Comparing the environmental impact of structural systems

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This tool allows architects and engineers to explore the environmental impacts of the recycled content and cement replacement in structural materials. The calculator currently focuses on parking structures, but will be upgraded to include other types of structural systems. This tool uses material take-offs of existing parking structures with one-way spans: one pre-cast concrete, one post-tensioned concrete and one cellular steel. By selecting existing parking garages built over the last 10 years of similar height and in the same seismic zone, the design loads, column lengths and structural layouts are similar. Enter the recycled content or cement replacement of each structural element below and click on the "Compare" button to update the table of embodied energy and carbon values.


Griffin, C.T., Bynum, L., Green, A., Marandyuk, S., Namgung, J., & Burkhardt, A. (2013). Comparing the embodied energy of structural systems in parking garages. In Proceedings of the 2nd International Conference on Structures & Architecture (ICSA2013). Guimaraes, Portugal, 24-26 July 2013.

Note: These are initial embodied energy and carbon values (cradle-to-gate). Embodied energy and carbon values extrapolated from Inventory of Carbon and Energy v2.0 from University of Bath Sustainable Energy Research Team


Steel - Recycled Content
Structural - Beam, Column % 0% 100%
Decking % [37% average basic oxygen furnace, 90% average electric arc furnace] 0% 100%
Reinforcing Bar % [99% typical] 0% 100%
Wire/Tendons % [99% typical] 0% 100%

Concrete - Cement Replacement
Foundation % [8% average, 15-25% recommended, 50% maximum, 100% hypothetical] 0% 100%
Structural - Slab, Beam, Column % [8% average, 15-25% recommended, 100% hypothetical] 0% 100%
Precast % [8% average, 15-25% recommended, 60% maximum, 100% hypothetical] 0% 100%

Parking Garage Structures
System Type Embodied Energy (MJ/ft2) Embodied Carbon (lb CO2/ft2)
Cellular Steel 229 48
Precast Concrete 122 36
Post-tensioned Concrete 133 36


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