In September 1991, the renaissance in affluent city living hadn’t yet picked up the momentum it would have a decade later, when a boom in condo- and mansion-building transformed large swaths of Chicago. That’s why one developer made the strategic decision to cut up a pair of derelict Gold Coast mansions into four residences.

The stone mansions at 1250 and 1254 North Lake Shore Drive “would be too big for most families these days,” I wrote in my first real-estate article for Chicago magazine, published 20 years ago this month. “1250 has roughly 10,700 square feet of space on its five levels, and 1254 encloses almost 9,000 square feet.” Each of the mansions had been built for a single family in 1891, but a century later, virtually anyone who lived grandly enough to need so much room would get a mansion in the suburbs.

Oh, how times and the city have changed. Eleven years after salvaging the mansions, the developer Art Frigo sold both units in 1254 to Jim and Eve Tyree, who would recombine them into one residence. (Jim Tyree was a Mesirow Financial executive who would go on to lead the 2009 rescue of the Sun-Times; he died in March.) And then in 2007, Frigo sold both units at 1250 (he’d been living in one of them). That buyer, Sam Mencoff, the co-CEO of Madison Dearborn Partners, has returned 1250 to single-family use. Frigo’s decision to divide the mansions in a way that kept their grand staircases intact looks prescient now.

Of course, the taste for super-sized homes isn’t only a city phenomenon. In 2006, I rounded up the three largest homes being built in the region. At 20,000 square feet, the city’s biggest dwarfed the Lake Shore Drive mansions. But the largest all around, a 40,000-square-footer in Burr Ridge, could swallow them both and still have an appetite for more.

Since that 1991 article on the Lake Shore Drive mansions, for a column that was merely called “Real Estate”—we started using “Deal Estate” in 2000—I have been to countless houses, condos, lofts, and even the occasional castle, monitoring the pulse of the local real-estate market. In 2000, when the boom was rising, we ran “The New Rules of Real Estate,” where I looked at how the breakneck speed of the residential marketplace was affecting the buying and selling of homes. In Chicago’s October 2011 issue, we present “The New New Rules of Real Estate,” the downhill follow-up, where I write about making peace with the painful financial losses most sellers have to accept these days.

With 20 years of reporting archived in my head, next week we’re launching a new series here called “DE Qs” (for Deal Estate Questions). Posting on Tuesdays, the weekly series will offer short videos where I answer readers’ queries about the Chicago-area real-estate market. The first, which posts September 20, discusses where first-time buyers can go to study up on the process.

Send me your questions, please! Are you wondering whether you should consider buying a foreclosed home? Which suburbs are often overlooked by first-time buyers? Which city neighborhoods have best held their value over the long term? Ask me. E-mail your questions to dennis@rodkin.com.  I’ll post one answer each Tuesday.

Thanks for reading these past 20 years.