Good question! Best practice is to always set all energy/water entries in the design as the ‘Default Grid’. This way, you can be sure that the design will always be consistent with whichever grid you’ve specified in the project level under ‘Site Attributes’. Also, if you ever clone the design for a different project in a different state/country, you only need to change the grids for the whole design in one place (Project Level > Site Attributes) rather than for every energy/water entry. Of course the option to do otherwise is there in the rare situation where you might actually need to change the grid to something else (i.e. non-grid sources).