"HABITAT," the United Nations Conference on Human Settlements held last year in Vancouver, was acclaimed at the time as a success. Almost inevitably, plans were made to institutionalize it on the theory that anything successful should and can be cast in permanent form. But it doesn't always work that way, of course, and the effort to find an organizational home for "Habitat" is floundering. There is no agreement on what part of the U.N. system, or on what city, to place it in. People argue about what it should do. Standby financial contributions have been few. Whether a permanent home for "Habitat" will be built is uncertain.

Well, so be it.We don't mean to be considered hostile to the problems of human settlements or indifferent to the United Nations itself. But there is no reason why every international consciousness-raising session has to spawn a permanent organization - though the temptation to do so in the name of "follow-up" has proven irresistible to at least three other U.N. conferences of the 1970s. Surely, the problems of settlements can be treated within the confines of existing development and planning agencies.

Sen. Araham Ribicoff's Governmental Affairs Committee addressed the general topic last February. Its report stated: "The large number of international organizations engaged in similar or closely related activities threatens the continued effectiveness and efficiency of the system of international organizations." Amen. Ten of the 65 organizations surveyed by the committee had been created in the last 10 years. If the recent rate of proliferation continued, there would be 855 different organizations by the year 2000. The new State Department team is, cautiously, eyeing the problem. This is no time to make it worse.