Exterior enclosure composition tools

Architects and consultants who work with exterior wall design understand that the up-front carbon of the enclosure system often represents 15-20% of the building’s total embodied carbon. And, while the final wall design must respond to many criteria such as aesthetics, insulation, and control of moisture, the criteria of embodied carbon is difficult to gage in early design, as it often relies on life cycle assessments performed after the wall compositions have been established.

CECC has developed three early-design tools in EXCEL that can help to understand the embodied carbon of facades before modeling them and performing a life cycle assessment. In order to use the files linked in the following paragraph, you will need to unblock the files using the following steps:

1. Download the EXCEL file – it will go to your download folder (don’t open it yet).

2. Open your downloads folder.

3. Right click the file you downloaded.

4. Select Properties.

5. At the bottom of the Properties tab, select Unblock.

6. Select Apply and then OK.

7. The EXCEL file is ready to use.

One of the tools, WallCOMP© , allows the designer to choose the various layers in the wall composition, and gives results for total wall thickness, R-value, and embodied carbon for both the up-front stages (A1-A5) and the life-cycle stages (A-C). The second tool, WindowCOMP© , allows the designer to choose different window types and determine embodied carbon results similar to WallCOMP. The third tool, EnclosureSUM© , combines the results of the first two tools for a final result for each facade elevation.

These early design tools do not replace the need for life cycle assessments of the enclosure, but enable early-design decisions that can result in lower embodied carbon of the exterior enclosure.