A rally set for this evening outside the saucer-roofed building that housed the just-closed Del Taco in midtown St. Louis is just part of the effort by some preservationists to save the architectural oddity.

Out today is a rendering showing how the structure, built in 1967 as a gas station, could be renovated and still retain its distinctive roof. The sketch is part of the effort to persuade developer Rick Yackey to find a new use for the Del Taco building instead of replacing it with a small strip center.

The image by designer Jon Hagar shows the building with its original storefront. Gone is the Del Taco drive-thru, replaced by an outdoor patio facing South Grand.

Architectural historian Lindsey Derrington says the renovation envisioned by Hagar would make the building pedestrian friendly and give it more interior space. Derrington says the added room would result in a building with nearly the amount of space Yackey says he needs to make a go of a new commercial development at the site.

As Derrington puts it, the Hagar-designed renovation would be larger than many successful bars, businesses, restaurants and banks in the city. And she adds, "It's even larger than most Starbucks!"

Tim Bryant covers real estate and construction for the http://www.stltoday.com/business">Post-Dispatch. He blogs on http://www.stltoday.com/businecolumns/building-blocks/">Building Blocks. Follow the Business section on Twitter http://twitter.com/postdispatchbiz">@postdispatchbiz.

Tim Bryant is a reporter for the St. Louis Post-Dispatch.