Greenhouse floor isolation

Looking at building a lean-to greenhouse on the south face of my house.  House is brick so I'll get the solar gains in winter but also I'd assume some conductive loss as heat dissipates across the rest of the wall not inside the greenhouse. I'm more concerned about heat loss for the same reason from the large paver patio it will sit on. The greenhouse floor will not get as much direct sun. Should I go thru the arduous task of thermally isolating the greenhouse floor from the rest of the patio? This will be any entirely container and flats greenhouse.

Thanks!