New business ideas typically aren't rewarded immediately. And office space in desirable downtown Charleston isn't free. But those two facts of life are getting some attention in a new venture by Charleston developer John Rivers.

Two months ago, Rivers and a group of local professionals teamed up to figure out what to do with an empty storefront in a commercial building he owns at East Bay and Charlotte streets. The 2,000-square-foot space was left vacant by a floral business that expanded in mid-2008 to Laurens Street.

The group settled on a catchy name – Spark Charleston – and a mission, which is to provide free, temporary business space for a handful of local entrepreneurs.

"This is what's come out of it," project spokesman Chris Clark said this week, as construction workers completed some last-minute details. The space, which will feature a clustering of desks and shared meeting space, could accommodate up to 14 people and open as early as June 1.

Spark Charleston is taking applications from entrepreneurs who want to occupy the space for up to six months. The process calls for, at minimum, a rough business plan with measurable goals. So far, Clark has gotten applications from companies involved in web design, real estate and finance.

"For now, the goal is altruistic," Clark said.

Despite the high cost of commercial real estate, downtown Charleston plays host to other so-called incubators, which typically offer cheap space to fledgling cash-starved businesses that need time to establish themselves before they to step out on their own.

For example, the S.C. Research Authority and the Medical University of South Carolina recently opened up incubator space aimed at medical research firms in a renovated mattress factory on upper Meeting Street. The city's Digital Corridor initiative has offered space in its "Flagship" headquarters at East Bay and Calhoun streets, and in a Rivers-owned building, for technology-focused startups.

"In order to help more people succeed, there's a need to create a support network, and part of that includes developing a physical infrastructure," said Ernest Andrade, director of the Digital Corridor. In some cases, the low-rent offerings have to be subsidized with public money to make the numbers work.