You don't need a lot of money or space to live comfortably. Well, if you don't mind living in a small space, that is. Here are some of the world's smallest homes found in buildings, on roofs, on wheels, and in backyards. It looks claustrophobic, but it doesn't seem to bother their owners who have found comfort in these tiny spaces.

1. This apartment transforms into 24 different rooms.

Location: Hong Kong, HK
Size: 330 sq. ft.

Living spaces in Hong Kong are unsurprisingly tiny, so Gary Chang, and architect, turned his family's tiny apartment into a sleek and efficient living space with 24 different room combos, including bathrooms, kitchens, living rooms and even a guest bedroom area.

Chang did this by installing a number of sliding panels which he can move around to reveal hidden areas and storage. He calls this system the "Domestic Transformer."

2. New York City is getting 300-square-foot micro apartments.

Location: New York, USA
Size: 300 sq. ft.

New York City Mayor Michael Bloomberg revealed a plan last July, to create studio apartments that would be no bigger than 300 square feet. The apartments were to be constructed in the Kips Bay area of Manhattan, and they would be an affordable housing solution for young professionals. It could hold a kitchen, bathroom, living area and sleeping area. Its affordability is, however, debatable: it would cost around $2,000 a month to rent!

3. San Jose, too, is getting its own 300-square-foot micro apartments.

Location: San Jose, California, USA
Size: 300 sq. ft.

The San Jose Department of Housing recently built a development of 42 affordable single room occupancy apartments, each being 300 square feet or less. Each unit is the size of two parking spaces, and it'll include a full kitchen, bathroom, and a combined living/sleeping area. At a price of $650 a month, it seems worth it.

4. Twelve Cubed is a company that makes 10- and 12-foot cubed housing units.

Location: Vancouver, British Columbia, Canada
Size: 288 sq. ft.

James Stuart founded Twelve Cubed after learning of a homeless woman who died in her cardboard shelter on the streets of Vancouver, when her cardboard home caught fire. Twelve Cubed designs and manufactures 10x10x10-foot and 12x12x12-foot homes.

Each home is up to 288 square feet. It has two levels, has a bed, living area, desk area, kitchen, and bathroom. It can even come equipped with a washer, dryer, and dishwasher! Stuart himself lived in one of these units for eight months to prove it could be done.

5. Once a pigeon loft, this little space in Barcelona is now a little home.

Location: Barcelona, Spain
Size: 258 sq. ft.

Photographer Christian Schallert moved to Barcelona in 2003, and was looking for the perfect, affordable home. He found an old pigeon loft atop a building, about 100 steps up. He converted it into a warm, open, "Lego-style" apartment. The walls slide to reveal different room setups. The panels move to hide his kitchen, closet, bathroom, dining room, and living room. The bed is stored under the terrace balcony that overlooks the city of Barcelona.

6. San Francisco is getting micro apartments meant for two people.

Location: San Francisco, California, USA
Size: 220 sq. ft.

Last November, San Francisco's Board of Supervisors approved plans for 220-square-foot apartments, with the one condition that they cannot be occupied by more than two people.

375 units of these apartments will be built to help manage the affordable housing crisis in San Francisco, where the average studio currently rents for $2,000 a month. The new micro-apartments would rent for $1,200 to $1,500 a month, which is considerably cheaper, but still a lot considering the size of the apartment.

7. A Yale student built a 144-square-foot environmentally-friendly home.

Location: New Haven, Connecticut, USA
Size: 144 sq. ft.

Elizabeth Turnbull built her own 144 sq-ft home instead of opting for university housing when she was accepted into Yale's School of Forestry and Environmental Studies.

Turnbull made sure to consider the environmental impact her home would have to minimize any potentially harmful effects by using all FSC-certified wood, non-toxic paints and finishes, and recycled windows.

8. This is a 112-square-foot mobile house that traveled across 9,000 miles.

Location: Around the USA and Canada
Size: 112 sq. ft.

Zach Griffin and four friends decided on an epic, cross-continental ski trip. So they built a 112-square foot mobile pod house where they lived for six weeks.

It has a "drawbridge" bunk bed that comes down from the two-person sleeper loft, and a pull out sofa bed. They relied on hostels and strangers for bathrooms, as the pod had none. But it did have electricity, a generator, a toaster oven and a propane stove as their kitchen.

9. This simple 104-square-foot home is beautifully designed.

Location: Seattle, Washington, USA
Size: 104 sq. ft.

Chris and Malissa Tack wanted to leave their complicated, material lives behind. They started by living in a smaller, simpler home. This home cut their living cost substantially, and they predict the home will be paid in full in just two or three years.

10. This environmentally-friendly home will actually earn you money.

Location: Edinburgh, Scotland
Size: 100 sq. ft.

Called the "Eco-cube," this 10 ft cubed is sizeable enough to hold a small living room, dining area, kitchen, washer and dryer, a closet, full shower, toilet, and full-sized bed.

