New York's first micro-apartment block features ultra-small digs

A possible solution to New York's increasing over-crowding problem has been unveiled as "micro-apartments", a collection of tiny blocks measuring as little as 23 sq m each.

Mayor Michael Bloomberg has announced the winner of the design competition the city held to find a way to cram more people into less space.

The winning design team – comprising Monadnock Development LLC, Actors Fund Housing Development Corporation and nARCHITECTS – plan to complete the block of 55 units by the end of 2015.

Each apartment features 3m-high ceilings, a full kitchen, lounge area, bedroom and balcony, but measures only between 250 and 370sq ft (23 to 35sq m).

That is little more than two average-size shipping containers.

The designers can cram all those features in because the rooms are made to change so they can be used for different things.

For example, the bed can fold away to be replaced by a couch when entertaining guests.

They also use large windows, lofts for storage, and juliet balconies which do not protrude from the building.

Mr Bloomberg says the city has a shortfall of 800,000 apartments and it's only going to get worse, according to the New York Times.

The 10-storey-high apartment block will also be the city's first to use modular construction – the units will be made off-site and then stacked on top of one another like shipping containers.

The apartments are meant to be an "affordable" option – 40% will be reserved for people earning between $US48,100 and $US93,310 a year.

Rent for those will be between $US939 and $US1873 a month.

The rest will be sold at market rate – the average monthly rent for a studio in December was $US2282, Bloomberg says.

New York normally does not allow apartments of less than 400sq ft to be built, but made an exception for this competition.

San Francisco has tried to tackle its space problem more aggressively by approving a block of apartments, each as tiny as 220sq ft (20sq m).

A similar project is under way in Boston where several hundred 300sq ft units are being developed.

The trend has been occurring in many of the world's large cities, including London, Vancouver and Tokyo.

In Madre de Deus, Brazil, is an apartment 10m high and just one metre wide.

Designed by Helenita Queiroz Grave Minho, who lives in it, it has two rooms, a kitchen, three bedrooms with bathrooms and a veranda.

Compact-design has also made its mark in Toronto, where the city's "little house" was built between two existing houses, although it was not built because of modern space constraints.

Measuring just 312sq ft (29sq m), it was built in 1912 by developer Arthur Weeden.