And indeed I've done a PS mask only for the roof, cause automatic color correction in PS give me nothing, no changes, when I tried it on the whole picture. But If I applied automatic color correction to the roof, it really push up the white. That's why I've now this bright roof, I was thinking that with a bright sun it would be fine...and maybe fit that cartoonish mood given by the grass...It's crazy how 5 minutes in post could completly change a picture you have work on during 2 days in 3D apps.
sancheuz, thank you! The lake of lower rail didn't disturb me when modelling...I'll take some more references pictures next time I think. For the trees yes, I completely agree, for now I focus mainly on the house render and I give a lot less time to the environment (nature in 3D is really sometimes a nightmare), another thing I have to learn for the next picture!
thank you BVI, the tiles are modeled and then put on roof with an automated tool (lwcad)