The man was in a moderate condition, he said.
"Given what he was allegedly attacked with he was lucky.''
Neighbours said they heard yelling and screaming coming from the house just after midday but had no idea what was going on.
"They were all yelling and screaming,'' said one woman who did not want to be named.
Several police cars, both marked and unmarked, were parked at the house when the Bay of Plenty Times arrived.
Police were seen interviewing a group of about 10 teenage boys.
When asked what had happened, the boys refused to talk about the incident, saying "snitches get stitches, bro''.
Police said one youth had been arrested and two others were being looked for in connection with the attack.
Detectives were investigating the assault.
If you have information about the attack phone Tauranga police on (07) 577 4300 or anonymously call Crimestoppers on 0800 555 111.