Local governments who "stick it to the new home buyer" - as Fairfax County, Montgomery County and others across the country do via high sewer and water tap fees, excessive subdivision development standards, and red tape - may be on the receiving end if a key official at the U.S. Department of Housing and Urban Development has his way.

William J. White, general manager of HUD's New Community Development Corp, and chairman of the Carter administration's task force on houing costs, calls local over-regulation "the most flagrant single factor" behind today's staggering new home prices.

Thousands of dollars per house are often "totally unnecessary" and could be pared off the simply would straighten out their tangled permit review procedures, relax their "unreasonable" standards regarding such things as interior sub-division roads, and get serious about reducing housing costs.

But White, who headed the Massachusetts Housing Finance Agency for eight years before coming to Washington last January, concedes that local governments aren't going to change their ways quickly - or perhaps ever without a push from the federal government.

Precisely how that push should be applied is under study by the Carter task force; the end result may be a lot tougher than some local governments imagine.

White believes that at a "minimum" his department should review and comment upon local building codes and subdivision regulations of communities participating in HUD-funded block grants and housing and planning programs. Since several thousand towns, countries and cities receive such funds yearly - including more than $3.5 billion a year in community development block grants alone -"this gives us a pretty good entry point" in tacking the problem, he said.

Using a code review procedure, White said, "we ought to be able to spot at least the very worst situations," and threaten to withhold funding to communities with regulations that needlessly add to housing costs.

HUD has legal authority, in Section 101 of the Housing Act of 1949, to conduct reviews and encourage "cost reductions through the use of appropriate new materials, techniques and methods . . . and the elimination of restrictive practices which unnecessarily increase housing costs,"White said.

The application of this statutory power, little used in recent years, to the highly popular block grant and housing programs created by the Housing and Community Development Act of 1974 is certain to be controversial.

picture Montgomery County's reaction, for example, if HUD said it faced disqualification for millions in block grants and housing subsidies because its subdivision rules were rife with overly restrictive practices that raise land development costs far beyond what they need be. Or picture Fairfax County's reaction to a resewer and water hook-up fees - which have jumped 195 per cent per new unit during the past seven years - in line wmay, if the task force recommends it, get specific new legislative language from Congress, empowering it to deny funds to communities which refuse to adopt cost-cutting model code standards for new housing.

If it wanted to, HUD could turn the stick into a carrot and provide positive incentives - bonuses in its own grant programs, housing subsidy and planning fund allocations - to communities that revise regulations that have been boosting housing costs.

The 42-member Carter task force of public and private experts, which holds its first full-dress meeting here early next month, has a growing list of ideas about how local governments can be persuaded to lessen their share of the housing cost problem, one way or the other.

The task force is virtually certain to come up with recommendations in its final report next year that will make officials in some jurisdictions squirm.