A new policy on public rental housing is allowing more low- and middle-income families to apply for homes. But people without Beijing hukou - permanent residence permits - must wait for more details to be released before they can take advantage of the change. The policy, which took effect on Thursday, also pertains to larger local families with three or four members and allows residents without hukou to apply for those documents if they have worked in the city for an as yet undetermined number of years.

"In addition to the amount of years they have been working in Beijing, a limit on annual income will be set later," said an official from the Beijing Municipal Committee of Housing and Urban-Rural Development, who declined to be named. "Because some residents said it's only fair that they should have the same restrictions as local families."

The precise restrictions on migrant people will vary by district depending on an applicant's situation and the number of candidates and public rental units in the district. The districts will later release detailed guidelines.

Some migrant workers had lost hope of being able to get government-subsidized housing because they feared they would not be eligible for it or that they would have to wait too long.

"It's too complicated and most of these units are far from the downtown, which means spending more time on the road, so I gave up," said Zhang Lifeng, a technician renting an apartment near Zhongguancun with a friend.

Yin Bocheng, director of the real estate research center at Fudan University, supports restricting applications according to the amount of time an applicant has spent on the job.

"Because of the limited supply of these units, it's necessary to narrow down the number of the applicants," he said on Thursday.

But the restrictions should be flexible and change according to different situations, Yin said. He added that although applicants might at first become eligible after three years, for instance, as the supply later gets larger and applicants fewer, that time could be shortened.

Though some people without hukou disapproved of the new policy, many others and local families welcomed the measure.

"Although it snowed today (Friday), more than 200 people have come to the office for information on public rental units in the first two days of the new policy," said Yang Pingrong, director in charge of applications at the Desheng Subdistrict Office. "We got hundreds of phone calls; our consultants were almost breathless answering questions."

By noon on Friday, more than 100 qualified candidates had applied for government-subsidized affordable housing.

"It's much easier for me to pay hundreds of yuan to rent an affordable place from the government than to spend tens of thousands of yuan to buy an apartment, even one that's cheaper than commercial ones," said Wu Jingli, 54, who missed an opportunity to buy a government-subsidized apartment two years ago because it was beyond her means.

"If I can rent a unit by myself, I'll have a place to live with my 22-year-old daughter again." she said. Since divorcing, she has lived in a small apartment with her parents, who are in their 80s.

A woman surnamed Song arrived at the office about 8 am on Thursday to apply for public housing. "I really need the cheaper place to save money for my daughter," she said.

Shanghai, which is facing the same burgeoning migrant population without hukou, also has a policy to allow them in June to begin applying for the public rental housing units.

In Chongqing, about 200,000 square meters of public rental units will open to migrant workers by the end of the year.