Before anyone considers “going solar” you should minimize your energy demands. The biggest energy demand of any household is heating and cooling. So what is “R-value anyway.
R-value is a measure of thermal resistance (K·m²/W) used in the building and construction industry. (wikipedia)
As everyone should know, the bigger the R-value the better. But what is a good standard number? When my house was built R-19 was energy star for the walls and R-38 for the Attic. Now the new house standard have increased. Does this mean my house is not as good anymore? Well, not exactly. The R-value recommendations are made from a cost standpoint. That is to say, R-70 in your attic would be just fine but after R-49 you are just wasting your money. This is more commonly referred to as, point of diminishing returns. Your payback will be longer and longer the more insulation you add. Not a big deal if you plan on staying in your house a long time.
If you can afford to put more R into your home, you will get more money out in energy savings. These saving have been proven to increase the value of your home too. Don’t forget that the feds are will to provide you with a tax credit to boot.