The objective of this project was to demonstrate how to incorporate environmental costs and benefits into traditional life-cycle cost analyses (LCCAs) and total ownership cost (TOC) analyses for military construction projects using two key metrics: life-cycle greenhouse gas (GHG) emissions and the net present value (NPV) of life-cycle costs with monetized GHG emissions. The focus was buildings constructed before World War II (Pre-War Buildings).
As part of the specification of each project alternative, the team applied the following key design criteria:
The team used RSMeans CostWorks as the primary source for cost data but also reviewed project cost records for recently completed projects at each installation and interviewed local contractors that have had experience at the installation or surrounding market. Demolition and typical environmental remediation (lead paint and asbestos) costs were included in the cost estimates for the project alternatives.
The buildings selected for this demonstration have experienced modifications, damage, foundation movement, aging, and exposure to moisture. The team’s evaluation was based on an approach intended to consider the original structural design, the condition of materials, the effects of age and past usage, hurricane and other damage, and the requirements for continued service. The team made on-site observations to visually assess the condition of the structures, identify the structural system types, and obtain field measurements of primary structural elements.
Energy Consumption Estimates
After initial construction or modernization, GHG emissions are generated by energy consumed during ongoing building operations, including lighting, heating, and cooling. To estimate these emissions, the team’s mechanical engineering consultant determined the thermal insulation values (known as R- and U- values) of the door, window, roofing, sheathing, and exterior wall materials specified in each Project Alternative based on industry standards and professional judgment. These values were then input into Trane’s Trace 700 Building Energy and Economic Analysis Software Version 6.2 using the TETD-TA13 methodology for cooling load and the U-factor by area by temperature difference and instantaneous room load calculation method for heating load.
GHG Emissions and Calculation Tools
Scope 1 emissions refer to emissions generated by use of energy at the building or building site, such as natural gas for a boiler. Scope 2 emissions are for purchased energy not controlled at the site, such as electricity from a utility company. Scope 3 emissions are related to the production and transport of building materials as well as transportation of waste and demolition debris to an offsite disposal site. As of the date of this demonstration, there is not a single, widely accepted, publicly available GHG calculator that can provide estimates of Scope 1, 2, and 3 GHG emissions. To estimate GHG emissions, the team reviewed off-the-shelf calculation tools and ultimately utilized the following:
The team used the EPA analysis of the American Power Act as the source of per CO2e ton pricing data.
Life-Cycle Cost Analysis
To prepare the LCCA, the team adopted the standards set forth in the U.S. Army Corps of Engineers’ Manual for Preparation of Economic Analysis for Military Construction. Key assumptions included: (1) 30-year study period, excluding project lead time; (2) current dollar analysis, all in 2012 dollars (e.g., no CPI escalations); (3) Real 30-year discount rate from OMB Circular 94-A, Appendix C.
Based on the data from the LCCA analyses, overall findings included:
Based on the findings and observations of the project team, the following recommendations were offered to the Department of Defense (DoD) for consideration: