You can also explain it softer, instead of saying the bad things about this build you can also give him tips to improve it.Oh it looks awful. Looks like a cube , then you put two slopes on top . 0/10 .
Its like you've taken everything you shouldnt do and shoved it into one build
But you know what's worse ? The interior .
There is nothing inside . The while thing doesnt look like a house or shed it looks like a cuboid .That is not how to build. Go watch grian
Anyways like many others said above, it's a good build to start but i think it needs some improvement :)