The addition of a convention center proposed by Brookfield officials as a way to boost the city's economy would generate about $275,000 in increased annual revenue for the city, a new report says.

A city study of the potential new 44,200-square-foot convention center near Brookfield Square mall or at the former Ruby Farms property at Calhoun Road has drawn interest by developers, said Tim Casey, Brookfield's economic development coordinator. The building could cost at least $21 million and would also generate nearly $350,000 in annual state sales taxes, according to a report.

"We have at least one developer interested and we have others who have inquired," Casey told the city's Economic Development Commission. One developer is interested in proposing a larger mixed-use project that could include a hotel and conference center, he said.

Based on interest by the Brookfield Convention & Visitors Bureau, the city jointly funded a feasibility study by a Chicago-based consultant HVS Convention, Sports & Entertainment. In a 121-page report released in October, HVS said building a medium-sized convention center would allow Brookfield to successfully compete for state and local association meetings local hotels can not currently accommodate.

HVS estimated a "high-end" Brookfield center could attract about 250 events and about 81,000 guests a year — but it would cost between $21.8 million and $30.2 million. With contingency, insurance, fees and other related costs, the total development costs could be around $27.2 million to $37.6 million.

On Monday, a second study was released, an economic impact analysis by Springsted Inc. of Milwaukee.

Springsted said by 2018 a center would generate $274,668 in increased annual property and room tax revenue for the city, plus $348,327 in state sales taxes.

Assumptions in the analysis included an increase in the city's room tax rate from the current 8 percent to 9.5 percent, an average nightly hotel rate of $125 and a $21 million building value.

Adding a conference center would generate about 13,200 new room nights to Brookfield's hotel market, which is the third largest cluster in the area, behind only downtown Milwaukee and the area around General Mitchell Airport.

Even the largest convention centers in Chicago and New Orleans only generate about 10 percent more hotel stays, said Casey and Nancy Justman, executive director of the Brookfield visitors' bureau.

"The conference center will generate some rooms, but it's more about the economic development," Justman said.