Alternative housing is a category of domicile structures that are built or designed outside of the mainstream norm e.g., town homes, single family homes and apartment complexes. In modern days, alternative housing commonly takes the form of tiny houses, dome homes, pyramid-shaped houses, earth sheltered homes, residential tree houses, abandoned factories and hospitals and even up-cycled vans or buses. The motivation to create alternative homes can arise from destitution or lack of resources to buy or rent a typical home and therefore include improvised shacks in shantytowns, buses, cars and tent-like structures.

While the cost of living in an alternative house can be more economical than a traditional home, the start-up cost can be quite hefty. More commonly in the 21st century than ever before in history, alternative housing offers more functionality to many, as well as an unconventional living arrangement. Some alternative housing can be as small as 500 square feet (46 m²) while others can be as large as 5,000 square feet (460 m²) depending on the structure. Alternative housing, much like common housing, usually offers an area for cooking, sleeping, bathing, and an overall living space.

One of the first popular uses of alternative housing in modern times was during WWI and the Great Depression. During the Great Depression, many people ended up losing their homes. More than 15 million people were out of work at the time, and desperate for housing. Due to the vast influx of homeless people, the creation of Hoovervilles took place. Alternative housing at the time was used as a way of living to save money, and to do that, people built shanty homes. As time went on, people began to take ideas learned from shantytowns and put them to use in other forms of alternative housing.

In contemporary society, alternative housing is moving from last resort housing to an option that people choose in the face of a housing market that is getting more and more costly ^{[citation needed]}. With the rise of social media, more and more people were exposed to the idea of alternative housing, and its popularity grew. Paired with an increase in spendable income, the choice to live differently grew stronger.

Social media can be attributed to playing a major role in the rise in popularity of alternative housing. Sharing pictures, videos, and information about alternative housing spreads knowledge about the concept. During the early days of Instagram, a young couple became a lifestyle brand with millions of followers all because of their living situation; living in a van. The artistry and mindset of van living drew in Instagram followers, and led to a movement of people following suit under the hashtag #vanlife.

Facebook is another example of social media influence. A survey conducted in Australia has found that there is an increasing trend in people wanting to own a tiny home, specifically in older women. The trend is argued to stem from growing Facebook pages, as one has more than 50,000 followers. Facebook groups allow people interested in alternative housing to connect with each other to make the process easier.

Alternative housing around the world, while on the rise, has not yet reached the heights of popularity as it has in North America. Most of the alternative homes across the world tend to be adaptive/reuse homes. These types of homes/building tend to be derelict or unused buildings (hotels, factories or hospitals) that are converted into low-income housing, green sustainability communities, schools or hotels.

The Australian Government's Department of Environment and Heritage published a report that found that reusing a building's material for a new purpose has a 95% savings of "embodied energy" that would be otherwise wasted. This "embodied energy" is by the Australian government as "the energy consumed by all of the processes associated with the production of a building, from the mining and processing of natural resources to manufacturing, transport, and product delivery."