Pretty much the same orientation and positioning my greenhouses are in, except right in front of mine is my neighbours 30 foot willow tree casting a shadow till about 11:30! On top of that we're in a valley and by about 4:30pm one greenhouse is then shaded by our house and the other around 6:30pm by the surrounding hills. I grow Pings (and Haworthias) in the one losing the sun earliest and VFTs, Sarrs, Darlingtonias, Droseras, Cacti etc etc in the other. My plants grow OK and I don't think you'll have a problem with this setup. You could always add growlights if you do find you need more light (assuming you put power in your greenhouse ). And don't forget the golden rule of greenhouses which is, the one you buy is never going to be big enough, so do buy the biggest you can afford. Good luck.