By yard---you know this would seem basic, north south...but there is no requirement for zero impact in the code...there could be, "no net difference from a typical grassy field for heat, and shading typical of a forest. They could put in white roofs, tree or a combo...one of the reason it like the roofs is you can design for solar panels and then plug in your car! But trees are good, heat in the short term for carbon, cool your car so maybe you use less AC...but this takes leadership and it costs money.