Cast in place concrete walls; one door to the outside (up stairs to a bulkhead, door is weather tight and no air gets through); two windows, wood framed, insulated glass.

Heat is hot water by propane. Furnace and storage tank sit in a small framed and drywalled room with a door in the basement corner. All hot water piping is wrapped with insulation.

Ceiling is open to joists and is insulated between the joists with fiberglass batts, paper facing the living spaces above.

Door at the top of the stairs to the living space is usually kept open about 3 inches to allow access for cats.

Now, here's the question.

Basement is cold. It never warms. Haven't put a thermometer down there yet, but it's not cold enough for water to freeze. It is colder than any other basement I've ever had or experienced.

Any ideas why? Is it simply the lack of a heating system down there? Is it the insulation between joists above?

I figure it shouldn't be naturally warm there, but it should be a little warmer than it is. Any suggestions you might have would be appreciated. If there's something I can do myself to attend to the issue, I will. I have some construction experience. Otherwise, we'll call in the pros....