Benoit Brookens thought he was being overcharged for his air conditioner. Sylvia Gray got mad when she found an eviction notice tacked on her door after she had paid the rent.Kinnard Wright just saw the signs in the hallway. Mary Chione joined when some of the organizers of the rent-rollback cause were described to her by another tenant as "devils."

Thus the Dorchestr Rent Rollback movement began. Two years ago a group of tenants at the Dorchester House, a large, prestigious building at the crest of 16th and Euclid streets NW, started a series of petitions that has led the Rental Accommodations Office to decide that some of the tenants systematically have been over-charged and are due approximately $1.9 million. "This is the largest settlement by far in the city. And the whole proceedings have been more complex than cases I have seen in the State Department," Explained Brookens, an attorney, Dorchester tenant and former foreign service officer who has shepherded the case through dozens of motions and numerous setbacks.

Although court appeals are expected and distribution of the money is a while down the road, on Saturday about 70 people felt like celebrating. So they gathered on their yellow crepe paper-covered rooftop, with its breath-taking view sweeping from the Washington Cathedral, past all the monuments, church steeples, to the RFK, Stadium and the National Shrine, for further strategizing.

Call the mood of the day classaction ebulience. There were speeches and orders -- "Don't forget your rent refund and rent reduction forms, pick them up from the Wootens" -- reminders of the next meetings, emergency trips to apartment kitchens for more cups, oohing over the new babies, awe over one tenant who used a piece of gum to resuce some keys that had dropped into the floor slats, and a cheerful debate between two senior citizens about the quality of window cleaning.

One tenant was wearing a T-shirt that boasted, "I'm Ready for the 80s," and a lot of the lawn-chair talk was about a new mood toward grass-roots movements. "People are finally having the guts to stand up, that's the significant thing, the money is secondary. Times are really changing," said Gray, a training officer at C&P Telephone Co.

E. Carlton Mobley is one of the tenants who was sued by the landlord for underpayment of rent and has represented himself in some of the spinoff hearings. "Our success so far fortifies my belief people have to continue to struggle," said Mobley, the assistant dean of the Washington International College.

The group has an expansive supporter in Mayor Marion Barry who told them, "I commend you for hanging in, not giving up, not being pushed out . . . Don't get discouraged if everyone is not involved because great movements are started by a few people."

In September 1979, Brookens filed for rent overcharges for current and former tenants, covering the time between August 1970 and September 1979. The Dorchester's owners were also charged with refusing to sell the building to tenants who matched an $11-million offer from other purchasers that was later dropped. In July 1980, the RAO said the tenants had been overcharged since February 1973, when rent control was instituted, and that they were due refunds plus treble damages and 2.25 percent interest. Later, the RAO reduced the time frame to three years before the 1979 complaint. Earlier this year, the RAO said a plan for the refunds should be drawn up. After that is finalized, tenants say the move to buy the building will be regenerated.

Though the party was all smiles, cider and baked beans, some tensions between the Rollback tenants and other tenants still exists. In the elevator, one tenant reading a sign announcing the mayor's attendance at the Rollback party said, "You think the mayor is here? I think his time is more important than that."

But as Gil Scott Heron's voice echoed above the trees from the black liberation gathering in Malcolm X Park, Leamon Grier leaned back in a lawn chair and said the building's collective talent would overcome any clashes. "This is the thing for the future. This -- and it sounds funny coming from me -- but this is the basic American way."