JAMES AND Marilyn Nollan had a small bungalow on their piece of beachfront property in Ventura, Calif. They wanted to tear it down and build a much more substantial house in its place, but this kind of construction requires a permit from the California Coastal Commission. The regulators were willing to grant the permit, but only on the condition that the Nollans allow the public an easement to walk along the beach across their property.

This may be a perfectly legitimate objective for the government to pursue, but, according to a Supreme Court majority the other day, it is not sufficiently connected to the granting of a building permit to avoid being a taking of personal property without compensation. Justice Scalia, who saw in the state's action an "out and out plan of extortion," wrote that the creation of a public easement along the entire coastline may well be "a good idea," but if the state wants such a right on private property, compensation must be paid.

This result sounds like a fairly straightforward, all-American proposition. The government's right to take private property has always been circumscribed, and even the imposition of conditions on the use of that property is not easily accomplished. Consider, though, the recent but now common practice of governments' conditioning zoning changes or large-scale development on the granting of certain concessions by the builder. Zoning boards frequently require developers to set aside parkland, to add low-income housing or, in urban areas such as New York City, to create plazas or pocket parks as a condition of building.

Courts could in the future find sufficient connection between these public purposes and the buildings to be put up, and allow these practices to continue. But four justices who dissented in the case fear that at the very least, developers will fight every such proposal in court. Justice Blackmun, for one, disagreed with the court's rigid correlation between the burden created by development and the conditions imposed by the state to ease that burden. Land-use problems, he wrote, require creative solutions, not an "eye for an eye" mentality.

Perhaps in the cases that are now sure to arise, courts will make distinctions between homeowners and large developers or between requests for building permits and requests for zoning changes. But for a while at least, both government planners and private property owners will be operating in an area of uncertainty where a great deal of money and the quality of life are at stake