Ability to Modify default buildings in Modkit

[CulCol]

I tried to modify standard game - Medium factory - capacity, but the file "Buildings.dbf" from the ModKit (Data) sources is empty, there is no default buildings when open Buildings.dbf.
It would be nice to have the ability to modify all default game items (buildings, and other items); put sources from last version in Mod Kit Data folder.
For example how can I change medium factory to ocuppy 1x1 layout but not 2x2? And change its capacity?