Our house is on a hill and we're higher up than our neighbours. There are conifers planted at the edge of our drive next to their house. They're around 10 feet tall and give us privacy. They want us to cut them down significantly. But in doing so not only do we have the cost of the work but we then end up with a view of their house. Am I being unreasonable in saying no. They are managed and we will not allow them to get much bigger than they are now. I've attached a drawing to show what I mean.