Despite considerable opposition from the D.C. Council, housing advocates and developers, the District's Zoning Commission recently approved a plan that requires developers to build some housing along with office buildings in downtown Washington.

Behind the commission's decision was the belief, shared by Terry Lynch of the Coalition for a Living Downtown {Close to Home, Dec. 16}, that downtown housing is essential if our city's core is to be active after office hours.

But office space generates the highest income in a city, so the land it occupies is also the most expensive in a city. To place housing on land that is zoned for offices means creating housing that only the affluent can afford. If an attempt is made to include moderate-income housing, subsidies become necessary, and fewer people benefit than if the same subsidies were used even a dozen blocks away -- a point made by Jim Dickerson of Manna Inc. {Close to Home, Dec. 16} in his argument for affordable neighborhood housing as opposed to luxury downtown housing.

One option to make downtown housing more feasible would be to downzone downtown land so that land prices fall to levels that allow affordable housing to be built. That, however, would be economically unwise -- Washington's main industry is office work, and without more offices in the future, we will certainly be worse off.

Another alternative is to allow exceptions to Washington's height limit -- one or two floors -- for the addition of housing units. Such a policy would increase the number of luxury units above office buildings, but unless such additions were strictly controled, our urban legacy would be at risk.

So what can we do?

Downtown housing advocates often point to European cities with their downtown residences as models of what American cities should be like, but it is too late to adopt that model for our cities, which have long embraced the concept of zones. Boston, which has as active a downtown as any city in the United States, offers us an alternative.

In Boston, few residences are mixed in with office buildings, but many people live in adjacent neighborhoods, like Beacon Hill, the Back Bay, the North End and the South End, which are just a short walk from the office and retail heart of the city.

Five days a week, Boston's office towers are full of people, and the streets below them swell at certain hours as restaurants cater to workers. The nearby retail center, Downtown Crossing (the equivalent of our F Street), is busy for a longer period -- and seven days a week. But both areas are quiet at night as activity shifts to the adjacent residential neighborhoods.

During these hours, the office core is indeed dead. But that doesn't mean Boston has a dead downtown, because the office core, made up mostly of skyscrapers, does not occupy a large area; its footprint on Boston's downtown is quite small.

On a more diffused scale, Washington resembles Boston. True neighborhoods -- Dupont Circle, Georgetown, Logan Circle, Capitol Hill, Foggy Bottom -- lie adjacent to the city's office core, just like in Boston. However, because of the height limit, this office core core has spread horizontally -- instead of vertically -- over many blocks.

If our goal is a more lively downtown after office hours, we should try to increase the amount and diversity of housing encircling the office district. We could transfer funds generated by a prosperous office district to create housing in adjacent areas (and throughout the city) and guard against the encroachment of the office core into the neighborhoods.

Advocates of downtown housing want a livelier downtown, but they seem to lack a full understanding of the factors that would make that possible. To require developers to include housing in areas zoned for offices will not serve their objectives. Yes, housing should be a public priority in our city, but not housing that overlooks Pennsylvania Avenue.

-- George Kousoulas is an architect.