Carriage Hill Associates, a New York development firm, is almost finished with in the construction of a 150,000-square-foot speculative office building in North Charleston, a sister structure to the Verizon Wireless call center next door.

Workers are finishing the steel building frame and hope to complete the project by the end of the year. The structure at 2405 Mall Drive will feature three floors of offices over a ground floor of parking with 120 spaces.

Ample parking is key in the Charleston market, said general partner Carl Lizza Jr. He said there are few large, Class A office buildings where employees can park nearby and without paying steep prices.

The new brick and metal building is still in need of tenants. Rental rates are about $22 per square foot, and companies that rent more than 5,000 square feet can also buy the space. Lizza said he's talking with two potential occupants. One is looking for 75,000 square feet and the other for 20,000 square feet. Neither has signed an agreement.

Larger projects such as this have been in demand in North Charleston, said Chris Fraser, broker-in-charge at the commercial real estate company Grubb & Ellis/Barkley Fraser. Most office buildings in that area are smaller and aren't attractive to big companies that are looking to relocate to the area.

"It's offering a big opportunity for a large tenant or tenants that don't exist in our market right now," Fraser said. "Five and ten thousand square feet doesn't go a long way towards economic development, whereas a 150K does."

Holder Properties, the Atlanta-based development group behind the Ashley Overlook building on Leeds Avenue, recognized that opportunity when it opened the speculative, 104,000-square-foot office building in July 2006. That commercial metal building project is now 84 percent filled.