If you can only insulate one of the six walls in a box house, the most important one is the ceiling/attic. This wall is where a house loses the most heat energy in the winter months. 

On a rental unit, there is not necessarily much financial motivation to insulate well, because the tenant is generally responsible for the bills. However, weatherizing a home is always a good thing to do. 

Lucky for the Oregon, the Energy Trust of Oregon provides incentives for homeowners to install R-38 insulation in the attic.  This is a rebate check that I recently received from the Energy Trust for converting from basement electric heating to ductless minisplit. 

Insulating the at attic with blow-in fiberglass insulation was a fun job. It was satifsying to fill up the attic with insulation using a machine that acted like a snowblower. I hired someone to e dump bags of insulation into the blower. I used the 4" wide hose to spray the insulation around the attic. I had to wear a white jump suit and a gas mask to avoid getting fiberglass dust all over me.

Here's a before and after picture of the attic. 

When we were done, we had blown in 18" of insulation, sufficient to meet the R-38 standard that the Energy Trust of Oregon requires to qualify for a rebate. I hope to eventually get a check for approximately $450 for doing this work. The actual material and out of pocket costs were closer to $650. So, while the rebate won't entirely pay for the retrofit, it covers the majority of the cost. The additional savings will come in the form of saved utility bill expenses.