Hi, first I’ll say it looks very good especially considering it’s your first architectural work. You had a bit of modelling challenge there to get those shapes and the image pops out nicely. The thingh I would change is the lighting that doesen’t look natural for a daylit exterior. I know you meant to match the cloudy diffuse light to the sky background but it is somehow too soft and looks more like artificial product lighting. Maybe the sky is not the best choice, you could test several an find one a bit less dramatic, I think the sky takes the eye away from the building, it should blend better. The other detail I’d critic is the camera angle, for this type of image a level camera looks more proffesional (camera and target on the same horizontal plane). Using 3 point perspective works with images like skyscrapers or dramatic building details.
Hope this made sense and thanks for sharing!