My track layout is going to be tight in some areas to I was wondering can you use z scale houses with n scale
That is illegal in 38 states at present. Where do you live?
No, I'm kidding. You can use whatever you like, after all it's your railroad. The question is, will you be content with the realism and how it looks?
If my math memory serves me, Z-scale is roughly 73% the size of N-scale. So any structures you use in your example would be about 25% smaller than what they would be in scale. For example, let's say you had a two story building, roughly 28' tall in real life. In N-scale, that would be approximately 2" high. In Z-scale, that would be about 1.5" high, i.e. half an inch shorter. That's not a huge difference to the eye, but it is a moderate difference in scale. To some, that's no big deal; to nit-pickers, that's enough to cause a stroke. Do what makes you happy.
My suggestion would be to try and find a couple pre-built Z-scale buildings and compare them to your trains, to see whether you're satisfied. I suspect if you have buildings away from the tracks or in the distance, it might work. But a Z-scale station right next to your train? Might look funny.