How much does it cost to dig a basement in Boston (Somerville)?

[Adam Sankowski]

I just found out that due to the new Somerville zoning I can build an addition onto my two family in Somerville!

This would be about 600 sq feet. The next thing I’m trying to wrap my head around is do we dig out a new basement and try to make it liveable? Or just go for a slab? I don’t know if a slab foundation is allowed in Somerville just cause every house has a basement... And would you connect the new one to the existing one?

Anyways my question is how much would a basement/ foundation, for what is essentially a new build cost, so that I can figure out if it’s worth it? 600 square feet  here...

I know the first response is “well, it depends...” I know it does but just do your best to give me a ballpark for the Boston area. Or even just your area wherever that is? I can’t find even a slight idea online. How much is it just for the foundation and then to finish and make liveable would probably be like at least 60k with HVAC and everything right? 

Thanks so much for any advice/ info/ or direction here :)