Firefighters tackled the blaze in the commercial garage which involved a vehicle on fire. It is believed the fire started accidentally as a result of welding.
Wearing breathing apparatus firefighters used two 45mm jets and a high pressure hose reel to extinguish the blaze and cleared the smoke with a fan. Crews checked for hotspots using a thermal imaging camera.
Avon Fire & Rescue said the nursery was evacuated as a precaution.
No one was hurt.