Hello, I've looked through the BC Landscape standards for what may be considered a large tree and for guidelines as to how far from a building's foundations one should plant large trees. The American Conifer Society describes a large tree as growing more than 25 feet over 10 years - somewhat helpful but is it not so that some trees grow quickly up to 25 feet or so and then broaden outward over time? On a side note, perhaps these are classified as 'large' along with other trees that reach 50 ft or more at maturity because their root structure is comparable? Does anyone know of an official standard for planting large trees near buildings and what is 'large' for that standard? Ideally the standard may also provide guidance for groups of large trees, for example, "avoid planting Weeping Willows within 50 feet of homes; Austrian Black Pines can be planted up to 20 feet" or whatever? I'd expect the source to use Latin names to sidestep misunderstanding. Is there a website or standards manual available to the public? I hope one of you in this grand community may know the answer! Thank you in advance.