This works on the assumption that the "size" field indicates the amount of space on the road that the building takes up. I could be wrong and it might be the "footprint" field that indicates this instead, in which case the "Space Efficiency" column would be incorrect. It would be great if someone could test this out.
Anyway here's the new rankings:
- Green House
- Nova Tower Block
- The Grid Building
Here's the spreadsheet again:
Comments welcome!

