OVER THE YEARS, the amount of space the federal government requires has continually increased - despite an ever-dwindling amount of available vacant land. One measure of just how much territory in the District of Columbia the government accupies is the amount of office space it needs. As of now, the federal government owns more than 100 office buildings in town and leases office space in 128 structures owned by others, amounting to more than 37 million square feet of federal office space in the District. According to officials in the General Services Administration, the agency that handles the government's property, there's every indication that continued federal expansion will create a need for even more offices in the District over the next few years.

A recent story by staff reporter Paul Valentine provided a clear picture of just what the effect of the government's growth will be. The number of tax-exempt properties is increasing, according to Mr. Valentine's account, with only a third of the city's entire acreage able to be taxed. Federal and Districtproperty, steets and alleys, schools, hospitals and other tax-exempt institutions are nibbling away the remaining vacant land. The result of all this is simple: Residential and commercial property owners who are now paying taxes are forced to carry an ever-increasing load.

Although local and federal officials realize this situation discourages prospective property owners from locating in the District, they have no solution. In the past, the tendency has been for city officials to call for an increase in the federal payment - that "reimbursement" to the District for taxes lost and services provided. But a federal-payment increase isn't the answer, since it wouldn't correspond with the actual costs of running the city. A better approach would be for federal and local officials to agree that all future office space needed in town by the federal government would be leased rather than constructed by the government. That would keep taxable property on the local roster, while allowing for the normal function of government. A leasing policy could also assist the city to attract business - governmental and private - into specific areas of town, and could also encourage rental of the very structures city offficials want to preserve. What's more, a leasing policy would cost the federal government of office space in the District. As far as we can tell, neither federal nor local officials have taken a serious look at a District leasing policy for new federal offices. We think its about time they did.