We own a small city lot in Ladysmith BC that has a rather large (35') tall arbutus tree on it. The developer 5 years ago put a road thru that severed a lot of its roots on the north side and then he put in a retaining wall which is within 2 meters of the tree trunk. The tree since that development has looked sickly according to the people that live there and we see very few leaves growing on the remaining tree branches. To this point the tree has benefitted from the lot being open and any water from rain would course across and supply some moisture to the remaining roots. We will be building on the lot on the south side of the tree within 4 meters of the trunk ( small lot) and feel we might do irreparable damage to the remaining root system. Not only that but we will be addressing water drainage across the lot by rooting any ground water away from the house, and certainly the tree. We will also be creating a shadow that the tree will have to live within quite a bit of the time. Could you advise what root system this 35' tree would normally have? Secondly, given the situation is it worth trying to save the tree or is it safer given the size of the tree to remove it now before it completely dies and falls on the house? Any suggestions would be greatly appreciated.