Responding to the protests of tenant groups and D.C. City Council members, the D.C. housing department yesterday toughened emergency restrictions on developers who seek exemptions from the 90-day moratorium on condominium and cooperative conversions.

Yesterday's amendments increased the amount of money developers were required to have invested toward conversion in order to qualify for exemptions from the moratorium.

The regulations also were changed to allow only owners, and not contract purchasers, to obtain exemptions by proving they had serious plans to convert their projects before the Council imposed its moratorium on May 22.

The emergency moratorium passed by the Council was designed to provide some stability for the thousands of D.C. tenants who live in buildings where owners have received a permit to convert but have not yet begun to do so. Those restrictions will also temporarily halt the granting of any more such permits. They will not prevent conversion projects that are under way from being completed during the next 90 days, however, as the mayor was given the authority to provide numerous exemptions.

Last week, the housing department issued its regulations outlining exemptions. Those regulations included allowing any developer with a project of 20 or more units to apply for an exemption from the moratorium if he had invested more than $20,000 toward conversion. For projects with less than 20 units, the investment had to be more than $1,000 per unit.

But yesterday's amendments substantially changed that formula for projects with more than 30 units. Now, the developer of an conversion complex with between 31 and 50 units must have invested $30,000 or more in order to be exempt. For a building with from 51 to 80 units, the investment must be $40,000 or more, and for a project with more than 80 units, $50,000 or more.

A coalition of tenant group last week protested that the original regulations were "weak."

Mark Looney, a spokesman for the Emergency Committee to Save Rental Housing, said yesterday that his organization is "generally pleased" with the removal of the contract purchaser provision. "But we still feel that the dollar amount for substantial investment is too low," he added.

Looney said tenant representatives met with Ivanhoe Donaldson, Barry's assistant, last week after the regulatiions were released and an article about them appeared in the newspaper. "We urged him to amend them,' Looney said, "Ivanhoe told us last Thursday they would change the regulations."

Councilman David Clarke (D.Ward One), contending that the original regulations "far exceeded the law," also issued strong objections to several sections of the regulations in a letter to the mayor last week.

Clarke said he still isn't satisfied with the investment formula used, and added that he wanted other sections of the regulations changed as well.