If you want to fly a flag at half-staff for an occasion in San Francisco, it could cost up to $1,500. Local blogger and LGBT activist Michael Petrelis found that out the hard way when he asked The City’s Department of Public Works to do that in the Civic Center to commemorate the International Day Against Homophobia and Transphobia on May 17.

“I mean, c’mon,” Petrelis said. “If San Francisco, of all cities, can’t find a way to lower two flags for 24 hours to honor dead gay people from around the world, what does that say about San Francisco?”

Gloria Chan, a spokeswoman for Public Works, said union contracts require station engineers to lower the flags and be compensated at $90 per hour for a minimum of four hours, no matter how long the task actually takes. If the duty has to be performed at night or on the weekend, overtime payments are required.

For those of you keeping score at home, that could be up to $135 per hour for two four-hour sessions — one to lower the flags, and one to re-raise them — for a total of $1,080. What makes up the remaining cost is unclear.

Chan said Petrelis was provided with a fair, “across-the-board” cost for the activity, but considering the circumstances, the department plans to work with the inquiring group — Gays Without Borders — to lower the final bill.

Petrelis, who has raised the ire of some city officials in the past, noted that the Board of Supervisors unanimously approved a resolution in March to recognize the day. Chan said it remains unclear if Gays Without Borders would still have to cover the cost of the flag lowering in the case of a citywide recognition of the day, but that details are still being considered.

“We’re not here to gouge anybody,” Chan said. “We’re always willing to work with community groups.”

dschreiber@sfexaminer.com