For the latest information, resources, and guidelines related to COVID-19, please visit the

For DES operating procedures, visit the DES COVID-19 Information page.



What is an ELCCA?

Energy life-cycle cost analysis (ELCCA) is a decision-making tool for building owners and designers.  It provides a means of comparing the present values of two or more design alternatives.  A computer model is developed early in the design process using energy modeling software for the basic building design.  Various changes are made to the model that reflects design alternatives.  The model calculates the energy costs for each alternative.  For each alternative, first costs and maintenance costs are calculated, and along with the energy costs, are input to the ELCCA spreadsheet.  As alternatives are adopted, the model is refined.  A cost-effective design may consist of many decisions based on this process.  The report documents the process, what was studied, and the results.  The addendum addresses review comments and includes a description of the recommended building.

The 2005 version of the guidelines introduces and integrates the process known as Leadership in Energy and Environmental Design for New Construction (LEED-NC), a registered trademark of the United States Green Building Council (USGBC).  This approach to new construction design is mandated for state buildings by RCW 39.35 D.  The guidelines seek to have public buildings consider the attainment of a high level of energy performance, requiring the analysis of a design that attains at least four LEED points in the Optimize Energy Performance category.