Wall wants to replace the old and graying, though much-loved, Downtown Madison library with a structure that signals revival and growth while evoking optimism for the city 's future.

The Library Board should give the proposal strong consideration and, assuming the numbers work, open up the process to other bidders.

Downtown 's high-rise condo and office buildings testify to the city 's dynamic growth and economic diversity. The busy stores, cafes, restaurants, hotels and parks make the city a cool and exciting place to be.

Wall's design for a new library could be a public expression of this enthusiasm and confidence. But the project also has to be grounded in common sense, fiscal responsibility and optimal use of prime real estate. The design must remain flexible enough to accommodate changing technology.

The current library, which attracts nearly a half million visits a year, is bursting out of its 43-year-old, two-story, 90,000-square-foot facility. It has a leaky roof, rickety elevators and poor heating and air conditioning. It also is using very expensive space to perform back-office functions, which could easily be done in less costly quarters on the city 's outskirts.

The shoddy conditions are much to blame for a slight drop in usage at the Downtown facility. Throughout the entire Madison Public Library system, checkouts have increased 42 percent and visits 19 percent between 2001 and 2006.

Design and construction for a new library will cost at least $23.7 million, which the city does not have. Mayor Dave Cieslewicz has wisely refused to saddle city taxpayers with that expense.

Wall 's proposal for a glass and stone, nine-story structure to compliment the Overture Center across the street has a price tag of $43 million.

Downtown should have a modern, well-functioning library -- but not at any cost. What 's intriguing about Wall 's design is that it includes private office and retail space that could reduce the burden on taxpayers. The striking design, with a dramatic "hole " in the side of the structure that would serve as a green outdoor patio, also could help attract private donors.

The Library Board must carefully examine the financial details of Wall 's or any other developer 's proposal for this site in the 200 block of West Mifflin Street.

No matter what happens, Wall deserves credit for stepping up with a visionary plan for a stunning building that could give Downtown more oomph. It should encourage others to race to their drawing boards.

And it should push the city to drum up enthusiasm for a new library that would be a worthy and affordable addition to our growing city 's changing skyline.