env is only useful if the script is going to be used on multiple systems where the location of the binaries can vary. If the script is only used on a single system or in a homogeneous network then it's not necessary.

Of using /usr/bin/env as Sha-bang
My sister's garage gets very cold and very hot as it is not currently insulated. She has the heating/ac unit in there as well as a deep freezer. The attic space directly above the garage has no insulation and the exterior wall is just cinderblock with plaster on the outside of house. All other walls are just cinderblock with a bedroom on the other side with regular drywall.

This racks up the electricity bill as both the ac/heater and freezer needs to compensate for the large temperature difference. Also the garage walls that are part of the interior of house are not insulated, so that breaks the buildings insulation envelope further.

We want to replace her current garage door with an insulated one. We also will be adding insulation to the attic space. So my questions are:


What types of insulated garage doors are available on the market, pros/cons?
How would we insulate the cinderblock exterior wall?
How would we insulate the cinderblock interior walls?

