Charleston's grandest homes were built to accommodate many more people than today's average family of 2.6 people.

But even with that being the case, renovating one of them for two dozen boarding students, plus two residential advisers and their families - all while keeping the home's floor plan and historic integrity intact - is no small feat.

That's why Ashley Hall's recent work at 179 Rutledge Ave. stands out.

The imposing circa 1876 home has been remodeled as the school's Rutledge House for Global Studies, a sort of dormitory-classroom-student center for as many as 24 international boarding students Ashley Hall ceased having boarding students in 1974 but resumed a few years ago and now has 15.

Joseph Schmidt of Evans & Schmidt Architects and Fred Reinhard, the school's facilities director, helped oversee the project.

Their first job was to find a suitable property. They looked at one further south but found it didn't offer enough space. Even though 179 Rutledge was built on a triple lot and had 10,000 square feet, it almost was deemed too small as well.

But Schmidt figured much of the ground floor could be used for showers and bathrooms, which not only made that space productive but limited the amount of new pipes and wiring needed on the upper, more historically sensitive, floors.

"This is pretty much what saved the house," he says. "This could be converted back into a single-familiy home with virtually the same floorplan as it was before."

This extensive basement redo was possible even though immediately underneath are two 10,000-gallon cisterns, still working and full of water. "We did not destroy the cisterns," Reinhard says. "They are still relatively intact."

Schmidt says another advantage to the property was that it had only three owners before the school, and one of them didn't even finish it.

"There is a clash of styles and periods that is really neat," he says. Parts resemble an antebellum Italianate home, while some interior elements look very Victorian and eclectic.

It also is among the city's first homes built with an interior bathroom. "This had indoor plumbing laid in with the very first brick," Schmidt says.

But the 19th-century definition of suitable bathroom facilities is quite different from what code requires today. As with many historic home renovations, the greatest challenge is finding space to sensitively run new ductwork, pipes and electrical conduit.

The house had one cranny left vacant, and that also helped Schmidt figure out how to run new utilities to the upper floors. This cranny was an extra foot or two in the main parlor's northern wall that housed a pocket door. "That was our biggest gift," Schmidt says.

The grand first floor, used as a classroom and common area, still features its original mantels, chandeliers, plaster work, ceiling stenciling, shutters and more.

The second floor, which was less grand, contains four dormitory rooms, each of which can house six students and has a French door opening onto the piazza. The floor also contains a series of built-in closets and cabinets. One residential adviser lives on the third floor, while the other lives on the first in a renovated space of a former large kitchen.

The house meets modern codes, including a sensitively introduced sprinkler system, and even a separate bedroom on the third floor for sick students.

It also has a few other oddities left intact, including a raised section of basement with a slim, horizontal series of windows where its ceiling meets the nonraised ceiling, as well as a slim third floor dormer window. And its third floor is unusually spacious because it has a parapet-like section supporting the gabled roof, which is reinforced with steel pieces to prevent stress from bowing out the wall.

Even though 179 Rutledge was constructed during Charleston's post-Civil War doldrums, the city's inventory considers it "exceptional," the highest ranking there is.

Its construction spanned 11 years, as wealthy hat merchant Edmonds Brown began work in 1876 on a three-story black cypress home, though his plans later changed. In December 1886, he offered the unfinished brick home for sale, presumably because his Hayne Street hat business had been decimated by the earthquake earlier that year.

Architects Abrahams & Seyle designed it, making it one of the city's relatively few grand homes whose architectural paternity is known.

George Wagener, whose family had one of the South's largest wholesale grocery businesses, bought the home in 1876 for $13,762 and finished it a year later.

This fall, it begins another new chapter, still looking much like it always has.

Reach Robert Behre at 937-5771.