The landlord's question is not easy to answer, and the feng shui in the old hutong is not necessarily bad. What's more, what you expressed will make me misunderstand, in the old hutong? Does the hutong pass under the house? That will be very suffocating. If you build it on one side, it is not good to have old houses on both sides of the new house.
This is just a discussion of what you wrote, not an absolute concept. For reference only.