A wealthy pair who spent years turning two Upper West Side townhouses into a mega-mansion — making enemies of their neighbors — have listed the lavish home for $85 million.

Paris-based businessman Pierre Bastid and his wife, jazz singer Malou Beauvoir, bought 48 and 50 W. 69th St., between Columbus Avenue and Central Park West, in Manhattan more than a decade ago for a combined $24.5 million — only to demolish both homes in 2018 and eventually build what neighbors have deemed an unwelcome monstrosity.

The roughly seven-year rebuild included significant excavation — much to the ire of locals who complained of the noise, dust, debris and toxic fumes from the site. Some even fled the neighborhood as a result of the pesky project.

Neighbors “awaken each morning to the jolting sounds and vibrations of jackhammers,” some residents wrote in a 2019 Change.org petition begging local officials to stop the project.

“We do not envision a megamansion or a swimming pool. Instead, we hear the steady digging of graves,” the locals fumed. “Figuratively and literally, we see our graveyards because of the various toxic fumes entering our homes and our bodies; as well as the death of our block, our street, and our neighborhood as we know it.”

The now nearly 20,000-square-foot home spans eight stories, including two underground levels and a 55-foot-long indoor lap pool that extends into the garden, listing agent Jim St. André of Compass recently told the Wall Street Journal.

If the property sells for its current listing price, it would be among the most expensive townhouses ever peddled in the Big Apple.

Bastid told the outlet that he had planned to make the mansion his primary residence but that “world and personal events” changed his plans.

He acknowledged that issues with neighbors have been “a major concern,” adding that his team had been in contact with local block associations.

“Once the foundation phase was over, the project team has remained in very good relations with neighbors,” he claimed.

But despite his assertion, neighbors continued to express fierce opposition to the project years into its construction, according to a 2021 article published on the local ilovetheupperwestside.com blog.

Three years into the project, residents shared their grievances on pieces of paper stuck to the physical construction site.

Photos of the complaints show they alleged “constant noise for years” and how the construction shook neighboring buildings and blocked the street to first responders and ambulances.

“The selfishness of these billionaires hurts my brain!” one person wrote. “Construction for years for TWO PEOPLE!!! Selfish, selfish.”

Given the harsh response from locals, “it would have been pretty awkward” for the couple if they had moved in, said Carol Xianxiao Liu, a lawyer who used to live in the area, to the Journal.

St. André declined to comment on the couple’s reason for selling, but a source told the outlet they had separated.

The current sales record for a city townhome was set in 2018 with the sale of the Wildenstein mansion on the Upper East Side for a stunning $90 million. The Wildenstein manse belonged to the art-dealing dynasty that once included Jocelyn Wildenstein, whose years of plastic surgery famously earned her the moniker “Catwoman.”