If you want to see a banker's blood run cold, just ask him if he's interested in helping to finance a project to build low- and moderate-income housing and retail facilities in a rundown and abandoned section of the inner city.

Usually, the answer is no. It's too risky a proposition, which helps to explain why developer and banker Jeffrey N. Cohen and community leaders couldn't get to first base in trying to borrow money to redevelop an economically depressed area of the Shaw neighborhood until the D.C. government recently agreed to step in with a commitment of up to $12.5 million.

In an unprecedented and complex deal, the city acquired the former Children's Hospital site and several nearby properties controlled by Cohen for $11 million and pledged to cover financing costs of up to $1.5 million.

A consortium of banks headed by the National Bank of Washington agreed to put up the short-term financing, provided the District paid them back and assumed the loan in a year.

The District hopes to recover its outlay in the long run from revenues generated by the redevelopment or from Cohen, who has personally guaranteed repayment of $6.2 million in three years if the plan flops. But first Cohen and the community group have to raise millions to make their plans a reality.

Mayor Marion Barry first demonstrated his commitment to revitalizing the area in 1982 by ordering the construction of a new municipal center on the northwest corner of 14th and U streets NW, in the heart of Shaw, an area ravaged by abandonment and street crime.

Construction of the municipal center is expected to have a ripple effect by encouraging development on nearby sites. Real estate experts say they already have noticed an upswing in Shaw-area land values, which may also be because of the plans to extend subway service to the area.

But Cohen's properties, some of which are only a block away from the new city office building, have not benefited. So his plans and those of his community partners are little more than broad generalizations and good intentions, with no financial feasibility studies.

At a news conference this week to announce the venture formally, city officials and the developers were vague about when construction would begin. They said they hoped refurbishing of the Lincoln Theater would start before the end of the year, with the redevelopment of the other sites occurring within five years.

The proposed redevelopment, called the Samuel C. Jackson Plaza, would include up to 1,000 units of low- and moderate-income housing and the renovation of the 1,200-seat Lincoln Theater and the old Manhattan Laundry on Florida Avenue NW.

In an era of diminished federal assistance for new housing, proposals for building large numbers of low- and moderate-income housing units in rundown neighborhoods are highly ambitious and risky. Moreover, the District's track record in producing redevelopment projects -- the disastrous Bates Street development immediately springs to mind -- has not been great.

Cohen, a close friend of Barry who is a godfather to the mayor's son Christopher, struggled for several years to redevelop some of the sites before he and the community group persuaded city officials to step in.

A Cohen partnership bought the old Children's Hospital site in 1981 in hopes of building a National Rehabilitation Hospital, but city health officials hampered that proposal. In 1983, Children's Hospital, which held a mortgage on the property, threatened to foreclose after a partnership including Cohen fell behind in mortgage payments by $500,000. That money later was paid.

Under the terms of the new agreement with the city, Cohen assumes some financial risk. But the deal has given him plenty of breathing room in which to put together development plans and relieves him of having to pay costs of owning undeveloped property, such as property taxes and mortgage payments. Most importantly, perhaps, the deal provided Cohen and his business holdings with $7 million to pay off liens and other debts against the Shaw-area property.

The city will hold a public hearing March 21 on the development plans for the area. City Council members and others interested parties would be well advised to ask some tough questions about the land deal and the development plans, before things go much further.