How light and shadow could be used as building materials in architecture There is no need for defining natural light; however, what one needs to remember is that natural light allows people to define what is around them, by night and by day: the altering perception of the bodies or things on which it impacts, as well as the space that contains them. Generally, natural light or its absence could also transform this space in every moment, every day of the year, every season and every hour (Johnson 17). There are various ways in which light and shadow can be employed as material in architecture.