At around 3.30pm, the digger was busy working at Bergluftweg (Mountain air way). For unknown reasons, the digger lost control and slipped on a hill, reported Blick newspaper.
The vehicle hurtled 15 metres down the slope and crashed into the wall of a family home.
The driver was injured in the accident and was brought to hospital. Luckily, no one in the house was affected.
Biel firemen arrived on the scene to bring the digger to safety. The extent of the damage to the property and the reason for the accident are still to be determined.
Biel, also officially known as Bienne, is the second biggest bilingual (German/French speaking) town in Switzerland after Bern.