The conservative Republican chairman-to-be of the Senate banking committee said yesterday he will move early next year to repeal organized labor's cherished Davis-Bacon Act as it applies to wages and work rules in federal housing programs.

In essence, Davis-Bacon requires that union wages and work rules be observed in all federally supported construction projects. Builders and GOP members in Congress have traditionally opposed it, but it has been maintained at the insistence of organized labor and its Democratic allies.

Sen. Edwin (Jake) Garn (R-Utah), who is to become chairman of the Senate Banking, Housing and Urban Affairs Committee in the new Republican-controlled Senate in January, says he believes the requirements must be lifted to stimulate the lagging housing industry.

"Now, organized labor is going to scream to high heaven, but I think we may have the votes now," Garn said in a telephone interview.

President-elect Ronald Reagan, who had previously decried Davis-Bacon as a "needless burden on taxpayers," pledged last month not to seek repeal of the act. Campaigning for union votes in Ohio and attempting to dispel the image that he was antiunion, Reagan said he would seek to "tighten up the administration" of the law, not do away with it.

Garn, in the interview, also said he advocates:

Raising rents for new occupants of federally subsidized housing and changing eligibility requirements so that it is available only to the poor, and not to middle-income families, as it is sometimes now.

Legislation permitting new kinds of home mortgages to help the many young people unable to buy homes because of the large down payments and high monthly payments now required. One new arrangement, he suggested, might be the graduated payment mortgage in which monthly notes are low in the beginning and increase as income rises.

A general pruning of Department of Housing and Urban Development regulations, which he feels often throw needless roadblocks in the way of developers building federal housing and mayors attempting to administer programs in their cities.

Garn has long been opposed to the Davis-Bacon requirements but had been unable to make any headway in Democrat-controlled Congresses. Earlier this year he attempted to make a tiny inroad by lowering the requirement, he said, that there be 10 experienced workers (journeymen) for every trainee (apprentice) in a neighborhood program in New York in which residents fixed up their homes. The banking and housing committee would not allow even that change.

When the new Congress convenes in January, Garn said, one of his first priorities will be to eliminate Davis-Bacon from housing programs as a cost-saving measure to help get the housing industry back on its feet.

Garn and the current banking and housing committee chairman, Sen. William Proxmire (D-Wis.), had pushed for changes in rents and eligibility requirements for federally subsidized housing this year but they were blocked in the House. Subsidized housing tenants pay 25 percent of their income in rent. What the senators would like to do is raise that to 30 percent for new tenants. Currently also, families with annual incomes up to 80 percent of the median for their area -- $21,600 for a family of four in the Washington metropolitan area; $17,100 in Garn's Salt Lake City -- are eligible for federally aided housing. Proxmire and Garn would like to lower that to 65 percent of median income.

Both these proposals are aimed at cutting the fast-rising cost of these programs, now the fastest-growing of all federal forms of welfare.

"I feel that where you have limited money available for housing subsidies, that it should go to the poor," Garn said.

A former mayor of Salt Lake City, Garn said he had always been bothered by the voluminous and frequently changing regulations of HUD. He said he believed the rules often needlessly slowed developers from building new housing and often confronted mayors with the necessity of following national standards that do not make sense in their cities. Insulation standards for Salt Lake City where it is cold in the winter should be different for those in Arizona where it is warm year-round, he said.

"What I would like to do in these housing programs is to have more local determination," he said. "A uniform national formula doesn't fit in every place."

Though he spoke only in general terms, he said he also favors changes to give local governments far more discretion than they now have to tailor housing programs to their own needs and situations.

"There is too much uniformity out of Washington [now]," he said.

Garn said he hoped to talk to Reagan about reorganizing HUD, which he said he believed is sorely needed. He said he would also like to be consulted when Reagan chooses a new HUD secretary.

He said he felt strongly that it should be someone with the local government background and experience of the current HUD secretary. Moon Landrieu, who had been mayor of New Orleans. While not suggesting that Landrieu be reappointed, Garn said he believed that the Carter administration had thrown obstacles in Landrieu's way and that he believed Landrieu had done a good job.