U.S.-headquartered Jacobs Engineering Group is to continue developing new and refurbished facilities Royal Australian Air Force.

The New Air Combat Capability facilities project is in preparation for the RAAF's introduction of F-35 Lightning II Joint Strike Fighters. Jacobs has been providing design services for facilities in Australia in the initial planning phase of the project since 2011.

Under the terms of the contract extension, Jacobs will provide detailed design, final design and construction support services at RAAF Base Williamtown in the State of New South Wales and schematic and detailed design at RAAF Base Tindal, Northern Territory.

Work at the two bases for the F-35s include new aircraft pavements, aircraft shelters, working and training accommodation, hangars and maintenance facilities.

"This (contract) extension represents recognition not only of Jacobs' in-depth knowledge and experience in design services, but also our longstanding, trusted relationship with (the Australian Department of) Defense," said Jacobs' Group Vice President Michael Shirley.

The contract extension was issued by Lend Lease Building Pty Limited, the managing contractor on the base project. The length of the contract extension and its value were not disclosed.