His aunt, who he has cared for over 16 years, was devastated by the news.
"I had cleaned the place all ready for her to come home. Now we have to work out where she is going to stay."
It was likely Mrs Sanger would remain in hospital for a few more days while a rental property or motel was organised, he said.
About $140 in cash had been taken from a money box.
"She puts away a bit of money to buy books," Mr Broad said.
Mr Broad said the house was insured but expected it could be some months before the house could be lived in.
Fire investigator Craig Bain said it was a heartbreaking case.
'This is a lady who has been sick and just wants to come home to her familiar surroundings and some dirtbags have come in and stolen her stuff and set fire to hide the evidence but it didn't work," he said.
"This tugs at the heartstrings."
Whangarei police appealed to anyone who may have seen any suspicious activity around the house late on Sunday or early yesterday.