Mo’ money, mo’ problems.

Seems like it’s back to the drawing board for billionaire Russian steel magnate Roman Abramovich, whose $6 million plan to combine three townhouses at 11, 13 and 15 E. 75th St. into a palatial single-family mansion were turned down by the city’s Department of Buildings, records show. (Abramovich just one of the 1 percenters who’s trying to bring back the mega-mansion to New York City.)

Some have said the effort wasn’t in the cards to begin with, or at the very least, quite difficult to achieve. The three townhouses, which Abramovich snagged for a cool $78 million in separate purchases beginning in October 2014, are located in the thick of the Upper East Side Historic District. And that means wading through the city’s notoriously tough Landmarks Preservation Commission to get what he wants.

It’s not like Abramovich wasn’t warned that the approvals process could prove nightmarish.

“Of course, [Abramovich] could apply for an endless series of landmark approvals necessary to connect the three buildings, which with their varying floor, ceiling and window heights, would be not only a bureaucratic nightmare, but an architectural one,” an Observer report noted last year.

On the other hand, not all are skeptical of the property’s future. Stephen Wang, the architect of record for the DOB application, tells The Post that disapproval from the agency can be part of the overall development process. In this case, he claims it’s more an issue of paperwork.

“You get an objection list and we actively work to address each of the questions,” he says, adding this hitch will not significantly delay the proposed mansion.

An agency representative did not return our call seeking further information on the applications filed with the LPC. Abramovich could not be reached.

For now, it seems, he’ll have to stay put in his London mansion, which reports say he bought for roughly $140 million in 2011. At this home, Abramovich also sought a multimillion-dollar reno to replace its “miserable” swimming pool with staff quarters and an underground leisure complex, which would bring the pad from 16,000 to 20,000 square feet.

If approved, those New York City filings — which were submitted in early December — would have yielded a sprawling 18,225-square-foot expanse across a 55-foot-wide lot. The application called for a 6-foot front yard, a 30-foot yard in the rear. The five-story structure would also have had a pool in the cellar, according to the records.

No other information on the Upper East Side proposal is available.