The Samuel Apartments are in such dire shape that the...

They couldn’t be more different, but there’s one thing that Manhattan’s chic Soho and Brooklyn’s hardscrabble Brownsville neighborhoods have in common — empty storefronts.

The two areas have nearly identical vacancy rates of around 13.5 percent along key retail corridors, a new Department of City Planning study into the problem has found.

And while lawmakers have pointed the finger at landlords for keeping storefronts empty as they hold out for higher rents, the study found burdensome regulations and shoddy planning — such as poor transit access, restrictive zoning and onerous parking requirements — are also to blame for the city-wide issue.

Brownsville’s subway-starved Pitkin Avenue retail corridor, roughly between Howard Avenue and Mother Gaston Boulevard, has a 13.4 percent storefront vacancy rate — compared with a healthy city neighborhood rate of 5 to 10 percent.

“There is an absence of major anchor stores to draw in shoppers, and a lack of subway access cuts the area off from potential customers in other neighborhoods,” the study said.

Those factors were coupled with a “lack of access to capital” and “negative perceptions of the neighborhood,” the study found.

Meanwhile, lower Manhattan is flush with deep-pocketed entrepreneurs and is consistently ranked among the city’s safest areas — but the area still suffers from a 13.8 percent vacancy rate.

Retailers there want smaller storefronts and are prevented from getting them due to onerous historic district rules, the report found.

“While the area is characterized by many large-footprint loft buildings, historic district regulations complicate subdivisions that could create smaller, easier to lease spaces,” the study said.

Nowhere is that issue more evident than along nearby Canal Street, where a whopping 25.9 percent of storefronts are collecting dust — the highest vacancy rate of the 24 commercial strips studied.

The long-vacant First National City Bank building on Canal Street and Broadway, for example, boasts 20,000 square feet of untapped commercial space — but only half may be used for retail under zoning rules, and “historic district regulations make it difficult to subdivide space,” per the study.

“All the stores have closed down,” said Jay Chin, manager of Canal Lighting, one of the few area shops still doing a brisk business on a recent Post visit to the strip. “Business used to be great in the ’80s, ’90s.”

Mayor Bill de Blasio pushed for a state “vacancy tax” earlier this year to punish landlords who reject reasonable offers and leave their storefronts empty waiting for higher-paying tenants,

But the study said the issue is as varied as the city.

“Vacancy rates are volatile, vary from neighborhood to neighborhood and street to street, and cannot be explained by any single factor,” the department wrote.

Additional reporting by Ruth Weissmann