Despite Boston being a national leader in creating affordable housing, city officials have struggled to meet the rapidly growing demand of city residents, prompting Boston Mayor Thomas M. Menino to announce on Monday a $16 billion housing plan  to build more than 30,000 new housing units by 2020.

Lisa Pollack, spokeswoman for the Department of Neighborhood Development for the City of Boston, said only a third of housing created in the last 10 years has been affordable.

“The city of Boston in many ways is a victim of its own success,” she said. “Lots of people want to come live here, and with 100,000 new jobs to be created by 2020, we need to do more [in terms of housing.]”

25,000 housing units will be private market rate units, 5,000 housing units will be built to expand the supply of housing affordable to the middle class and 5,000 units will be for affordable, deed-restricted housing, according to aMonday press release from the mayor’s office.

Thomas Farmer, spokesman at Massachusetts Housing Finance Association, said Menino’s housing plan will attract more professionals and working families to come live in Boston.

“Mayor Menino is a national leader when it comes to creating affordable housing and recognizing the importance having an affordable home to live in has on our citizens and our economy overall,’’ he said. “His plan to add many thousands more will help make Boston a more affordable city to live in and will attract more professionals and working families to live and work here.’’

Menino said in a Monday press release that creating appropriate housing for residents is necessary for the future of the city.

“Boston 2013 is thriving and well positioned to meet its bright future,” he said. “But one thing has not changed: in order to fulfill its promise, we must stay focused on creating housing, because this is an issue that affects every Boston resident. We do not simply need to put roofs over peoples’ heads, we need to think carefully about the right kind of housing for our changing city.”

Pollack said the lack of affordable housing in Boston thus far is crushing the middle class.

“Because we’re seeing less federal funding and there are 34,000 college students living off campus and driving the rent up in places like Allston and Fenway, the 23,000 families at low-income levels are at risk of becoming homeless because they’re paying more for rent,” she said.

Pollack said universities in Boston have been a huge factor in worsening the problem in the affordable housing effort.

“We need to start getting universities to formally think about the impact they have on the housing market and to work with them to create strategies to help reduce their impact on the housing market,” she said. “We need to drive the cost of housing students on-campus down and make it a more reasonable and affordable option for students [so that they don’t move off-campus].”

Randall Ellis, professor of economics at Boston University, said the cost of rent will go down if the housing supply is increased.

“Rents in Boston are high because Boston is a very attractive place to live,” he said. “Building more housing will help lower these rents and make more units available, including for students.”

Although more housing will also increase the need for services, Ellis said these totals should not increase the cost of housing.

“Increasing the housing in the city will help BU and other students,” he said. “Of course, more housing also means more services, but since the area of Boston is fixed, generally these costs go up less than in proportion to the size of the population, and taxes on existing houses should go down.”

Pollack said Menino’s efforts so far have transformed affordable housing in the city.

“Under the mayor, Boston has become a national leader in affordable housing,” she said. “Boston has the most percentage of affordable housing in the United States, but there is still a lot of work to be done.”