The crash happened at lunchtime and no construction workers were on the scaffold at Trinity House in Axminster.
Police confirmed that no-one was injured in the incident.
Eyewitness Christine Boyd told the BBC: “It’s extremely fortunate that no-one was working on the scaffolding or walking by as this is a busy corner for pedestrians visiting the town centre.
“One of the doors into the department store is located right beneath where the scaffolding was.”