3rd perspective drawing

This is the 3rd drawing I did in perspective class.  This is the first time we used shading and in order to see the overall tone we were instructed to put a value scale in the picture.  Technique wise I think I did an ok job on this.  Their are some mistakes, the corners don't stand out , their would be some differences in value in each corner, and some of the areas aren't dark enough.  Overall though I think this is a really solid piece.  The basic shape of the room is my living room and kitchen, I went with simpler furniture and rearranged it but the basic design came from my house.  We had to add people into this picture, which is another first but I like the father and son staring each other down across the house while the mom is in the kitchen trying to stay out of it.  This doesn't represent how my teenage years were and hopefully doesn't represent how it will be when my son becomes a teenager but it reminds me of the feeling of being a teenager in the 90's.  I like that now I am a lot closer to the dad in the picture and it's set in my current home but evokes the feelings of being a rebellious little punk, it has an odd mixture of seeing it from both sides.  This drawing probably took me the longest of any drawing or any project I have done so far, I spent upwards of 20 hrs working on it, but now looking back I loved every minute of doing it and I really like this piece, mistakes and all.