One Angel Square won a Royal Institute of British Architects award with judges labelling it "highly competent and elegant".
The Northamptonshire County Council headquarters were among seven other buildings to win an East Midlands award the ceremony at The Engineering Building, University of Leicester, last night.
It will also be considered for a RIBA National Award on June 21.
"Angel Square responds to an ambitious brief to combine workforces from 12 separate properties in a single excellent headquarters building," said the judges.
"The project, however, goes beyond a spatial planning exercise and capitalizes on bringing together the 2000 strong workforce by creating a building that actively promotes collaborative working.
"This philosophy is clearly evident throughout all aspects of the design."
"One Angel Square demonstrates a highly competent and elegant approach that showcases innovation in the workplace environment."
Last week marked the passing of world-famous Northampton architect Will Alsop.
In 2013, Mr Alsop hit out at the plans for Northamptonshire County Council's new headquarters.
Speaking to the Chron at the time, he said: "They’re dull proposals, there’s no doubt about that.
"I teach architecture as well as practise it and if any of my students produced any of these designs I would have a serious word with them.”