The victim was taken to Palmerston North Hospital where he was scheduled to have surgery for non-life threatening injuries.
Police and the Armed Offenders Squad were called out last night but the gunman was not found.
Detective Senior Sergeant Simon Harrison said it was unclear if the incident was gang-related, but he confirmed the men knew each other.
"I want to reassure the public that police are committed to maintaining safe communities, and this was an isolated incident.''
The weapon has not been recovered but police believe it may have been a shotgun.
Investigators today completed a scene examination at the property and formally interviewed the victim and his father.
Police were still keen to speak to anyone who may have any information about the incident.
"We are continuing to interview witnesses and make area inquiries, and every effort is being made to locate the offender, whose identity is known to police,'' Mr Harrison said.
Anyone with information could call Palmerston North police (06) 351 3600 or Crimestoppers, anonymously, on 0800 555 111.