New stores are opening across the city at an impressive pace, many of them in locations now newly accessible to certain businesses because of Mayor Eric Adams’ “City of Yes” rezoning revamped archaic rules.

Construction of new multifamily buildings is also finally picking up, a year after the legislature and the governor finally agreed on a new tax break to spur residential construction amid the city’s severe housing crisis.

And the conversion of obsolete office buildings into much needed housing is surging, spurred by a tax break ed a year ago and the rezoning that greatly expanded the kind of buildings that could be converted.

“The trend is very simple. People are building,” said Carlo Scissura, president of the New York Building Congress. “Office-to-residential conversions will be one of the most successful programs to hit New York in many decades. You have a lot of older office buildings in great locations near transit and it makes sense to see them become residential buildings.”

The activity is a sign that policy changes sought by the Adams istration, real estate interests and pro-housing groups are paying off.

But it comes with a major asterisk. All of the new apartment construction projects expected to use the new 485-x development incentive are for buildings with fewer than 100 units — sidestepping a costly wage requirement for construction workers but also producing less housing than the sites could accommodate.

“The activity is all excellent and wonderful, but we are not seeing enough numbers to say we are making a demonstrable dent in the goal of adding 500,000 new housing units,” said Basha Gerhards, senior vice president of the Real Estate Board of New York.

At least the numbers are headed in the right direction.

The Department of City Planning will announce Tuesday that 500 vacant storefronts reopened in the last year that might otherwise have been shuttered permanently because of restrictive zoning rules that forbade reopening old storefronts in residential areas. (The city tracks store openings and vacancies through a database called Live XYZ.)

The fast-growing amusement sector, which includes arcades and mini golf courses, has taken advantage of the new flexibility.

For example, Activate Games signed a 175,000-square-foot lease at 24 Union Square East, where it will occupy part of the first floor and all of the second floor of a former furniture store at its first New York site. The Canadian company, with 40 locations worldwide, has pioneered a gaming business that combines physical activity with mind games that groups can play, and it could not have opened in Union Square without the zoning changes.

“It’s clear that we made an important change at the right moment,’’ said Dan Garodnick, director of the Department of City Planning and the driving force behind the City of Yes rezonings. “It was the right time to take a hard look at zoning rules that were stifling businesses. Early results are in, and they are quite good.”

Meanwhile, office-to-residential conversions are gaining momentum. Originally concentrated downtown because of rules that only allowed conversions for older buildings along with incentives for neighborhood recovery after 9/11, landlords are now targeting Midtown office buildings, including in Times Square.

City of Yes now allows the conversion of any office building before 1991 in an area that allows residential use and exempts the building from almost all property taxes from 25 to 35 years as long as it sets aside a quarter of the units at below market rents. Other city programs have made it easier as well.

REBNY originally estimated that conversions would produce 20 million square feet and 20,000 new apartments. It now believes the figure could reach 40 million square feet and 40,000 units.

The most well known is the revamp of the former Pfizer headquarters on East 42nd Street, where Metro Loft is going to create 1,600 new units in what is being hailed as the largest office conversion in the world.

A few blocks to the north, Rudin is working on the overhaul of two of its office buildings at 845 Third Ave. and 355 Lexington Ave., which are not very far from its headquarters at 345 Park Ave. filled with prestigious tenants like the financial giant Blackstone and the NFL.

“We saw that tenants wanted to come to 345 Park Avenue and a block or two away there was no demand for office space,” said Bill Rudin, co-executive chair of the firm.

The first conversion expected to come online next year is actually the most surprising: 5 Times Square, built by RXR in 2002 as the headquarters of the ing firm EY. The firm decided to relocate to a new building on the far West Side in 2017. When the pandemic hit, RXR was able to ink only one small lease for the building and found very little interest in corporate tenants for Times Square, whose vacancy rate is higher than other Midtown districts.

But the building had been built in a way that made residential conversion much easier than other office buildings, and with changes to the zoning rules, RXR determined it could do an overhaul for a relatively modest price tag of several million dollars. It will create 1,250 new apartments, a quarter of which will be below market rate, that target a younger demographic.

“There will be studios and one-bedrooms that appeal to young professionals coming to the city,” said Jeff Holmes, senior vice president. “And the reality is we have a 1.4% vacancy rate.”

Developers are again seeking permits for new multi-family buildings, which dried up after the controversial 421-a tax break lapsed in June 2022 and wasn’t replaced by 485-x until this January. The new incentive provides a 35- or 40-year exemption from property taxes, which are so high for apartment buildings that few are ever built without a tax incentive.

In the first three months of the year, builders filed for almost 7,000 new units in 123 buildings, a 65% increase from the last three months of the year.

Meanwhile, in the first five months of the year developers who have to file an expression of an interest in using 485-x have indicated they are interested in building 2,600 units using the abatement.

But all those buildings are for less than 100 units, avoiding a requirement that any new building in the city must pay a minimum $40 an hour construction wage to access the tax break.

The city takes an optimistic view of the results.

“With 118 buildings representing roughly 2,600 new homes already showing intent to use to program in just 10 months of operation, 485-x is proving to be the tax incentive we needed to keep producing more affordable housing,” Adams said in a statement.

But the REBNY report noted that the 7,000 new units filed for in the first quarter is only a little more than half the 12,500 units needed each quarter to meet the mayor’s goal of 500,000 new housing units over a decade.

Real estate insiders suggest 485-x will work for large buildings where a rezoning allows a major increase in square footage. Scissura of the Building Congress said he expected an effort next year to revise 485-x if new construction continues to be concentrated in smaller buildings.

“Everything is playing out as expected. The absence of the larger projects we need at scale to meet the city’s production goals was identified early on by REBNY as a likely outcome of the new program design,” said Gerhards of REBNY.