There is a draft whenever you go upstairs or you feel it in your bedroom. You might look into replacing your windows and think it will save you your energy bill and make the home warmer. Good energy efficient windows do stop the draft, and if they are properly sealed/caulked around, but as you know replacing those windows would/can cost quite a handsome amount and your house might still remain drafty.
What many of us don’t know is the fact that most of your energy is not lost from the windows, it is actually your attic that is loosing the heat mostly (heat travels upward), and insulating your attic would save you (estimated) 10 to 50% off your energy/heating bill.
A DIY insulation is not as hard as one would think, one would definitely need 2 people to do the job, but firstly, one has to measure how much “R-value” there is in the attic. Go to a Home Depot or any other home hardware store and ask the associate for a paper measure which shows the R-Value of your attic, they are free, and one can get them from the rental center. The current standard of attic insulation is R-50, which is about 16″ of blown-in mineral fiber. If your attic has 10″ of insulation or less, adding more insulation should be considered.
Before you climb up to the attic, wear a mask and gloves, the insulation and dust can be allergic to some people and it is not one of the best place to work without protection. Be careful about vermiculate insulation. Once you have climbed into your attic with the help of a ladder, find a joist to stand on and from the bottom of the drywall in attic, measure where the pink insulation raises to. Determine how many inches you need to reach to the certain limit, the paper measure you got from Home Depot will help, also measure how big your attic is, then multiple length with the width in feet.
Now that you have an estimate, take it back to the home hardware store and the associates would be able to help you to find out how many bags of insulation (pink stuff) one will need, and if one gets 10 bags of it, the machine to blow the insulation might be free. This is where one will need the other person to load the machine while one is blowing the insulation into the attic. Make sure you choose a warm and dry day to do the job.
There is also a video that is posted on youtube on how to use the attic cat machine that Home Depot provides. Happy insulation!