Conversation so far:
When did the renovations of Merchandise Mart take place
The Merchandise Mart was modernized in the late 1950s and 1960s.
What did the renovations of Merchandise Mart entail?
In 1962, a Merchandise Mart entrance canopy was constructed over the south for vehicle use.
How much did the renovations of Merchandise Mart cost?
A 10-year, $100 million Merchandise Mart modernization in the late 1980s included public utility upgrades.
Have there been any other recent renovations at Merchandise Mart?
Beyer Blinder Belle's commission in 1989 was to create additional perimeter entrances and restore the display windows, main entrance and lobby of Merchandise Mart

Question: What kind of expansions have they done?
Self-contained rewrite: What kind of expansions have been done at Merchandise Mart?