As the city works to create thousands of additional pre-kindergarten seats this year, officials are searching far and wide for places to put them, Deputy Mayor Richard Buery said Tuesday.

As the city scours public school buildings for classroom space and sends real estate brokers to find private options, officials were disappointed that few charter schools signed up to add pre-K seats, Buery said during a panel discussion that also touched on mayoral control and teacher evaluations. Meanwhile, the city expects some existing pre-K providers to pull out of the program next year because they have struggled to meet the city’s standards, another official said.

“Real estate is always at a premium in New York City and certainly, this expansion, a lot of it comes down to real estate,” said Buery, who is overseeing Mayor Bill de Blasio’s marquee initiative to create over 70,000 full-day pre-K seats by next year. The city has already grown the program to include more than 53,000 slots.

Buery said that student safety is the city’s primary concern when approving new pre-K sites, which operate both in public schools and privately run community-based sites. To that end, the buildings, health, fire, and education departments conducted thousands of site inspections last year in an “unprecedented” show of inter-agency coordination, he added during a talk hosted by the political news organization, City and State.

Still, he said there remains a “wide disparity” in the quality of the various pre-K sites. In September, the city blocked nine new sites from opening and delayed the launch of 36 others because they did not meet health and safety standards. The city will review the sites again at the end of the school year, when it is likely that some will withdraw from the pre-K program because they cannot meet the city’s standards, Department of Education Chief Strategy Officer Josh Wallack said during the talk.

To make room for the next wave of new pre-K seats, the city is looking inside school buildings and “literally having real estate brokers out in the streets of New York City working with local elected officials to see where are there spaces,” Buery said. It is also helping interested community-based sites get up to code, he added.

Nonetheless, “there isn’t a quick fix to this,” he said. “This is New York City, families lives where they live, and real estate is what it is.”

Despite the city’s search for space and qualified providers, only six charter schools are participating in the city’s pre-K program. Even though many charter schools are eager to serve younger students, some are reluctant to give up a portion of their autonomy to meet the city’s requirements, while others may be turned off by the payment and contract issues some charter pre-K providers have faced, as reported by Capital New York.

“I was hoping more would apply,” Buery told NY1’s Lindsey Christ, who moderated the panel. He attributed the dearth of applications to the fact that many charter schools are busy trying to open new schools or make curriculum changes, but said he expects “large, broad participation by the charter sector” in the pre-K program eventually.

De Blasio’s ability to pull off a major initiative like the pre-K expansion depends partly on his control of the city school system, which the state first granted to Mayor Michael Bloomberg in 2002. That law, which was renewed in 2009, will expire this year. Gov. Andrew Cuomo has said he wants to extend it again, and Buery said Tuesday that he expects the state legislature to go along with that plan.

“Of course we want mayoral control to be renewed, with every expectation we have that it will be renewed,” he said, calling the law “critical” for city policymaking. Chancellor Carmen Fariña made similar remarks to lawmakers in Albany earlier this month.

But Buery said there are “a number of substantive disagreements” between City Hall and the governor’s office over the question of how to evaluate teachers. In her testimony in Albany, Fariña said she “absolutely believes” that Cuomo’s plan to increase the weight of test scores and bring in outside evaluators to rate teachers “is not a good idea.”

Buery echoed that sentiment on Tuesday, saying the evaluation system should be “authentic and meaningful” and should not “overstate or understate the importance of tests.”