New insulation, for your home or a commercial building, can mean lower utility costs as well as better sound insulation. It can also protect your home or other building from potential damage due to heat and humidity getting trapped inside, which might allow wood and other such materials to absorb this moisture and then rot, warp, or allow mildew to form. When you're ready for new insulation, note your options and then discuss your choices with a contractor as needed.
1. For minimal interference with the building
For new construction, you can choose just about any type of insulation no matter how it's applied. However, if your home or commercial facility is already constructed, you might opt for spray foam or mineral wool. These require just a small hole in the wall for the spray nozzle to reach. If you do choose either option, you always want to ensure you have a contractor do this or you know how to apply it correctly; the foam typically expands once sprayed, so you can actually spray too much and have pressure on the walls from the underside, warping them.
2. Lower costs
Fiberglass is usually the lowest costing insulation material available, and it comes in rolls, batts, and even spray form. Note that rolls and batts won't cover every small crack and crevice in walls, so it may not be the best for very drafty homes or buildings, or for sound insulation. However, its initial cost can mean that you might afford to add it to areas of your building that you had not planned on insulating, such as around plumbing pipes or even a hot water heater.
3. For soundproofing
Mineral wool offers some of the best soundproofing properties, so it's a good choice in noisy office buildings and for homes located near high-traffic areas, airports, and the like. Since it is usually applied in spray form, it will fill in all those cracks and crevices behind walls and you can even apply it around vents and ducts that carry sound, for maximum quiet.
4. For maximum insulating properties
If your budget is not a concern and you are constructing or renovating, you might consider rigid board insulation. This is a type of foam board that is applied to the studs or framing of the walls; this board usually has the highest insulating factors. It does need to be covered over once installed, so this will mean adding drywall or another material when the insulation is in place.