The Export Building Information command is used to export the building envelope area in a tab-delimited text file. This report lists the total areas of roofs, walls, doors, and glass broken down by type and by facing.
To export the building information, go to
Ribbon: DM HVAC->Load Calculations-> 
->Export Building Information
Pulldown Menu: DM HVAC->Building Definition->Reports->Export Building Information
The information will be exported to a file named dm_bldg-areas.txt in your project folder. This file can be opened using a spreadsheet program such as Microsoft Excel.
Running the command again will overwrite the file. If you need to save any changes to the file, save it under a new filename. Otherwise, the changes will be lost if you run the command again.