Housing is the living places for human beings. As the population keeps climbing, people in the city have to face the reality that housing is in short supply. To solve this problem, New York city planners are challenging tradition and starting to design more "micro units".Micros, also known as "hostel-style" apartments, usually offer less than 200 square feet (18.5 square meters) in area. Could you imagine living in 150 square feet (14 square meters)? These units usually have only room for a bed, a table mini-fridge and the basic living essentials.Why is the micro apartment so appealing? The reasons are rather straightforward. It is perfect for the single people who don't have a lot of things. It can also meet the need of people who are short on cash but determined to live in their own places.Micro apartments are very common in cities like Tokyo and Hong Kong, where there are so many people living. Now this tiny housing solution is gaining ground in urban areas in the U.S. and Canada.The micro apartment is an experiment in simplicity in American culture. So small-scale home life is part of a hot trend in U.S. real estate. Some people are proud of it. Some of them can find the humor and fun in their small places. But not everyone is in favor of the trend.