Moshe Safdie's Coldspring in Baltimore is a fresh - a refreshingly fresh - approach to better housing at lower cost in economically, racially and ecologically balanced communities.

Safdie is the Israeli-born, Canadian architect who won fame at age 27 for his design of Habitat, the industrially produced "hill town" at "the Montreal world's fair of 1967.

Habitat, too, was to help solve the global housing problem by applying mass-production techniques and ingenious design to lower cost and raise livability at high densities. It remained a much admired, but expensive pilot project - a pilot flying stunts but never able to carry any passengers.

As yet, Coldspring, too, is abeautiful stunt.

The mass production system did not work. It proved less expensive to build Safdie's designs by hand, that is to say by conventional methods. THat is not the fault of Safdie's engineering, but the fate of pilot projects. No one wants to invest in the expensive machinery needed for mass production until there is a proven mass market.

The goal of economic and racial integration has been met for the first 40 families who are just now settling into the nearly completed first phase of the new town. Thanks to government subsidies, spacious two-bedroom houses with garden or terrace and loaded with amenities, range from $33,170 to $58,315 with a mortgage interest rate of 7 percent. Roughly a third of the residents are black. One third of the inexpensive houses are reserved for "moderate-income" families.

But the other two-thirds, middle-income familes, Safdie proudly told me, include six architects and Baltimore's housing commissioner. Like Habitat, Coldspring exudes urban chic. That may or may not help the cause.

Coldspring is located on 370 rolling, wooded acres, four miles northwest from the heart of downtown, along the Jones Falls Expressway. As planned over six years ago, the new town is to have 12,400 residents.

The first 40 families celebrated the opening of Coldspring the other evening with an outdoor dinner on one of the town's "decks," as Safdie calls his intimate little plaza.

It was a low-key event. With its low prices, Coldspring needs no publicity.

Besides, previous experiments with innovative housing, which were touted with great fanfare, collapsed in the face of technical and economic realities. Baltimore's remarkably progressive housing and redevelopment officials shy away from raising expectations.

Nevertheless, along with Safdie and the developer, F. D. Rich of Stamford, Conn., a number of Baltimore officials participated in what Jay B. Brodie, the city's housing commissioner, called "a happy neighborhood part."

Asked if he did not fear public criticism for buying a house that is heavily subsidized by his own agency Brodie laughed and said the thought had occurred to him.

"When these first units were under construction, I took my family to see them," Brodie said. "My wife and the kids insisted that we move here. At first, I thought that might be improper. But then some of my friends persuaded me that it might be a good idea for the housing commissioner to set an example - to show confidence, to demonstrate that this a good place to live."

Not everyone, to be sure, will want to live in what looks like a cozily huddling medieval town with all the modern conveniences.

Coldspring has density of 25 units per acre, which is 2 1/2 times higher than the density of a townhouse development and five times higher than your average suburban subdivision. Yet there is a garden for everyone.

Safdie thus is showing us an alternative to both urban sprawl and highrise buildings, which California architect Beverly Willis has rightly called "coffins in the sky."

To me, it is a delightful alternative. Safdie has created a picturesque townscape with constantly surprising bends and vistas as well as gentle grades that have both steps and ramps for baby carriages and wheel chairs.

The delight is achieved without phony additives, such as mullioned windows or stable lamps. In fact, all the houses are basically of the same design and the same materials - split-concrete blocks, stucco panels and bronze-colored aluminium. The variety is created with the arrangement of the units, some marvelous tricks - such as a housing unit placed across the street like a bridge - the flowers in the flower boxes, the things that people do with their gardens and their curtains and such. Safdie wants no architectural controls over individual taste.

The houses are basically the same for economy and the original hope of factory production. They are not individual units, but like Habitat, part of a megastructure - a comprehensive system.

The most important feature of this system is that it comes to terms with the inevitable implement of modern life - the automobile. Rather than letting it consume expensive land and get in our way, the plan integrates roads and parking. Cars are not allowed to mess up the neighborhood. They are parked underneath the houses.

The houses and their walkways and playgrounds are built on decks over the parking and service roads, which are on ground level. This means that you drive directly under your dwelling to park the car and walk up one flight to get inside, or two flights if you live in a two-family unit or maisonette.

"One of the things I am most proud of," Safdie told me, as we watched some children play in the cool shade of these decks, "is that I have the parking entrance pleasant."

The front entrance, the sunny playgrounds and the richly landscaped social spaces, such as the one on which the party was held, are, of course, on top of the deck structure.

The decks interlink with other clusters and, as the town grows, they will form a continuous network of walkways. "The walks will lead to the town cluster for which shops, restaurants, a hotel and office space are planned. In other parts of the town will be schools, libraries, community and recreation centers and all the other prerequisites of a small new town.

There are also plans for sunken high-rise apartments, so to speak - buildings rising to a height of 20 stories built on the bottom of a quarry, seeming to lean against the rock embankment. People will go down into their highrises. Down in the quarry, Safdie hopes to create a lake. It is all very romantic.

The romance is enchanced by one acre of open space for each acre of developed land. The open space is to be largely undisturbed woodland.

The romance is financed by a partnership between public and private enterprise. Federal money paid for the land and, via the city, for the infrastructure, as planners call it - the roads, sewers and those ingenious decks.

The Rich Company is both the contractor for the infrastructure and the developer of the town on top.

Ground has been broken for the second phase, but just how fast the town will develop neither Rich or Safdie ventures to predict. Public money is available to move right along. But much will depend on the market, on how people will take to Coldspring.

Like Safdie's Habitat, Coldspring, for all its appeal, might scare developers and housing officials with its novelty and remain just another option no one dares to develop further.

But it would be sad if this new option - this new approach to community design with better housing at lower cost - were again stifled by timidity and bureaucracy. It may help that the man who invited Safdie to Baltimore, former housing commissioner Robert C. Embry Jr., is now in charge of the federal urban development program.

Things are looking up for the city. But the very welcome rehabilitation of nice, old inner city houses for the well-to-do further aggravates the housing problem for the poor. The slums are stagnating in the backwash of the breakdown of "Operation Breaksthrough" (which was to bring us cheaper, mass-produced housing), of the Nixon moratorium on housing subsidies and the bankruptcy of the federal new communities program.

Coldspring, to be sure, is not directly available to the poor. But, by including moderate-income housing, it shows a way out of the ghettos. And it opens new vistas in the search for better housing for everyone.