New security facilities and an enlarged departure lounge will feature in the overhaul, which is being launched today.
UK Transport Secretary Patrick McLoughlin is joining MAG chairman Mike Davies OBE and Stansted Airport MD Andrew Harrison to announce the project.
Harrison said the investment programme will radically improve Stansted to make it "the airport of choice in London for airlines and passengers alike".
"The way airlines and passengers use the airport has dramatically changed over recent years with far fewer passengers using check-in desks or travelling with hold baggage but spending more time in the departure lounge," he said.
"This exciting transformation project responds to these changing trends and will create a quicker and more efficient security process and bring some sparkle to what is already a fantastic terminal."
McLoughlin said the project will transform Stansted Airport’s terminal building and the way passengers use it.
"That’s not just good news for travellers. It’s also good news for the country because this sort of improvement to our infrastructure helps to make the UK more competitive."
The Manchester Airport Group (MAG), which recently took over the gateway, is investing $60 million in the project. Another $60 million will come from commercial partners.
The revamp will reflect how air travel has changed since the terminal opened in 1991, said MAG.
For example, the vast majority of passengers at the airport now check in online and over half travel without checked-in luggage, said the airport operator.
To improve the passenger experience, MAG has turned to psychologists to identify points in the airport where travellers feel confused, stressed and relaxed.
MAG is promising a more intuitive and easier journey through the airport, a bigger and relocated security area, double the amount of seating, better restaurants and more shopping choice alongside improved way-finding and additional flight information screens.
Elements in the overhaul include:
- A relocated and enlarged security search area, including 22 standard lanes and dedicated lanes for families, passengers with reduced mobility plus fast track for premium travellers to open in early 2014.
- Reconfigured landside/airside boundary to create a larger departure lounge and improved facilities including new and additional toilets, significant increase in flight information screens and new ‘calm zone’ between security and departure lounge.
- A complete redesign of departure lounge retail layout to provide more seating and space to relax, more bars and restaurants and a great choice of shops.
The development is part of a wider £230 million investment programme to upgrade security, retail and car parking services at Stansted over the next five years.