Until now, the budget cutting fervor sweeping the country has been confined to talk. But yesterday the House Appropriations Committee began translating it into reduced federal services as it sent to the House floor a bill rescinding a -- wiping out -- $12.7 billion in spending authority for a wide variety of programs approved last year.

The largest single item was $5.2 billion that Congress has voted to spend over a period of years to provide subsidized housing for low-income families. If the rescission is approved by Congress, the government will add 210,000 federally aided housing units to the rolls this year, 44,550 fewer than previously planned.

The bill would also cut out $1.7 billion in grants to help communities build sewage treatment plants, more than $2.5 billion in various energy development programs, nearly $800 million in aid to education and more than $500 million in health and human service programs.

The total rescission was about $1.6 billion less than President Reagan had requested. (He has sought much larger spending reductions inthe budget for the next fiscal year, which begins Oct. 1). The bill is scheduled for action next week after the House votes on the budget resolution now being debated, which sets overall spending goals.

The bill also provides new spending authority for this year for unexpected needs of $19.1 billion. That is about $2.5 billion less than Reagan requested.The new spending items include $11.2 billion for defense, $1.2 billion for higher than-expected costs of the food stamp program and funds for other entitlements that cost more than previously budgeted.

The bill also would extend from June 5 to the end of the fiscal year Sept. 30 the stopgap spending authority that has kept in business departments such as Labor and Health and Human Services whose appropriations bills for this fiscal year failed to be enacted last year. The House committee included the anti-abortion language it taditionally has inserted in the HHS money bill, forbidding use of federal funds to perform abortions unless the mother's life is in danger.