Cost to update a brownstone in Boston

[Alan M.]

Does anyone have a sense of what it cost to update (not gut) a multi-family that's based in a brownstone in downtown Boston?

3 units, about 2,000 square feet each. 3 beds, 1.5 bath...potential to make it 4 beds and 2.5 baths as part of the update. Basement is 2,000 square feet and unfinished as well.