The owners of a lower city property have pleaded guilty to altering a building in the St. Clair Avenue Heritage Conservation District without a heritage permit, the city announced Thursday.

A court found Luke Tran and Quy Hoang allowed the removal and replacement of some historic windows without a heritage permit at 712 Main St E., a historic house that's used for commercial purposes.

Planning staff started an investigation back in July 2014 and found that a number of windows in the building had been removed without a permit.

Designation under the heritage act allows municipalities to “recognize a property’s cultural heritage value and to conserve and manage the property,” the city says. A heritage permit is required for any alteration that is likely to affect a property’s heritage attributes.

“Designation does not restrict the use of a property or prohibit alterations and additions. Rather, designation ensures changes are appropriately managed for the long-term protection of significant cultural heritage resources,” said Steve Robichaud, the city’s director of planning, in a statement.

“There is no cost to the heritage permit process and staff endeavor to arrive at a satisfactory solution for each application; however, pre-consultation with staff is strongly encouraged to identify any issues prior to submission.”

The maximum fines for being found guilty of contravention of the act are $50,000 for individuals, $250,000 for corporations, and $1,000,000 for a total demolition.

The two men were slapped with a $1,500 fine each and given six months to pay it.