Neighbours problem conifers

Hi, Im after a bit of advice from gardeners that know their stuff (as I dont really).

My neighbour has a wild overgrown front and back garden. He has 2 large conifers in his back garden that are approx 40 foot high and a what I think is a spruce/fir tree in his front garden that is also about 40 foot high. These trees are roughly 20 feet from my house. I am currently having a new conservatory built and numerous roots have had to be cut away from the foundations to dig footings.

What can i do to try and make the neighbour do something about these trees before the roots damage my drains or foundations?

Any advice would be greatly appreciated 

I don't have direct experience of this other than the usual cats and noise etc-this site offers some useful advice that might help

https://www.gov.uk/how-to-resolve-neighbour-disputes/overview

But neighbour disputes are a legal minefield and sometimes they may not be aware there is a problem-you may though have too seek professional advice sooner rather than later

The first thing to do is to try and discuss the problem in a friendly way with your neighbours. The roots are trespassing on your garden, so you are allowed to cut roots in your garden. But I'm not sure of the situation if there is a preservation order on the trees. The last resort is to go to court. There is a website called "garden law" which may help.  http://www.gardenlaw.co.uk/trees.htm 

The address above doesn't work because there should be an l after the last m. I'll try again, but you can google it. www.gardenlaw.co.uk/trees.html  that's better, I hope.