Is it harmful to drill holes into the foundation of an older home in order to finish the basement?
My Home is over 120 years old. It is brick and the floor is concrete. We would also like to insulate if possible. We have already had the basement waterproofed.
I like older homes! Sounds like yours might have some historic value.
Please check with a licensed General Contractor before doing anything for safety and liability reasons if you have insurance. Some floors have a drainage weeping system for leakage. Drilling holes might disturb or cause damage.
Without seeing or knowing more about what type of holes you are drilling I would check with a GC.