Hello Paul, If your Serviceberry is the same as the ones I am familiar with, these are considered large shrubs or a small tree and often multi-stemmed. The roots should not harm a foundation that is constructed properly and made of appropriate materials. Homes built using dry laid flagstone or similar stone material do not have the proper structural strengh to resist the side forces created by an expanding root, they do hold up a home just fine. Be sure to space the plant away from the sidewalk (and home) to allow for several years of growth before you need to start pruning. When you do prune, make every effort to retain the natural shape and enjoy the blooms!
Sincerely, Richard Hentschel
