Hi,

I’m looking to get a rough ballpark for operating costs to renovate my basement. I thought I could just get away with a couple electric baseboards but my numbers must be wrong as it seems pretty expensive given the size of the space. 

Assumptions: 
1940s granite block foundation, Boston
7′ ceilings
110′ of walls, 50% above grade, R-15 closed cell
550sf of uninsulated slab
84sf of Harvey windows and 1 exterior door

Roughly 10,000 BTUs @ 9F

I have this costing $3k a year using electric baseboard set at 72F. Is that in the ballpark? I heat my 2000sf house with an old steam boiler for ~$2,000/year. 

Kevin