"Eric the Red" wrote in
:

I have recently moved to a house in a typical surburbain area. At the
end of the garden there are some conifer trees that must be over 30
foot in height. With the way that the sun moves throughout the day
they do not affect the light in my garden but one of my neighbours
gardens must be in constant shade. Nothing has been said by the
neighbour but I feel I should cut them down to a more reasonable 15 to
20 foot. I would like to keep some height as they obsure the view to a
rather ugly building behind the houses.

Assuming they are leylandii or similar, it's likely that they will grow
back again over time, and present the same problem in a few years. The side
branches will grow round and up, and make a new growing point.

It's also worth remembering that the height they are now is not necessarily
the potential maximum height. They may get a lot bigger.

I would have a chat with the neighbour first: he/she is much less likely to
be annoyed about whatever you decide to do if you talk it through
beforehand and explain your reasoning.

Personally (and depending on exactly what sort of tree they are) I think
I'd take them down now and replant with smaller trees. They may take a
while to get back to your perfect 20-foot height, but at least they will
never be *too* big.

Victoria