Two terminals of the Des Moines International Airport in the US will be renovated under a $3m upgrade project that started in May 2009.

The renovated terminals will get new ceilings, walls, flooring, sprinkler systems and elevators to make them safer and more energy efficient, The Chicago Tribune reports.

In addition, the rest rooms will be refurnished and energy-efficient light bulbs will be installed at the new terminals.

The renovation budget will be collected from passengers by attaching a $4.5 fee to all tickets of air passengers travelling through Des Moines.