The ATHENA® EcoCalculator for Residential Assemblies provides instant LCA results for common building assemblies based on detailed assessments previously conducted using the ATHENA® Impact Estimator for Buildings.

Please note that the current version of the EcoCalculator for Residential Assemblies is v1.1

As data for other building assemblies becomes available, those assemblies will be added to the EcoCalculator for Residential Assemblies.

To freely download and use the EcoCalculator for Residential Assemblies, you will need to pick the most appropriate climatic region for your building. This choice affects the specific assembly definitions.

Although the EcoCalculator for Residential Assemblies is presented in an easy-to-use Excel spreadsheet format, you may find it useful to review or download the User’s Guide . Detailed assembly definitions, assumptions and related information are provided in a separate Definitions and Assumptions document that can also be downloaded in a pdf format.

Please note that the EcoCalculator for Residential Assemblies was developed for and is supported only on Microsoft Excel. Any other spreadsheet software that is reportedly Excel compatible is not supported. The OpenOffice CALC spreadsheet opens EcoCalculator files, but we have not verified the results on that application. Apple’s Numbers application cannot open EcoCalculator files because they are password protected: they have formatting and content that needs to remain locked in order to ensure results are reliable. The EcoCalculator Excel files contain NO MACROS.

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EcoCalculator for Residential Assemblies Release Notes

Version 1.1

January 2011 : Version 1.1 has been released to reflect the updates and enhancements to its parent software, the Impact Estimator(version 4.1.13), details of which can be found here.

Version 4.1.12 of Impact Estimator introduced a change in the energy consumption summary measure, from "Primary Energy Consumption" to "Fossil Fuel Consumption", and as such, EcoCalculator for residential assemblies now presents the "Fossil Fuel Consumption" summary measure.

Two bugs have also been corrected:

• In both the "Foundations & Footings" page and "Columns & Beams" page, the total square footages were not being added correctly and have been fixed. This error did not affect the LCA results in the Summary page, it only affected the column totals (and therefore the percentage contribution of each individual assembly) on the assembly pages themselves.

Version 1.0

November 2010 : A Residential version of the EcoCalculator was developed to allow assessment of single family residential buildings, whether detached, semi–detached, or row houses. Version 1.0 is the initial release.

All assemblies were assumed to be used in single family residences with a 60–year life span. Assembly structures were modeled on a building with a 30’ x 30’ footprint, or 900 square feet. A 20% window to wall ratio was assumed.

The biggest difference between the Commercial and Residential versions is the number of choices with regard to roof and floor structures. In general there are fewer choices in the Residential version, reflecting the realities of constructing single family residences. However, asphalt shingles are an area where there is more choice; in the Commercial version there is one type of asphalt shingles, while in the Residential version there are four to choose from. The regional options, assembly categories, environmental performance measures and generation of results are the same.