The investment has improved facilities for Interserve's Yorkshire base following a number of large project wins in the region.
These include the £43m Factory 2050 for the University of Sheffield which has now been completed and the £13m Kirkgate Market redevelopment which is currently underway.
Interserve has also started work on site at the University of Hull constructing the new £25m Allam Medical Building.
The flurry of work has led to the company creating 33 jobs in the region, including five apprenticeships over the past year.
John Gittins, divisional director at Interserve, said: "Our newly refurbished offices are a reflection of this success and we look forward to continuing to deliver first class projects for all our clients across the region.”
The new offices were officially opened by Richard Ellis, UK operations director for Interserve.