Genny,

Many thanks for your reply! I was not aware that my model was so "shitty" :-( I haven't realized it but I will go over the model with your images and try to understand why this happened trying to correct all the issues you have complained about.

Is there a tool or trick that you can maybe reveal how to see these issues at the end of the modeling process?

Genny, I know, what I asked for in my first mail takes a lot of time! It would be much appreciated if you can provide a tut video, but if this takes to much time, I would understand if you would say: hey guy stop, I have no time for that! No problem for me.
BTW Genny, the texture could be also a projection of a picture taken from a house like in many textures databases. I agree, a real texture looks much better...

Bullet: that's true that all material I used are lamberts. If you remember my first mail, I wrote that the game engine accept only textures made with lambert or phong.

Many thanks to you both for the answer.

Rg, Lecra