One of a classroom’s most critical physical design characteristics is lighting. Even the thought of dull hum and their pulsating flicker can produce a melancholy feeling or even a slight headache for some students. According to R.G. Barker (1968), windowless classrooms do not promote success in students. From an architectural standpoint, windowless classrooms can be useful to save resources such as material and building supplies. Windowless classrooms are also designed to reduce distractions and heating costs. However, the absence of windows in the classroom has some serious overlooked side effects. A study (Ahrentzen et al., 1982; Karmel, 1965) showed that students' moods are more negative in windowless classrooms. The study also showed that while a few students improved without windows, most others showed a decrease in academic performance in the windowless settings. Fielding (2006), found that in natural lit classrooms math scores improved by 20 percent and verbal scores by 22 percent. "Natural light is perhaps the single most important element in the learning environment." says Fielding.

The size of a classroom can have profound effects on students for many reasons. For example individuals from different cultures vary in their preferred inter-personal distances during conversation. Mark Kantrowitz, an expert on the effect of cultural differences on the education system, states that every student has an “invisible boundary” around his or her body, often referred to as “personal space” (Kantrowitz, 2008). If someone pierces this boundary, the student will feel uncomfortable and step back. Kantrowitz goes on to discuss how the preferred personal distance varies widely from culture to culture, leading to confusion in culturally-diverse American classrooms. Often, classrooms are overcrowded which force invasions of personal space between students. An article by Sarah Garland in the New York Sun published a survey taken from teachers by the United Federation of Teachers talking about the overcrowded classrooms. “There were 1,719 overcrowded classrooms in elementary and middle schools as of September 19, up from 668 last year. Including high schools, there were 6,339 overcrowded classrooms in total, up from 5,761 last year,” (Garland, 2006) suggesting that overcrowded classrooms are increasingly common.

Overcrowding not only affects the physical learning environment by forcing invasions of students' personal spaces, but also reduces instructors’ abilities to give adequate attention to each individual. Needless to say if the student is not receiving as much attention as others, their academic performance will be affected. It is evident that spaces and places can evoke emotional response and elicit or inhibit behavioral responses said D.M. Garret. Garret showed that students in an open classroom space and more personal space demonstrated a tendency to exhibit less disruptive behavior in school and students in traditional schools tended to be more disruptive in class. Clearly it is important for interior design planners to increase the amount of square footage per student in the construction of today's schools (Garret, 1980).

Color is an essential classroom feature, for it can drastically impact the learning process.  In a study by Knirck, the impact of color in the learning environment has been proven. Knirck found that color has the capability to influence a student's attitude, behavior and learning process. He concluded these findings for several reasons. The study suggested that the proper use of color in a classroom environment can change the mood of students. Knirck’s study demonstrates that color is intensely powerful— it promotes ardent positive or negative emotions about one’s environment. Warmer colors, such as reds, oranges and yellows, were shown to cause a slight rise in blood pressure by promoting a feeling of warmth, while the cooler colors, greens, blues, and purples caused a slight decrease in blood pressure. Colors can also alter the appearance of room size; by making it seems more compact or more spacious than it is in actuality.

It has also been shown that certain colors can increase student’s auditory-verbal memory skills (Rustigan, 1992). This would certainly be beneficial during the common activity of professors lecturing to students, and through the use of audio books in the classroom. Students who have a more positive attitude toward their learning environment due to the room’s color scheme will learn more effectively, have better attendance and ultimately perform better.

Furniture has definite effects on student performance. Classroom furniture must be both flexible and ergonomic. Flexibility of classrooms is often limited. The classroom environment is usually focused on one objective and purpose. Some will argue that the architectural plan needs to be focused on one objective so that students are not distracted and the teacher has all the attention. According to Owu, "focus is achieved through the arrangement of architectural elements, proper acoustics and lighting"(p15). Though teachers differ greatly as to their preferred arrangements, almost all agree that the days of thirty desks aligned in neat rows in front the teacher's desk are long gone. Polly Curtis, a writer for the Guardian’s education section says, that “schools need to upgrade their furniture because today's children have outgrown the tables and chairs designed to meet the needs of 1960s pupils”. Today’s furniture often uses the same clunky and unduly heavy designs of the 1960s, preventing the easy reconfiguration of classrooms as the learning situation requires. A teacher might want to arrange desks in cooperative groups of four, and then switch to a U-shaped configuration for the remainder of the class, but are prevented from easily doing so by the furniture's weight.

Education administrators often base furniture-purchasing decisions based solely on which is cheapest, overlooking the multitude of other important factors. A study by Dr. Dieter Breithecker explained that it is more taxing for children to sit still. The static sitting posture may cause long-term health issues in children, whose physical development requires more exercise than adults’ less strenuous maintenance needs. Dieter stated that “from their first year in elementary school on, children are exposed to sedentary strain under adverse ergonomic conditions” (Dieter 2009).