A fire has caused significant damage to a commercial and residential building in Dunedin

Firefighters were called to King Edward Street just before 9 last night after multiple calls about smoke coming from the building.

Fire and Emergency shift manager Lyn Crosson says the blaze started in the two storey residential part at the back and moved to the one storey commercial part at the front.

She says within the building there's been some structural collapse but the whole building hasn't collapsed in on itself.

Lyn Crosson says no one was inside at the time of the blaze.

A fire investigator is on the way.