Fire crews came back to Bundeena Tuesday morning after a fire reignited at a Baker Street house.
The house, near Eric Street, was destroyed.
NSW Fire and Rescue and Rural Fire Service crews arrived at 3.17am to the two-storey property which had its first fire at 3.30pm on Monday, April 27.
A man in his mid-30s was treated for minor burns to his lower legs and is still in St George Hospital, in a stable condition, after the first fire.
No one was home when the fire reignited.
Sutherland police said the two fires were not suspicious.
NSW Fire and Rescue crews from Bundeena, Sutherland and Engadine went to the scene on Monday and were assisted by Rural Fire Services from Maianbar and Bundeena.