Reagan National’s new $374 million, 230,000-square-foot commuter terminal and two new security checkpoints are rising from the ground on the north side of Terminal B/C.

Turner Construction Company began the work last year, as part of the Metropolitan Washington Airports Authority’s larger, $1 billion terminal redevelopment plan.

The new 14-gate terminal will replace Reagan National’s current use of shuttle buses to bring commuter-plane passengers to the tarmac through a single lower-level gate — the dreaded Gate 35X — in the main terminal. It will have proper passenger bridges from the terminal to the planes, as well as new retail and restaurant options.

The new terminal is now going vertical, with steel frames now being assembled. Much of the work on the new concourse, and on two new security checkpoint buildings, to date had been demolition of existing hangars and MWAA office space, and pouring new foundations.

More than 240,000 square feet of new pavement has also been poured, which will serve as gate areas for regional aircraft parking at the concourse.

Once the steel structures are completed, installation of flooring and exterior glass will follow.

The new terminal is scheduled to open in 2021.