If you piled 1,000 cars on top of each other, you'd get some idea of the heft of all that structural steel that has been bolted and welded together in downtown Medford lately.

If you piled 1,000 cars on top of each other, you'd get some idea of the heft of all that structural steel that has been bolted and welded together in downtown Medford lately.

Work started last summer on two office complexes, one on West Main Street and the other on West Eighth Street, both with gigantic steel structures that have changed the skyline.

The four-story One West Main building at Main and Fir streets has 681 tons of structural steel but is surpassed by the 1,049 tons of steel going into a new Jackson County health building and its accompanying six-story parking garage off Ivy Street.

The two-story health building at Eighth and Ivy streets is 97,000 square feet and will cost $28.5 million, a price that includes the six-story parking structure. The buildings should be completed by September 2014.

The cost of the One West Main building is considerably less — $8.3 million — largely because the building owners are contracting out the interior work separately. One West Main also is being built around an existing parking structure.

Jackson County's health services building is designed to provide a more centralized and streamlined facility for health-care customers.

The parking garage was designed with safety in mind. Strange though it may seem, that's one of the reasons the steel beams have holes in them.

"It's fascinating to watch those steel beams being made," said David Wilkerson, a principal at Ogden Roemer Wilkerson Architecture, which designed the county buildings.

The design of the beams makes them stronger and lighter, and the holes will improve visibility by allowing more light into the parking structure.

"Security was a huge concern for us," Wilkerson said.

When finished, One West Main will house Pacific Retirement Service, Rogue Disposal and Recycling and Procare Software.

Pouring all that concrete — 2,208 tons for One West Main and 5,891 tons for the county project — in sub-freezing weather has been a challenge.

Steve Lawrence of Adroit Construction said propane heaters and special blankets are used to keep the concrete warm enough to set properly. Concrete is poured on each floor of the building.

Reach reporter Damian Mann at 541-776-4476 or dmann@mailtribune.com. Follow on Twitter at @reporterdm.