Gas cylinders also exploded during the fire, which could be seen from Guernsey. The fire started at the property on Rue des Hamonnets, just north of Sion, at 7 pm.
A neighbour, who did not want to be named, said that the destroyed home – thought to be a Nissen hut – belonged to a man in his 70s who had lived there for years.
Firefighters spent two hours bringing the fire under control then spent the night damping it down. No one was injured in the fire, the cause of which is currently being investigated.