" I'm beside myself at the moment, I have no insurance."
The windows cracked from the heat and a plastic water storage container melted. Plants in her garden also partially caught alight.
"It just happens so quickly. The tin cladding saved my house from catching fire."
Ms Kerr said it was lucky no one was badly hurt, although the boarder did get burns to his hands and feet.
The boarder was taken to Tauranga Hospital for treatment and was discharged.
Unfortunately, a litter of kittens had not been found after the fire, Ms Kerr said.
"It was a bit sad because the mother cat couldn't get her kittens out. We couldn't get in there, it was too fierce and just scary."
The garage roof caved in and all the boarder's belongings were destroyed, including furniture and household goods, Ms Kerr said. Her deep freezer full of meat was also destroyed.
Maketu fire chief Shane Beech said he was called to the fire just after 4am yesterday. He said that on arrival the converted garage was fully involved.
"The occupant was out of the building and had burns to his hands and feet. Unfortunately, the building was totally destroyed by the fire but we managed to stop it spreading to the house."
Mr Beech said he believed the tin cladding on the house stopped it from catching fire.
The fire took more than two hours to put out as the roof caved in, making it harder for firefighters to get to the burning timber, he said. Mr Beech said a working smoke alarm would have given Ms Kerr's boarder earlier warning about the fire.
"It's all about working smoke alarms. He did the right thing by getting out of the building."