financial evaluation.

Each increase of energy tariffs actualizes the problem of insulation of buildings in order to reduce heating costs. This raises the question of choice of insulating material. In the article is considered the actual question comparing the most common types of thermal insulation - polystyrene (foam) and mineral wool. As a general criterion of comparison proposed life cycle assessment which is formed of four stages assessments existence of material: manufacture, installation, use (operation) and return back to the environment.