The other day, we wrote about former Timberwolves' exec Tim Leiweke, who now heads AEG, the supersized arena management firm, and his desire to renovate Minneapolis' Target Center. AEG is the arena's manager.

One sexy element of Target Center's renovation plans has been an environmentally friendly green roof, which would become one of the nation's biggest tree-huggable tops and the largest in Minnesota at 113,000 square feet.

Eighteen months ago, when arena and city officials began discussing this, a price tag of about $2.2 million was assumed, or perhaps $400,000 more than a standard roof. Energy savings were expected to pay off the capital cost difference within about five years.

Wrong again.

A new design was unveiled last week by Kestrel Design Group, which has also designed the green roofs atop Minneapolis City Hall and the Central Library, to name a few.

The new cost? Through the roof, city, arena and Wolves officials privately told MinnPost today.

It appears as if the difference in costs between the standard one and the "garden" variety is nearly $4 million, not $400,000. This would shoot the costs sky high into the $5 million zone.

(The project manager from the city's Community Planning and Economic Development department didn't return calls today to provide the exact costs in recent bids. If and when she does, I will update.) 

This renovation will be on the city's dime.  It owns the arena. For now, it looks like it's back to the drawing board.

Correction

This item was corrected. To see a full correction, go here.

For a fuller response, go to this Community Voices article by Kristin Guild.