Insulation isn’t just important because it makes a structure more comfortable to live, work, or shop in. Insulation in building construction is also important for the following reasons:
The reason it’s important to cut insulation carefully around fixtures rather than just cramming it in is that the insulation can lose a lot of its efficiency if it isn’t fit correctly. The best way to cut fiberglass panels to size is to use an extended utility knife with snap-on blades. These long, sharp tools are perfect for cutting insulation precisely and without sending a bunch of irritating fibers into the air.
The most efficient way to cut insulation to size is to do it outdoors if possible to avoid any kind of air contamination from the insulation dust. Putting down the insulation against a board also makes it easier to make accurate measurements and cuts.