When the curtain rises on next year's Spoleto Festival USA, a celebratory theme will be the reopening of Charleston's Dock Street Theatre.

Spoleto's spiritual home was closed two years ago for a $15 million makeover designed to strengthen its structure, improve its comforts and make its dressing rooms and other backstage spaces more useful — all while not messing up its unique historical ambiance.

"The theater will feel like the Dock Street Theatre," said Mayor Joe Riley, who paid frequent visits to the construction site. "You will go into the building and still feel the coziness and the warmth and the richness and the scale and all that."

The project, being done by NBM Construction Co. with design work by Evans & Schmidt Architects, is about 80 percent complete and is expected to wrap up by January.

Moments before this year's opening ceremony, Spoleto board members, staffers and other festival friends got a sneak peek inside and appeared to be quite impressed.

Jane Alexander, who performed inside as an actress before serving as director of the National Endowment for the Arts, joined dozens of people touring the building.

She later called it "truly astonishing. It is going to make everyone's spirits soar soon when it's finished. It made mine soar."

Outside, the Dock Street is beginning to look like its old self again, with its approximately three dozen brownstone blocks restacked on top of each other to create the six columns framing its Church Street doors.

These columns now consist of approximately 40 percent new stone, mined from the same Connecticut quarry as the originals, and they have inch-thick stainless steel inside them, providing reinforcement in the event of an earthquake.

Inside, the public areas of the theatre should seem very familiar — from the lobby to the theater itself. There will be larger restrooms to minimize lines, and the seats will be softer. The low balcony wall upstairs will be topped with a brass rail for added safety.

Also upstairs, a major change will be the expansion of the tap room, a small room next to the more ornate Wadsworth Room. Both can work together to host larger receptions.

While the city's original Dock Street Theatre was one of the very first in the nation, it burned down in the first half of the 18th century. The current theater wasn't created until the 1930s, when the Works Projects Administration built it from what was left of the Calder House hotel (later renamed Planter's Hotel) and a few neighboring homes built two centuries ago. Some of the building's more ornate trim was salvaged from a mansion that once stood at Meeting and George streets.

While a coat of new stucco originally covered the entire complex and gave it a uniform look, big chunks have flaked off over time, and throughout the 20th century, the city decided not to re-stucco it. Architect Joseph Schmidt said the current restoration essentially lets that continue.

"Every building was treated differently, as bricks were re-pointed or stucco repaired, to reflect when they were built," he said. "We figure in 100 years, it (the stucco) will all be gone," except on those buildings originally built to be stuccoed.

One complication of creating a theater from so many different buildings is that while the Dock Street has only three floors, it has seven levels. The current work adds three elevators to ensure that all of them are accessible to people in wheelchairs.

Much of the work, such as replacing the doors along Queen Street and reinstalling the new heating and air conditioning system, is designed acoustically.

Tom McGee of NBM Construction said all the hard work is done mostly by the same subcontractors who worked with NBM on the Market Hall and City Hall restorations.

Spoleto Festival General Director Nigel Redden said anyone who doesn't tour the building now won't be able to understand the scope of what has been done.

"This could have been done in a cosmetic way, but it's been done absolutely right. ... I don't think money has been wasted in any sense, but it's been done as thoroughly as any renovation could be done," he said. "I think this renovation will work for the next 80 years."