A few residents are worried about damage from tree roots to their foundations or drains. From my research on line and with horticulturally minded people I have found that the roots of most trees do grow longer than their branches, mature Sycamores roots can be 50 – 70ft long but at that length they are not ‘aggresssive’ roots. So you are safe from trees at the back of your house if the branches are not over hanging it.
Tree roots will not usually be able to damage drains or properly laid foundations but if there is already a hole in the drain they will pop straight in there and suck up the moisture, growing the full length of the drain if left to it!
It seems that only the trunk of a tree, and those roots directly coming out of the trunk, growing right next to a wall are strong enough to damage it, that is the problem we are having with Cherry Trees lifting the pavements in South Dublin.
I also learnt that in the south of England trees roots can absorb all the available moisture in summer making the earth shrink and possibly causing movement of building walls but (unfortunately?) we do not face that problem here as it is never dry enough!
More trouble is caused by the branches of a tree, but that would take up another whole website! This is the most thorough article I found online: