A Prince George's County Circuit Court jury ruled yesterday that General Motors Corp. must pay $1.5 million to a District Heights man who was paralyzed from the chest down in a 1975 traffic accident.

The jury accepted the contention of George E. Lahocki, a 24-year-old former plumber, that his massive injuries were caused by faulty construction of the 1971 GM Vandura van in which he was riding when the accident occured.

According to tesitmony to the six-week case, Lahocki was thrown from the vehicle when the van't roof came off as it struck a barricade on University Avenue near Metzerott Road. An engineering expert testified that the roof was held to the van's body by 60 welds, whereas the specifications for it called for 212 welds.

General Motors, represented by Baltimore attorney Edward Diggs, argued that Lehocki's injuries were not the result of the roof coming off. The company said it will appeal the judgment, which several lawyers said is one of the highest in county history.

The jury awarded $1.2 million to Lahocki directly and another $300,000 to Lahocki and his wife, Doris, who testified during the trial that "I have no future" because of the paralyzed condition of her husband.

"We knew we could win it, but we also knew we were up against No. 1," said Lahocki's attorney, Karl Feissner, after the jury's ruling on the civil suit. "They (GM) brought in all their troops, experts and movies. They try to wear you out. But we met them one-for-one."

Lahocki's suit also named as a defendant Contee Sand & Gravel Co. Inc., a construction firm that put up the 4-foot barricades the van struck, but the jury ruled that only General Motors was liable.

Lahocki was working for Warner Plumbing Co. during the summer of 1975.

On Aug. 25, he was riding home in a company van driven by his assistant, George H. Camphell, an old friend. Both men had consumed three beers before driving home, according to pretrial deposition accounts. As Camphell approached the Metzerott intersection with University Avenue, the accounts said, he and Lahocki noticed barricades on the street 300 feet ahead.

Camphell, traveling at 55 miles per hour, could not turn into the one lane that lacked barricades he said, because a blue sedan was keeping pace with him in that lane.

The van plowed into the barricades at nearly full speed. Camphell, who was wearing a seat belt, suffered minor injuries. Lahocki, sitting in a makeshift seat without seat belts, was thrown from the van.