The most common reason for sharing housing is to reduce the cost of housing. In many rental markets, the monthly rent for a two- or three-bedroom apartment is proportionately less per bedroom than the rent for a one-bedroom apartment (in other words, a three-bedroom flat costs somewhat more than a one-bedroom, but not three times as much). By pooling their monthly housing money, a group of people can achieve a lower housing expense at the cost of less privacy. Other motivations are to gain better amenities than those available in single-person housing, to share the work of maintaining a household, and to have the companionship of other people.
Housemates and roommates are typically unmarried young adults, including workers and students (the practice of sharing a bedroom is mostly limited to students). It is not rare for middle-aged and elderly adults who are divorced or widowed to have housemates. Married couples, however, typically discontinue living with roommates, especially when they have children.
Roommates are a fairly common point of reference in Western culture, especially in North America. In the United States, most young adults spend at least a short part of their lives living with roommates after they leave their family's home. Therefore, many novels, movies, plays, and television programs employ roommates as a basic principle or a plot device. On the other hand, it is less common for people of any age to live with roommates in some countries, such as Japan.
Many universities in the United States require first-year students to live in on-campus residence halls, sharing a dormitory room with a same-sex roommate. Studies have found that the academic grades, study style, social behavior, and personality of one roommate will affect the other roommate's academic performance.
The change in the cost of housing makes the consideration of roommates more attractive. As the housing market increases, so too does the roommate ratio rate. When house prices drop, the opposite can be expected. This has been seen extensively in cities such as Washington D.C., Phoenix, and San Diego.
Student exchanges are getting more and more popular with globalization and has influenced a lot in the Roommate Boom. The Erasmus exchange program in Europe has contributed as being the biggest exchange program in Europe. Exchange students can live in university residences but a growing amount want to share apartments with other international students in shared apartments.
Roommates and house-sharing are not limited to students and young adults however. American politicians Chuck Schumer, William Delahunt, Richard Durbin, and George Miller famously share a house in Washington, D.C. while Congress is in session.
Another thing to consider when choosing a roommate is how to divide the cost of living. Who pays for what, or are the shared expenses divided between the two or more roomies. Also, the potential roommate should be trusted to pay their share and trusted to pay it on time. Sleeping patterns can also be disrupted when living with a number of people, so it is therefore important to choose housemates wisely.