"The tiny house provides that opportunity."
It's something his parents were unsure they would ever see him do.
His mum, Lorraine Macmillan recalls a time while living on the West Coast when Christy would spend all day wrapped up in a duvet asleep, and at night would get up to watch videos.
"Once the house got quiet and the street got quiet, he would wake up."
Lorraine spent three years getting up and changing videos for Christy at night, until she went to a hospital appointment and saw a visiting locum doctor.
The doctor had a couple of "big files", with information about Christy, but he told Lorraine he would not read them.
"He said: 'you tell me what's going on'."
He was the first person to mention that Christy may be better living somewhere with people who are trained to care for them.
They decided to take him to Hohepa in Hawke's Bay, where they had lived as children.
Paul Macmillan, Christy's dad, had gone to school with the grandson of Hohepa's Hawke's Bay's founder, Lew Harris.
"Once we came up here, my husband, he came up to visit, and he said "well this is the place for Christy"."
At 13, he moved into a home in Poraiti. His improvement was dramatic.
Lorraine said his new tiny house was about teaching him to be part of a community.
Lorraine said while it was a big commitment for their family, they would build the tiny house a million times again.
The house was built by Francois Guittenit , owner of Le Workshop.
Guittenit said there were specific things about the house that made it easier for Christy, such as not having gas in the house and using an induction oven which he can not burn himself on.
Every window is safety glass, and the mezzanine level can lock off.
Stoodley said the model had the potential to be recreated in the future.
"This is obviously our first one, so we'll see how it goes, but obviously we think it's going to be successful or we never would even have ventured down this path."
A tiny house cannot weigh more than 3.5 tonnes, the biggest ones measuring 2.5m by 7.5m.