NEW YORK -- One piece of the $46 million modernization of the home of the New York Army National Guard's historic Harlem Hell Fighters is being honored with New York City's premier award for historic preservation in construction projects.

The Lucy G. Moses Preservation Award, presented annually by the New York Landmarks Conservancy, "is not quite the Emmys or the Oscars, but in that community it is a very big deal," said Leonard Sherman, an associate with the architectural and engineering design firm of STV.

Sherman was the architect for the $2.2 million project to restore the main entrance façade along the Fifth Avenue side of the 83-year-old Art Deco-style Fifth Avenue Armory, also known as the Harlem Armory.

The project involved replacing 300 pieces of terra cotta, which decorated the face of the building, as well as reinforcing the underpinnings of the parapet wall. The most noticeable work involved replacing two five foot high Art Deco eagles decorating the corners of the entrance tower.

The Moses award, named after a New York philanthropist who died in 1990 at age 103, recognizes projects that demonstrate excellence in the restoration, preservation, or adaptive use of historic buildings.

Constructed in two parts -- a medieval-style drill hall finished in 1924, and the Art Deco administrative and office complex completed in 1933- the armory was built for the 369th Infantry Regiment.

The 369th was an African-American New York National Guard regiment that became famous during World War I for fighting with the French -- not the American -- Army.

The massive building, which overlooks the East River and Harlem River Drive, now houses the 369th Sustainment Brigade headquarters and its associated units.

Work on the armory began early in 2015. The goal is to move units back into the upgraded building in early 2017, according to Col. Scott Cleaveland, the New York National Guard's Construction and facilities management officer.

Along with upgrading the overall building interior and heating and ventilation system, the project includes installing a modern, state-of-art data/communication system. In addition the facility will have modern audio and visual equipment in select classrooms and administrative spaces.

The most visible evidence of the armory upgrade is the refurbishing of the armory's front entrance, which towers over the river.

The building was made a New York City landmark in 1985 and placed on the New York State and National Registers of historic places in 1994, so maintaining the look of the building was critical for the New York State Division of Military and Naval Affairs.

STV -- which provides engineering, architectural, planning and environmental and construction management services across the U.S. and Canada -- has extensive experience in making sure that historic New York City buildings look the same when upgrade and renovation work is done, Sherman said.

The firm looks for architectural drawings, construction records, and photographs for information on the structure and the original plan, Sherman explained.

Sometimes this "forensic" architectural study means going up on a scaffold and doing hands-on investigation into materials and construction methods used 70, or 80, or 100 years ago.

"It's one of the most joyful parts of the project," Sherman said.

In the case of the Harlem Armory, STV found reproductions of some of the original drawings and elevations, but no detailed information about the structure behind the building's façade, Sherman said.

Based on information garnered from the drawings and the firm's familiarity with buildings constructed in the 1930s, STV made some conservative assumptions about the type of structure concealed behind the parapet wall, he explained.

Unfortunately, when the workmen opened up the facade, they found solid, unreinforced brick masonry, supported by several corroded steel beams; not the steel framing as expected, Sherman said.

This involved changing plans on the fly, and coming up with a solution that resulted in reinforcing and repairing existing salvageable steel frames, introducing new steel framing and allowing for the introduction of waterproofing, he said.

"We came up with a system of welded galvanized steel plates and poured reinforced concrete, which provided a more substantial structural support and simplified the installation of waterproofing," Sherman said. "We believe that we have created a solution here that will prevent future water infiltration damage."

The company also found that a coating, which had been put on the terra cotta details of the building to prevent water from penetrating , had locked in moisture, damaging the architectural details, Sherman said.

Terra cotta is a clay-based ceramic -- a flower pot is one example -- that has been used to produce sculpture for thousands of years around the world.

The most impressive terra cotta details on the 5th Avenue side of the armory are the massive Art Deco federal eagles. Each consists of 13 large pieces of terra cotta.

Because the coating could not be removed without damaging the protective glaze on the terra cotta pieces, they had to be completely replaced, Sherman said.

Crafting replacement eagles and all other terra cotta fell to a western New York company called Boston Valley Terra Cotta in Orchard Park, which has manufactured ceramic products for over a century.

The firm specializes in terra cotta architectural details, said Patricia Herby, the firm's sales and marketing coordinator. For the Harlem Armory eagles, the company had to replicate the specific texture and glaze.

"It is really a balancing act between recreating the pieces so they are going to be viable for hundreds of years as well as preserving the history and the craft, the original look of the pieces," Herby explained.

The firm's craftsmen used the two original eagles to guide them as they reproduced all 13 pieces of each eagle 16 percent larger than the final product. That larger size takes into account the shrinking that occurs when the pieces are fired in a kiln, Herby said.

The glaze on the eagles also took research and extra work, she said. The final effect of the glaze is that of a burnish on the eagles, she said.

Planning for the 5th Avenue façade restoration began in September 2012 and construction finished, Jan. 2, 2015.

The next phase of the façade refurbishment will take place in 2018, Cleaveland said. That work will bring the 142nd St. and 143rd St. sides of the armory up to the same standard as the 5th Avenue side, he said.