Newly Finished Basement Not Heating Properly
Last fall, we had our basement finished by a small, local general contractor who came recommended by a friend. The job added about 700 sq ft of finished space to our previously 2000 sq ft home, which is heated by an electric heat pump, and has no separate heating zones.
The contractor added 4 additional registers to heat the basement, but the result was terrible. All throughout the winter the basement remained uncomfortably cold. So much so, that our children were unable to play there. The themostat is on the first floor, and when we turned up the heat, it became uncomfortably hot (!) on the upper two floors of the house, and still made the basement only just bearable.
To experiment, I spent a month closing the registers on the upper two floors (to keep them cooler and force more of the heat into the basement) -- this worked a bit, but still did not create a comfortable balance between the basement and the rest of the house -- and our electric bill absolutely sky-rocketed when I attempted this solution! (Was this an unwise way to attempt to fix the problem?)
I talked to the contractor about it this week, and he was quite friendly, but I feel as if he avoided addressing the issue directly or taking responsibility for the problem. Before I speak to him again, I'm hoping to be a bit more informed.
My question is this: Do you have guesses about what the problem might be -- or where someone would start investigating? What might be going wrong? If I push a bit, I want to be confident that he's considering the right things, and not avoiding issues that might have been poor decisions on his part.
(Our house is only 4 years old and therefore has windows and doors that are energy efficient. The basement is exposed on the back wall and has two large bays of windows and a set of french doors. The contractor used R-19 insulation on the exposed wall and I believe no insulation on the three poured walls. If I understand him correctly, he claims that poured concrete walls are very thick, and also have a layer of insulation buried on the outside, and therefore do not require interior insulation.)
Thank you so much for any ideas you can generate!
Your time is much appreciated!