Which tree to use?

We would like to create a view barrier. The view out the front window of the mountains and water to the south are blocked by the construction of a large 3 storey building about 3 blocks away. I would like something that is green all year and would grow no larger than 25' tall. Any suggestions

 

Thuja occidentalis 'Smaragd'. You will be waiting many years for it to grow tall, but then you won't see it shoot up over 25 ft. anytime soon either. That's how it works, for the most part - nice compact, short plants are slow and fast plants are tall and open.

 

Buxus varigated or Juniperus Hibernica,I have this in my garden is easy to prune for topary forms, if you want natural forms Buddleja Davidii or Cotonaster franchetii(red berry).

 

Good point made by Alex that shrubs might also work. How much height do you actually need?

 

Hi KarinL, I am looking at the barrier to be no higher than 25 feet

 

I was asking what the minimum is; you already gave the maximum!