"We could probably have scavenged a room and made it work, but the point is there is not enough housing to supply the demand and there are families on the street, even in Raglan. We also were conscious that if one house was to become free, we would have let it to a family."
They started building their new home in March out of a boat trailer, with a steel frame welded on it to become the skeleton.
With no labour costs, they completed it for $40,000 making the most of bargains and recycled materials.
The kitchen countertop is made of reclaimed 100-year-old rimu and matai that they restored. The joinery and windows are from the same place. The insulation was provided at no cost and, being a builder, Simon knew what directions to follow.
Most of the materials were sourced locally in Waihi, even though they could have saved "30 per cent of costs by going to larger stores in Tauranga".
"I am a huge believer of keeping the money in the community and we have spent so much money in the local stores and handyman places.
"We ended up being friends, some wanted to check out the tiny house," Simon said.
Despite the cost-efficiency of a small house, it is also the self-sufficiency aspect that seduced them.
Their house was built to be off the grid with solar-powered lights and compostable toilet.
Ona says that the number one "downer" for people to be off the grid is the sewage system and the solar energy. She says it is a game of "trials and errors".
"When you get the hang of this and look around, you will see how easy it is."
The motto of "minimising" was also appealing.
"I always found fighting myself not to be a consumer because we are programmed to purchase ... I am happy with very little but always found the urge to have more stuff. I had to catch myself to say, I can't have it and I should not, I don't need it because I can get by without it."
Tiny houses are becoming increasingly popular. In the United States, the 'Tiny-house movement' took its roots in San Francisco as soaring rents and home prices kept going up.
According to the 2017 survey from America's largest trade association, the National Association of Realtors, the size of homes for buyers (37-51 years) was 2100 square feet, and buyers of 36 years and younger and 71 years and older purchased homes at a median of 1800.
In San Francisco, space is a luxury, Ona said. Ona, who is American, has experienced it with Simon while living there four years ago.
"San Francisco's housing situation is really similar to what is happening in New Zealand. All of my flats were tiny, you get a small room to fit it all, everyone lives like this and they pay a fortune to do so. If you move there, you have to be prepared to leave all your big furniture behind and take the essential. It is a good mentality to practise."
San Francisco was also the place they both started to design and build their first tiny house.
Ona says she gained "50 million grey hairs" building their second house.
But seeing their friends' reactions at the housewarming was priceless.
"It was amazing. People were just so happy to be inside the house and were saying it feels quite spacious. At one point, we had 23 people inside," Simon said.
