The complex will allow the existing intermational terminal to be converted into a domestic terminal to create a new 12mppa gateway by 2021.
According to Groupe ADP, which is carrying out the work through 100% owned subsidiary ADP Ingénierie, the project and other planned upgrades to the gateway are part of a vast reconstruction programme, resulting partly from the earthquake that ravaged the Nepalese capital in April 2015.
ADP assures that the new 95,000sqm terminal project will combine "modernity and respect" for Nepal's "all-encompassing natural environment".
In addition to the terminal, ADPI will be responsible for designing an adjoining VIP terminal; maintenance hangars for Nepal Airlines and the Nepalese Air Force; a new energy plant; and a storage facility for apron equipment.
Given the significant constraints of the site, which include an immediately adjacent forest and the steep slope of the land, ADP insists that all of its designs and technical features have considered the potential impact on the environmental.
It is also quick to note that the forest has not only been preserved, it has also been showcased through sensitive architectural landscaping.
Describing the new six contact stand terminal, Groupe ADP says: "The structure of the new international terminal is characterised by the soft curves of its roof, reminiscent of the silhouettes of the surrounding peaks.
"Also visible from inside the building, these roof panels complement the layout of the departures hall and the main work areas.
"Glass walls separate these two areas, generously casting natural light across the terminal’s interior.
"The terminal façades, also largely constructed using glass panes, will allow the opening up of the interior space to the beauty of the surrounding scenery.
"The interior design of the terminal meets the same environmental demands. This new terminal aspires to be an example for the region in terms of sustainable development."
According to ADP, the implementation of this huge project is the result of excellent co-operation with the local stakeholders.
The Nepalese authorities and ADP Ingénierie previously worked together in 2010 on a site survey mission and on the preparation of master plans.
As a result, says ADP, a team of ADP Ingénierie experts have worked closely with the Nepalese authorities on their traffic forecasts, the review of the 2020-2028 airport master plan and the fine-tuning of the development plan for all of the airport buildings.