Artificial flooring is now required for most factory buildings, and for more advanced buildings a more sturdy foundation is required to build on.
- The advanced machines in space age require refined concrete or its hazard variants
- Advanced base game machines such as roboports, nuclear power buildings, and beacons require some form of concrete
- most other production buildings and turrets require at least stone brick flooring

With space age enabled, all buildings can still be placed on space platforms, and to help with starting on new planets the rocket capacities of concrete and hazard concrete have been increase to 1000 and 500 respectively.
Directly upgradeable buildings such as the Assembling Machine 3 and Steel Furnace do not require upgraded flooring (simply because the modding API doesn't allow it)

Compatibility with modded buildings is not included, though they should be allowed to be placed as normal instead of being disallowed from placing anywhere.