Rook, IMHO they are not new houses with sod, anymore than the trim building, with its green grass, was sodded.
It's currently around 1 to 4 deg C. in Windsor, and because of conditions last week, no doubt it was below freezing. It's been 29 to 32 here most of last week, and down to the mid-teens at night. No green grass here, yet, and we are in the middle of mud season.