I chatted with our report developer briefly and she recommends SU05 which shows both the fields you want. She added that you might go one better by downloading a Setup Update Sheet for Buildings & Organizations. Then, you could easily find the empty columns in Excel, populate the Primary Use and Floor Area, and then import the sheet and therefore the values you wanted to change.
I should add that one of our staff, Adam Hegedus, did a fantastic job with this new edition of the Sample Report Viewer. This should make it easier to find reports that show the types of data you want if you're not sure where to begin. Feel free to give us feedback on that, too!
Thanks for your help!
You're welcome, Alex! You inspired me to write this knowledge base article with your question: Finding Reports, Fixing Data