The Charleston City Market and San Francisco's Ferry Building have more in common than one might think.

They're both the focal point of their port city's respective Market streets, historic and iconic works of civic architecture.

And time has passed them by -- at least as far as their original intended use.

Far fewer people arrive in San Francisco by boat these days, while trucks and highways and grocery stores long ago reshaped the way we distribute food.

So saving these respective landmarks required some creativity and flexibility.

The renovation of San Francisco's Ferry Building was a preservation achievement of national importance, while the ongoing refurbishing of the City Market looks like it will be, too.

The most recent work at the City Market, the renovation of its largest and westernmost shed, posed the greatest challenge -- and resulted in the greatest positive change -- so far.

To help ensure its success, the design team visited the Ferry Building, the Redding Terminal Market in Philadelphia and other urban markets experiencing a resurgence, says architect Glenn Keyes, who worked with the City Market Preservation Trust, LLC.

The challenge of the western market shed was not simply its size, which is about as big as the market's three eastern sheds combined, but the desire of many vendors there to keep their spaces air-conditioned.

Air conditioning was introduced here in 1972 in a pretty awful way. This shed was a series of boxy (but air-conditioned) rooms linked by a dark, twisting inner corridor that blocked views. There were few chances to enter from either North or South Market streets, making it a sort of large retail intestine.

Keyes says the challenge was restoring the central path and linear view line from Meeting to East Bay streets, creating more attractive retail spaces more consistent with the rest of the market -- but also keeping them cool.

From Church Street, the design got rid of the imposing iron gates, which turned away some. "A lot of people thought it was closed," Keyes says. Also, there are new open-air spaces here to ensure a gentler transition to the air-conditioned space.

From Meeting Street, there also are new open-air spaces that do the same trick.

The shed's floor drops almost 4 feet from Meeting to Church streets, so maintaining handicapped accessibility also posed a challenge. That's why there are three gentle rises of 6 inches each on the easternmost walk. The rest of the interior gradually slopes up the other 2 feet and is 7 feet above sea level at its lowest point, just high enough to escape the Market's occasional flooding.

The most contemporary aspect of the design includes the large glass doors leading into the space. "We just wanted the clear lines," Keyes says.

The open bays, mix of uplighting and goose-neck lights, shelves and cross aisles is much the same as the changes made earlier to the three eastern sheds.

Also, a series of skylights were added along the ridge line to provide even more light. "We thought that was going to be controversial," Keyes says. "But because the pitch of the roof was so shallow, it was not such a huge visual issue."

Instead of the blank stucco panels between the masonry supports, Keyes designed a series of wooden doors. While they're inoperable, they have windows that let merchants advertise their wares to those passing along the street, adding more interest.

Awnings indicate the entrances and there are three places where people can cross through.

The columns are pockets that hide gates that vendors can wrap around their merchandise at day's end to keep it secure.

Vendors have spaces of only 150 square feet to 600 square feet, but those spaces don't feel cramped.

"The aisle essentially becomes part of your store," Keyes says. Vendors can move their merchandise about 2 feet into the center aisle.

All the merchants' signs were designed by graphic artist Gil Shuler and built by the same contractor to ensure continuity. Likewise, the cabinets and interior furniture were designed by Dan Sweeney of Stumphouse Architecture + Design and built by one contractor.

The renovation work also included some important civic service, including two new public restrooms and enclosed space for three large electrical transformers that will allow Market Street's telephone polls to come down by 2013.

Future work will improve the sidewalks alongside the sheds and perhaps even recreate the shed just east of East Bay -- the one that's been gone since the 1938 tornado --as a local farmer's market.

These changes all would further the City Market Preservation Trust's goal of luring residents -- not just tourists.

But those of us who live here should check out the change that's already arrived.

Robert Behre may be reached at 937-5771 or by fax at 937-5579. His email address is rbehre@postandcourier.com, and his mailing address is 134 Columbus St., Charleston, SC 29403.