European children spend approximately 200 days a year at primary school. Even though the academic year in most parts of the world is not as long as in Europe, the place where children and adolescents spend the most time, following their own homes, is usually in educational institutions. These can be places for learning, playing and socializing, and as sad as it may be, they can also be safer places for children living in environments of abandonment, hunger, and violence, providing them with opportunities and even meals. A United Kingdom-wide survey found that the differences in physical characteristics of classrooms accounted for 16% of the variations in learning progress over the course of a year. In other words, the better a classroom is designed, the better children perform academically. According to the study, the factors that most affect children are sunlight, indoor air quality, acoustic environment, temperature, the design of the classroom itself and the stimulation within it.