A 5-year-old boy who lives at the house was at school at the time and suffered no symptoms.
Two other family members, who were in Upper Hutt and Palmerston North, made their own ways to hospital, but neither were suffering symptoms.
Porirua senior fire station officer Owen Woodman said the house's occupants had bought four litres of paint which they used in one room five days ago.
The paint gave off "heinous fumes" when it was opened.
"He did notice it was quite pungent when he opened it, but he just thought, 'Oh well, that's the paint.' He applied it but they were uneasy with how it smelt afterwards and they moved out of the house on Sunday because of the pungent odour."
Fourteen firefighters from four trucks were called to the house, which remained cordoned off last night.
Public health officials and Porirua City Council environment and dangerous goods officials were also involved.
The house could not be lived in again until it had been decontaminated, Mr Woodman said.
"That, unfortunately, is borne by the owner ... it will have to be decontaminated by a specialist company."
Mr Woodman said the tin of paint, which was not a common brand, had been removed from the house and was being examined. He would not disclose the brand.
The event was relatively low-key, despite the turnout from emergency services.
"But it could have had serious consequences," he said.
