In all, Enron leases about 1.2 million sf at Four Allen Center; 575,000 sf at Three Allen Center; 27,759 sf at Two Allen Center; 59,448 sf at 500 Jefferson; and 42,558 sf at 600 Jefferson. The numbers add up to about 6% of the CBD's total 34 million sf, 57-building inventory and 8.2% of the downtown class A market consisting of 24.8 million sf.

Zigler was uncertain which of the five TrizecHahn buildings is being vacated, but the move was expected as the bankruptcy plays out. Just three months ago, Robert Kramp, Grubb & Ellis Co.'s regional director of client services, told GlobeSt.com that the office space at Three Allen Center was sure to be returned to its building owner along with that at 500 and 600 Jefferson. He predicted about 575,000 sf would be vacated in the Allen Center complex this year.

"The ugly confluence of a drastically downsized Enron and newly abundant construction will likely send downtown class A vacancy from the 3% level of the past year to nearly 15% by late 2002," Zigler concluded in a recent report, drawing on statistics collected in January and February. That call is in line with Kramp's prediction of 14% to 17% as a result of the Enron debacle.

Zigler reports Halliburton, Exxon Mobil and Shell are looking at the recently completed 1.2-million sf Enron Center South as possible homes. Some companies barred from the CBD because of two years of extremely tight class A space will use the availability to make their move. "In the long term," Zigler says, "downtown is still the place to be.