Its turnaround in fortunes follows the appointment of Karl Goose as managing director two years ago and the start of its main works contracts on HS2.
Revenue increased last year by 19% to a record £456m due to the strong performance of its major live projects and the award of a £107m roads contract for Norwich Western Link project.
Pre-tax profit jumped to £5.3m from £1.5m in 2020 drawing a line under five previous consecutive years in the red.
The improvement saw operating margin rise from 0.3% to 1.2% as tunnelling work lifted performance at the business, which lifted headcount by a third to 584 staff.
Ferrovial Construction also maintained a healthy forward order book slightly down at £1bn with net cash up to £195m from £158m previously due to HS2 and the Silvertown Tunnel project in East London.
Goose said: “It’s excellent to see the result of the team’s hard work, confirming that we continue to head in the right direction despite the challenges of the pandemic.
“Infrastructure’s role in the UK’s economic recovery is clear and we are focused on sustainably contributing to this now and long into the future to support our clients, supply chain, and the communities where we work.
“Our growing and diverse team remains at the heart of our business and we will continue to prioritise their development, career progression and their health and wellbeing.”
He added: “Our early talent community will form 25% of our employee base by the end of 2022 with 62% of this year’s graduate intake from a Black or Asian background.
“Our focus for the year ahead will be to continue to bring innovation and excellent delivery to our clients and the sector, ensuring we hit our carbon reduction targets as approved by the Science-Based Targets initiative as we work with industry to achieve carbon neutral construction.”