Hi Kathleen, Kimberly here from landscape-solutions-for-you. Thank you for asking the question on apple trees close to a foundation.
The rule of thumb is most fruit trees won't damage a foundation. What type of apple trees do you have? Any tree planted up against a foundation is not a good idea. The tree won't grow naturally in height and width. How far away from the foundation is the trees?
I usually recommend to only plant small trees near a foundation and at least three to four feet away from foundation.
Make sure you properly water the trees with a full soaking instead of just surface watering. You can prune your apple trees to keep them in tack.
A lot of hard wood trees and other varieties aren't recommended along a foundation, but your apple trees should do no damage to your foundation if kept watered properly and pruned. I hope this helps some, and best of luck to with your trees.
Thanks again for asking the question here at landscape solutions for you. If you have any other questions feel free to ask. If you are still unsure about your apple trees, let us know, and we will continue to share some thoughts with you. Have a great day!
Kimberly