A Twin Peaks property owner has appealed a San Francisco Planning Commission ruling that he must build an exact replica of the 1935 home designed by famed modernist Richard Neutra that previously occupied the site.

Last month the Planning Commission turned down an application by property owner Ross Johnston to build a 4,000-square-foot home at 49 Hopkins Ave. that would have replaced the house the Department of Building Inspection ruled was demolished illegally.

Instead, the commission ordered Johnston to build a copy of the original Largent House, one of five homes that Neutra designed in San Francisco. Johnston’s lawyer, Andrew Zacks, called the decision “invalid, bizarre, and illegal.”

In the appeal to the Board of Supervisors, Zacks argued that the Neutra house was long gone by the time Johnston bought the property in 2017 and that the Planning Commission had in 2015 approved a remodel and expansion to 3,700 square feet.

“The commission’s order that the owner rebuild an exact replica of the original 900-square-foot 1935 Neutra home — a home that wasn’t even on the site when his family purchased the property in 2017 — is absurd given permits previously approved by the S.F. Planning Department for a 3,700-square-foot single-family home,” Zacks said.

Zacks also argued that the original home had been erased by a 1969 fire and remodels in the 1970s and 1980s, which included the addition of an indoor swimming pool. In 2014, Planning Department staff ruled that the house was not a historic resource and bore no resemblance to Neutra’s original design.

The “historic preservation controversy regarding 49 Hopkins has been completely manufactured by the Planning Commission for political purposes with no regard to the facts or previously approved permits,” Zacks said.

The contractor who illegally razed portions of the previous structure that were supposed to be preserved did so for “life safety” reasons, Johnston’s attorneys have argued.

Planning Commissioner Dennis Richards, who came up with the idea of forcing the developer to build a replica, said that the commission never claimed that the destroyed house was historic. He said the move was aimed at speculators who buy modest homes only to knock them down illegally and replace them with much larger, more valuable houses.

The decision received international coverage and sparked a debate about whether forcing the property owner to build a replica of a historic structure was appropriate punishment to an illegal demolition.

“Good luck to him — he is within his right to appeal, but I don’t know what he thinks he is going to get out of it,” said Richards. “He is not going to get permission to build a 4,000-square-foot replacement structure. I would bet my house on it.”

Johnston testified at the Planning Commission that he planned to move his family of six into the Hopkins Avenue house, but contradicted that in a recent news interview on a local access TV program in which he said that he is raising his family in Florida and that he just does speculative real estate development in San Francisco. The video has since been taken down.

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com Twitter: @sfjkdineen