A police spokesperson confirmed officers had attended a "grievous assault". One man was arrested, and they weren't seeking anyone else.
A St John spokesman said a man was taken to Wellington Hospital in serious condition. He is now being treated for moderate injuries.
Naerby resident Gordon Mygind said he looked out his window to see a heavy police presence and a blood-soaked towel on the lawn.
He said it "scared the wits" out of him.
He understood the same family had lived at the Housing New Zealand property for about 30 years.
Another neighbour, who asked not to be named, said it was "very scary" to come home to the heavy police presence blocking off the quiet cul-de-sac.