Insulation in Old Home

[Brian Oney]

High Level Question: At what point would you spend money to add insulation to the attic of an old home rental (and hopefully leading to lower heating costs for tenants/not requiring them to buy a room heating unit)?

Details:

We bought the house as our primary residence 2 years before we were both laid off, so needless to say we didn't get a lot accomplished on it before we had to move for a new job. The house was built in 1910, wood frame and I just re-checked the attic on our way through (we live out of state) yesterday - it has about 2-3 inches of old blown insulation.

We of course didn't buy this as an investment property, so we are only $150 over the mortgage, insurance and taxes on a monthly basis. So we aren't swimming in money, ha.

I figure that the attic is #1 priority for insulation and I know our natural gas heating bills ran what seemed to be high while we lived there. Should we spend the $500-700 to add insulation to the recommended level? As a side note, we need to repaint in the spring as the paint on the wood siding is in rough shape (roughly $4000-4500 in all).