Isata Jabbie sits at the playground with her children, Raja Samura, 8, left, Mohamed Samura, 6, center, and Ibrahim Mustapha, 3, right, at the Great Hope Homes affordable housing community on June 19 in Silver Spring. (Ricky Carioti/The Washington Post)

Isata Jabbie and her four young children were living in a friend’s crowded Prince George’s County home, where a constant stream of visitors made the arrangement cramped, noisy and unstable.

“I was at the edge of a cliff about to fall off, with all those people,” said Jabbie, 37. “If I go to work, thinking of coming home, I don’t want to come home.”

She started searching for a place of her own in Montgomery County, because she wanted her children to attend the highly rated schools there. But with a low-paying job as a certified nursing assistant, she quickly realized that finding an apartment she could afford would be tough. It took more than two years.

Although Montgomery is an affluent area, many people still struggle to pay for shelter there. Today, more than 10,000 people are on the public housing waiting list, and more than 15,000 are waiting for low-income housing vouchers — lists so long the county closed them in 2008.

Thousands more who are not poor enough to qualify for public housing seek spots in fixed-price, affordable residences known as “moderately priced dwelling units.” They are set aside for families that earn less than 65 percent of the county’s median income — $45,180 for one person, $51,600 for a couple and $64,500 for a family of four.

Now, as the county polishes a major overhaul of its zoning code, the first in 35 years, some worry that the changes will make finding affordable housing even harder.

At the heart of the debate is a benefit for developers called a “density bonus.” Housing complexes can only have so many units, depending on the zoning, but if developers earn a bonus, they can add units. That means they can rent or sell more units and increase their profits.

Currently, there’s only one way for developers of most properties to receive a bonus. The county has long required that in any new development, at least 12.5 percent of the units be set aside as affordable housing. Bonus points are awarded for building additional fixed-rate units, up to 15 percent.

The new zoning code — which is intended to promote neighborhoods where people can live, work and shop without driving — would give developers in many more locations a long list of ways to earn points toward a density bonus. They could, for instance, install public art, put up signs directing passersby to points of interest, create a building with “exceptional design” or one that conserves energy, or they could build close to a Metro station.

“No one’s going to build affordable housing, because we’ve got a million cheap ways to provide density,” said County Council member Marc Elrich (D-At Large), who is among those who say the new code will discourage construction of affordable housing. “You get points for putting up a wayfaring sign, a green roof. It’s ridiculous.”

Elrich said the new plan encourages the expansion of retail businesses in the county but fails to consider appropriate housing options for people who would staff them. “They put retail everywhere, and people who work retail jobs can’t afford the housing to live in the county,” he said.

But Nancy Floreen (D-At Large), who serves with Elrich on the Planning, Housing and Economic Development Committee, which will vet the proposal before it goes before the full council, said she thinks the new zoning code would yield more affordable housing even if developers had no incentive to build more than the minimum.

“What the rewrite is doing is introducing opportunities for more housing generally throughout the county in the commercial zones,” she said. “To the extent that there’s more housing, a certain percentage of it will be affordable.”

And Françoise Carrier, who chairs the Planning Board, which wrote the proposal, defended the additional options for obtaining density bonuses. “Affordable housing is very important, but there are also urban design goals that are very important, and we will whittle away at them if we focus only on affordable housing,” she said.

Still, housing advocates worry and pass around troubling anecdotes. They tell of a couple with eight children who struggled to find enough space at a price they could pay, and of a divorced mother who ended up in a homeless shelter with her disabled child after calls to 50 Montgomery buildings met with no success.

Jabbie considers herself lucky to have found a place. After countless applications and more than two years of dashed hopes, her family finally moved into an affordable townhouse in April.

“I’m still pinching myself,” she said as she recalled the moment she learned that she had been accepted for a four-bedroom apartment in a subsidized development in Silver Spring. “That day was the best day in the whole wide world.”

Hearing about the zoning debate, Jabbie said the county needs to do more to help people like her. “There are a lot of single moms out there struggling,” she said.