A large boulder has smashed into a building in Christchurch after contractors dislodged it from a nearby hill.
The rock took out a fence and left vegetation strewn across a driveway before smashing a large hole into the Avoca Valley Rd garage about 4.45pm yesterday.
"It appears that contractors were up on the hill moving rocks and one has gone across the road and into the garage," police said.
No one was home and no one was injured.
Property owner Kevin Prince was contacted by a neighbour who told him of the damage.
He won't get to see the damage in person until the weekend.
"I was told they were blasting some rock, which is perfectly normal up there, and something went wrong and it got free and came down the slope.
"Obviously it is not what they expected," he said.
"I am just rather glad it hit my garage and didn't go into the house.
"It is just property. It could have been somewhat different."
Prince said the contractors had said they will cover the costs of the damage.
A section of the road was closed but reopened after Geo Tech gave the all clear.
WorkSafe has been advised.