"They must've known."
Sometime between 5pm on Saturday and 9am on Sunday when he went to open them, someone smashed through the back windows and ripped everything apart.
He said it was a heartbreaking thing to experience, especially so soon after holding his mother's funeral.
"You're just burying your mum and you walk in to someone ripping the place off.
"It's just a heart-wrenching thing."
Mr Porteous said so far they had only noticed a 107cm flatscreen TV missing but was expecting to notice more gone once the place had been cleaned up.
He said the outside shed had its door ripped off, too.
"Every single room in the house has been trashed."
"They've just gone through every single thing you can think of, they've even gone through the bed."
He had also heard about other burglaries happening in the suburb over the weekend and wondered if they were connected.
Rotorua police said they had received five reports of burglaries in the area over the weekend.