Nowadays insulation installation means a wide variety of things for different property owners. If the project is new then it’ll probably mean shooting foam in wall cavities. Foam might be sprayed in the attic as well.
If its a renovation it probably means injection foam, or blown in loose fill. And as we’ve been seeing in recent trends, many insulation contractors are using hybrid techniques amongst insulation installers.
There’s fiberglass roll which is the cheapest and easiest to install. But it’s itchy and you can breathe the particles in when you install it.
There’s blown in, which is usually recycled newspapers (cellulose) or sometimes fiberglass pieces (just like the roll but in small pieces).
Reflective is usually used on concrete block wall and it’s like aluminum foil and basically reflects heat and/or cool temperatures.
Then there’s foam insulation which usually means spray foam and its definitely the most expensive and it has perks like being the best insulation for R-Value. And it seals all cracks and crevices forming a monolithic seal with wood or steel studded construction. It’s only useable when the wall is opened up during a renovation or new construction.
Nowadays existing homes want the benefits of foam so a new invention came about called injection foam or sprayed in place foam insulation.