine Christian, EIT
AU  - Christina McCoy
AU  - Blake Mitchell
CY  - Portland, Oregon
DA  - 2024/06/23
PB  - ASEE Conferences
TI  - Green Roofs and their Carbon Footprint
UR  - https://peer.asee.org/47514
ER  -