The City Council yesterday approved cost-of-living pay increases of nearly 5 per cent for District of Columbia teachers - a bonus that police, firefighters and other city workers began receiving last October.

It was the Council's second vote on the increase for about 7,000 public school employees. An emergency bill passed by the Council for the same purpose in December was inadequate, Mayor Walter E. Washington said. He submitted the measure passed yesterday as permanent legislation.

In a letter to Council members last month, the mayor said emergency legislation does not allow payment of the increases unless funds already are appropriated. The estimated $6 million raise for teachers is part of a supplement to the city's fiscal year 1977 budget that is awaiting congressional approval. The increase will be retroactive to last Oct. 1.

Teachers' pay checks are not likely to reflect the 4.83 per cent increases until at least early May, according to Council staff members and Washington Teacher Union president William Simons. The measure passed yesterday must be signed by Mayor Washington and then undergo 30 legislative days' review in Congress.

Simons has accused the mayor of discriminating against teachers by failing to implement the December emergency measure. He said teachers have lost interest that the money could have earned in savings accounts, in addition to the higher taxes they will have to pay on the increases when they are received with retroactivity in a lump sum.

"Can the mayor selectively choose which laws he will enforce" Simons asked yesterday. "Will he withhold his own raise since he was (included in) the congressional pay raises?"

Teachers "are so used to getting raises late that we don't even plan on them," a 20-year veteran at Hine Junior High School said yesterday. "Most people just go on living until you actually see it on the pay check."

The Council also voted yesterday to extend for the fourth time an emergency 90-day measure to protect tenants from renovation work that makes their homes uninhabitable before they can vacate.

Designed to protect tenants from the effects of real estate speculation in the District, the measure outlaws practices such as a landlord's beginning major renovation after he has sent a notice to vacate, but before the tenant has moved.

The law, now pending before Congress in permanent from, prohibits any alterations that place the housing in violation of the city housing code for more than 24 hours.

In a separate action, the Council gave preliminary approval to a bill authorizing the mayor to set fees for services at city health clinics operated by the Department of Human Resources.

The bill lists specific services that will be provided free, such as tests for venereal disease and lead poisoning. It also calls for a fee schedule covering all other services in DHR's 23 health clinics and the outpatient unithat D.C. General Hospital. The uniform charges are expected to save the city about $3 million a year.