Firefighters were called to tackle a massive blaze at the former May Gurney office building in Trowse.
More than 19 crews attended the scene late at night on Saturday, where the fire had spread across the roof and first floor.
Videos captured from a property near the scene show the large emergency response and firefighters on aerial ladder platforms.
READ MORE: TUI passengers delayed at Norwich Airport for 10 HOURS with 'no announcements'
The site has been broken into on several occasions since becoming derelict and there have been concerns about security.
The site was earmarked for development in the East Norwich Masterplan and outline planning was approved in 2013.
But the works have proved controversial among people living in the area - with many raising concerns about traffic chaos and flooding.
This incident is being treated as suspected arson with enquiries currently ongoing.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here