I believe they are one and the same file. I can only speak to running ResStock using the buildstock_local command.

Depending on where you assigned the project_directory in the YML config file, when you run buildstock_local it will create a buildstock.csv file in the housing characteristics of that project_directory after the sampling has been executed as the first part of ResStock's measure workflow.

If you notice, that buildstock.csv file doesn't exist in the housing characteristics directory previously (when you download ResStock from github for example, it is not in the project_national housing characteristics folder.

See if you can use a smart comparison tool to verify they are the same, I'm thinking something like Atom's SplitDiff but for csv files.

I wouldn't be suprised if this behavior also exists when just executing sampling using buildstock_local --sampling_only