The landside sky bar and viewing platform will be located in what is currently the office space next to the security area.
The office space being created will consist of a new steel frame extension and replace the buffet restaurant area and offices, transforming it in a two-floor bar.
From Monday (20 December), the current viewing platform, drop-off point and short-stay car park are closing to the public so that work can begin. The drop-off/short-stay will temporarily move to the main car park.
Visitors to Fairs-Lloyds Travel and the Landside Cafe can still do so, and those customers will still receive two hours of free parking by obtaining a pass from the terminal.
The scheme of works will start in January with the removal of cladding from the terminal building and demolition of external walls by a former courtyard.
From February, the setting of foundations and the erection of the new steel frame extension and roof will begin. The viewing platform is due to be completed and opened by May.
Tees Valley mayor Ben Houchen said the latest work will see a "fantastic" new area created where people can "kick back, relax and enjoy the best views in the country" of aircraft taking off and landing.
"2022 will be the airport’s busiest summer in years, with Ryanair committed to the same popular destinations it brought to us this year," he added.
"It will also see the return of Tui, the world’s leading holiday company, after nine years, so people can be assured there’ll be plenty to see."
