When Gov. Andrew Cuomo released his executive budget proposal last week, New York’s charter school advocates were quick to offer support.

The pro-charter group StudentsFirstNY said the plan reaffirms Cuomo’s belief in the “critical role” of charter schools. New York City’s Charter Center said it sets the stage for “continued growth.”

Why are they excited? The budget proposal includes a few significant perks for charter schools — particularly those in New York City, where more schools would be allowed to open in the coming years.

Here is a breakdown of the changes:

New York City’s charter-school cap eliminated

State law currently allows for just 30 more charter schools to open in New York City — but that number may soon skyrocket.

New York state currently has a statewide charter school cap and a cap specific to New York City. Under Cuomo’s proposal, New York City’s charter cap would be eliminated, leaving just one overall cap on charter schools across the state.

That’s significant because New York City only had those 30 charter slots remaining by November 2016, according to the Charter Center, though there were 126 charters left to issue throughout the state.

The legislature last adjusted the cap in 2015, when it gave the city another 50 slots.

More help paying for private space

As New York City’s charter schools expanded rapidly under former Mayor Michael Bloomberg, many were given space in the city’s public school buildings. Some, though, were told they would have to find and pay for space themselves.

Charter advocates won a big victory in 2014 when the state passed a law requiring New York City to help charter schools pay for private space. Under Cuomo’s new proposal, those schools would get a little more help.

Under the 2014 law, new and expanding charter schools that don’t get public space are entitled to either 20 percent of their per-pupil tuition rate or their total rent, whichever is less. Cuomo’s proposal would increase that to 30 percent of per-pupil tuition rate or the school’s “total facility rental cost.”

The problem for charter schools is that moving into a private space often costs more than the the rent or the 20 percent figure, said David Umansky, the CEO of Civic Builders, an organization that helps charter schools find and build spaces. When that happens, schools face tough budgetary choices, he said.

“It’s not about building the Taj Mahal. It’s about just finding a space to teach kids,” Umansky said. “It’s a real stress on schools.”

Under the law, the city is on the hook for up to $40 million in rent. Once it hits that figure — which the Charter Center estimates will happen sometime this year — the costs will be split with the state.

More public space all at once

Another change requires charter schools to be given enough room for a chunk of grades in the space they are offered. For instance, the city could not give a new charter school one year of co-located space for just a first grade when the charter school has approved plans to expand up to fourth grade.