Designed by Dr. Mike Page of the University of Hertfordshire, this was an initiative created to prove that a person could "live a comfortable, modern existence with a minimum impact on the environment." With solar panels, the Eco-cube can earn you $1,600 a year through the UK’s feed-in tariff.

11. This Manhattan studio is only 90 square feet.

Location: New York, USA
Size: 90 sq. ft.

Felice Cohen pays a little over $700 for this tiny apartment in Manhattan, where typical studio rent would cost an average of $2,569 per month.

Cohen is a writer and professional organizer, and she's made efficient use of the space with high, narrow storage units and a lofted bed that is just 23 inches down from the ceiling. The studio has no real kitchen, but Cohen has a toaster oven and mini fridge, which she restocks a couple of times a week. The bathroom is surprisingly a decent size.

12. This 89-square-foot home has an "entertainment area," a kitchen, and even a fireplace.

Location: Sebastopol, California, USA
Size: 89 sq. ft.

Jay Shafer is the founder of the Tumbleweed Tiny House Company, which constructs small homes ranging from 65 to 874 square feet.

Shafer's own house is 89 square feet, but it has an "entertainment area," a kitchen with plumbing, a working fireplace, shower and toilet, lofted bed, and shelves on almost every wall.

13. This 84-square-foot home cost only $10,000 to build, and even less to maintain.

Location: Olympia, Washington, USA
Size: 84 sq. ft.

Dee Williams came home from an inspiring Guatemala trip and decided to downsize her home from 1,500 square feet, to a mere 84-square feet. She moved out of her large space, and built a tiny one from scratch, in her friend's backyard!

She calls it "The Little House," and it cost about $10,000 to build. She uses a propane tank for heat, and solar panels for electricity, so she pays very little to live there.

14. This 80-square-foot home was listed for a whopping $145,000.

Location: London, England, UK
Size: 80 sq. ft.

This 8 x 10 foot London apartment is located in a prime location, near the famous Harrod's department store on Brompton Road.

The location is most likely the reason for its steep price: The flat was originally listed for $145,000, but more than a dozen offers have been made on the tiny pad. The highest bid is believed to be $280,000 so far, according to CNN Money. How crazy is that?!

15. The UK's tiniest house it probably this 60-square-foot home.

Location: Conwy, Wales, UK
Size: 60 sq. ft.

The Quay House is this tiny red home that measure only 10 x 6 feet. It's known to be the smallest house in the UK, and has actually become a tourist attraction in Conwy, Wales.

It's been occupied by various people since the 16th century, including a 6 ft 3 inch fisherman. The home has room for a stove, water tap, bed, and bedside storage.

16. China is building 50-square-foot apartments which are meant for two people.

Location: Wuhan, China
Size: 50 sq. ft.

Housing is becoming more difficult to come by in the city of Wuhan, China. So the city is building 50 sq ft capsule apartments which are meant for two people.

A six-story building in China’s Hubei Province has been divided into 55 separate capsules, each of which functions simultaneously as a bedroom, living room, bathroom and kitchen. The apartments primarily house young adults.

17. This 5-foot-wide home in Poland is the world's skinniest apartment.

Location: Warsaw, Poland
Size: 46 sq. ft.

Polish architect Jakub Szczesny built this tiny home in an alley between two buildings. It doesn't have any windows, but it has a shower that aims almost directly over the toilet. It also has a tiny bedroom, and a little kitchen which has a fridge that only has room for something like two sodas.

18. This small home in China is built on top of a tricycle.

Location: Beijing, China
Size: About 33 sq. ft. when folded

This unique polypropylene mobile home is to small that it can be folded up, accordion-style, and carried around on the back of a tricycle.

Designed by Beijing's People’s Architecture Office and People’s Industrial Design Office, the expandable home can attach to others for more space, or to portable gardens to give the appearance of a "yard." Its facilities include a sink, stove, bathtub, and water tank. All the furniture is convertible: the bed turns into a dining table, the countertop  becomes a bench for seating, and it can all fold up into the front wall.

19. This 15-square-foot bike camper home was designed to be a residence for the Burning Man Festival.

Location: Black Rock Desert, Nevada, USA
Size: About 15 sq. ft.

Designer Paul Elkins needed a convenient and eco-friendly way to get around during the Burning Man Festival, so he created this wind turbine-powered bicycle camper that functions as a bedroom, living room, and kitchen. And it's even got a solar-powered oven!

20. This Berlin home, at 11 square feet, is the "world's smallest house."

Location: Berlin, Germany
Size: 11 sq. ft.

Architect Van Bo Le-Mentzal build this 1 square meter (11 square foot) house which is light enough to lug around on its wheels. It provides just enough room to sit or lie down and sleep (when tilted on its side).

Le-Mentzal says he designed the structure to make people think about the way they define the concept of "home".