A condemned and garbage-filled duplex apartment building in Alexandria, offered by council member Nicholas A. Colasanto as a gift to the city's "needy elderly," would cost taxpayers up to $100,000 to make fit for human habitation, according to a city report.

When Colasanto offered the building to the city the weekend before the Democratic primary election last March, he estimated the total rehabilitation cost at $5,000. Colasanto was defeated in the primary, in which his refusal to fix up the property had become a major campaign issue.

The councilman has been using the building in apparent violation of the city zoning regulations, which since 1951 have limited the number of apartment units which can be put on certain pieces of land, the report states. The zoning code for his property permits no more than two units on the lots but Colasanto subdivided the building into four units without obtaining permits, according to

- Supplementary report.

Colasanto said yesterday he had obtained the permits in "1937 or 1938," and denied any wrongdoing.

If the council accepts his offer of the property at 311-313 E. Custis Ave., Colasanto will receive a sizeable tax write-off. The building is currently valued at $82,000 according to city records.

The council will consider the matter at its regular meeting Tuesday night.

"I think the city estimates [for rehabilitating the house] are astoundingly high," Colasanto, 74, said yesterday. "They want to make mansions out of these apartments, putting in all tile bathrooms, showers and things like that. But if the city council doesn't want it, they don't have to take it," he said.

Colasanto, widely seen as one of the last of the "old boy network" of politicians who have dominated the city for years, also criticized city manager Douglas Harman, who is a non-partisan appointee of the council, "the finest politician in the city. He was responsible for several defeats in the recent election, not just mine," Colasanto said, declining to elaborate.

Harmon could not be reached for comment.

Mayor Frank E. Mann, an independent, was defeated in the general election by former mayor Charles E. Beatley, who had appointed Harman in 1975 during a previous term of office.

A report prepared by city rehabilitation specialist Zeb C. Martin calls for the total reconstruction and finishing of the units. Martin's report contains 29 specific items, including, floors, ceilings, sidings, windows, doors, hardware kitchens, bathrooms, heaters and chimneys. Total cost for the work was estimated at $98,015.

Included in the report is a recommendation to "take down garage and remove all rubbish ($2,200)."

The rehabilitation report was based on a city inspection which found rotted sidings, "garage full of trash/debris," fallen ceilings, broken windows, chipped plaster and a "loose commode."

Colasanto attributed the damage to vandals.

Last October the building was condemned as "unfit for human habitation" by the city health department. Under city rules, condemned residences not improved within a set period of time are taken over by the city. Colasanto said he would fight such an action in court.

Colasanto, who had been seeking an unprecedented fifth term in office, often said in interviews that because he was "a wealthy man" he could devote his last years to serving the city. However, he was roundly criticized by residents of the Del Ray neighborhood, where the building is located for his refusal to fix up the property. CAPTION: Picture, Councilman Nicholas Colasanto offered this house as a gift to the city. It may cost $100,000 to repair. By Ellsworth Davis - The Washington Post