THERE IS A lot that is offensive about the noisy labor protests that have become a fixture in Washington’s downtown business district. There is the raucous chanting accompanied by bucket-banging and whistle-blowing and the incessant clang of cowbells. There’s the cynical use of homeless people to do this dirty work. What’s most offensive, though, is the appropriation of the First Amendment as an excuse for District officials to do absolutely nothing to protect those who live and work in the city from unwelcome — even intolerable — noise.

An office building at 1101 15th St., across the street from The Post, was the latest victim of a union tactic that creates a public nuisance under the guise of protest. Picketers hired by the Mid-Atlantic Regional Council of Carpenters, a frequent practitioner of this annoyance, were targeting the use of non-union labor to hang drywall in the building. But as in other protests — most famously last winter’s picketing of the Madison Hotel — other businesses (yes, we admit to being irked) and people who live in the downtown area are affected. So loud are disturbances — which go on for hours, day after day — that offices as far as three blocks away from the target have complained.

Shaun Pharr of Washington’s Apartment and Office Building Association told us he’s at a loss to express “how frustrated” his members are because of the debilitating effects to businesses. Workers can’t concentrate, it’s impossible to meet with clients, and stores and services report a drop-off in business. Never mind the effects on those poor souls who moved downtown because they believed the city’s promise that it was a good place to make a home. When it comes to quality of life, they and the city’s daytime workforce are on their own.

“It is what it is,” D.C. Council member Jack Evans (D-Ward 2) told us when we asked why officials couldn’t find a solution to the problem. He said past attempts to tighten the noise ordinance have run afoul of the First Amendment. Baloney. Other cities have been able to enact reasonable noise control laws that protect the public peace while preserving the right to protest.

No one is suggesting that the union protests can’t continue, only that they proceed without the ruckus of bells, drums, whistles and other noisemakers. There is no constitutional right to annoy or disturb others, and no reasonable court would view bucket-banging and air horn-blasting to be public speaking.

If these protests are, as the union contends, “informational,” why was it that not one of the handful of picketers we attempted to talk to on 15th Street could explain what they were upset about or what issues were at stake? All they knew is that they were being paid by the hour to be as obnoxious as possible. These pickets are no more free speech than incessant car horn-honking. The refusal of city officials to enact reasonable protections is something that will give pause to firms thinking about moving into the District.