Developer Mark Mulligan cleared another hurdle Wednesday night in his plans to buy the Gov. Wolf Building in Easton.

Mulligan plans to convert the former school house that had served as Northampton County’s human services building into a high-end apartment building.

Mulligan, who hopes to close on a $1.9 million deal to buy the building in April from the county, received final approval for his plans from the Easton Planning Commission.

No changes to the building’s elaborate exterior brickwork from the late 1800s are planned.

The building’s 55,000 square foot interior will be converted into 50 residential units with a total of 67 bedrooms.

Mulligan has said the work should be completed by the fall of 2015.

The Gov. Wolf Building is one of several major large investments Mulligan has made in Easton.

He owns the National Bank Building on Northampton Street and developed the Pomeroy’s building down the street.

He also has plans to redevelop the Simon Silk Mill on 13th Street.