A Japanese charity that turns empty homes into housing for single mothers has won a major international award, drawing attention to the stigma and challenges that such women face in the wealthy nation.

Little Ones, based in Tokyo, was named a World Habitat Award winner on Thursday for converting vacant and abandoned houses into homes for single mothers at subsidised rates.

The non-profit has helped more than 300 single mothers find a home in Tokyo, Osaka and Chiba since its inception in 2008.

"Japan has a culture that makes it difficult for women to work after having children, which makes life exceptionally hard for single mothers," said Little Ones' chief executive Kunihisa Koyama.

Image: Bloomberg

"Apartment owners often refuse single mothers because they are not considered financially stable. The social stigma, lack of economic opportunities and high costs in cities like Tokyo mean the majority of single mothers live in poverty," he said.

Japan is among the world's wealthiest nations, yet its single mothers are amongst the worst off. Fewer than half receive alimony, and many are often unable to work.

The child poverty rate for working single-parent households in Japan is the highest among wealthy nations, according to the Organization for Economic Cooperation and Development (OECD).

Japan's single-mother households rose by about half to 712,000 between 1992 and 2016, the ministry of health said.

At the same time, empty and abandoned homes are a growing problem in the ageing nation, totalling 9 million homes, or about 14 percent of the housing stock.

By 2033, it is estimated that about one-third of Japanese homes will be vacant as the population declines.

A 2015 law to promote the reuse of abandoned houses, has enabled Little Ones to work with owners and local authorities to renovate such homes more easily with a government grant.

"For a single mother and her children, safe and affordable housing is a starting point, so they can move forward in their lives," Koyama told the Thomson Reuters Foundation.

Little Ones also provides a support network and other resources to the women, he said.

The programme is an "ingenious" use of vacant homes to address the "stigmatisation and discrimination single mothers experience in access to housing", said Leilani Farha, the United Nations special rapporteur on the right to adequate housing.

By renovating abandoned homes and bringing them back into use, the project is "physically improving neighbourhoods for the community at large", the World Habitat Awards advisory group said in a statement.