"We have been looking for two months, put in tenancy applications for at least ten of those houses."
Even with a guarantor, Warman said because of her age, landlords were unwilling to let her sign.
"It's a difficult situation, I have to be an adult, but I don't have any rights to be an adult."
Under the Residential Tenancies Act anyone under 18 can legally sign a tenancy agreement as long as they are deemed to have a clear understanding of what they are entering into.
However, Warman said even though the couple had good references from their previous flats and had never missed a rental payment, no one seemed prepared to take the risk.
"Realistically we can afford $400 a week, even more if we have to. But we are struggling to find a place in our situation."
Warman met Johnson when she was 15 and had been with him ever since.
She first moved out of home at 16 and worked the night shift totalling 40 hours a week at a local factory in order to be able to pay rent.
Today she's studying full-time at Kelston Skills Update Training Institute, while her partner works for a company cleaning out sewage drains on average 50 to 60 hours a week.
"I've worked in a factory all my life, it's not a fun experience. I'm studying as I want to do something more with my life."
All Warman now wanted was somewhere safe to come home to at night.
She said going back home to their families was not an option for either. The teen was estranged from her family and Johnson's mother was unwell.
"My parents separated [and moved out of Auckland]. I couldn't move with them...we had a bit of a disagreement. [Going home], is not an option for me. I'm having a bit of space from family for the foreseeable future."
Ayleesha Gamble, 19, vouched for the couple's reliability when it came to rental payments. She had lived with the couple for almost six months, a year and a half ago.
"They were really good, they paid rent on time, always cleaned up after themselves. Kept everything tidy and were really great tenants."
Gamble sympathised with the couple's situation.
"I was in Brittney's shoes, no-one would let me rent their house because I wasn't 18."
She had spent two months living in a motel with her baby boy, while waiting for a house.
"I wasn't able to stay in the house that I was in, it was growing mould and I couldn't have my son living in the conditions."
Gamble said she was one of the lucky ones and has been given a home managed by Airedale Property Trust - the social housing arm of Lifewise.
A Ministry of Social Development spokesman said it was not uncommon for young people to find the "practicalities of starting out in life a challenge".
"Housing options can sometimes be limited and may involve staying with family or friends or sharing a house or flat with others."
The spokesman said the ministry had been in contact with the couple as recently as last week and would be happy to give them further guidance as required.
He said her partner was eligible to apply for social housing, but the fact the couple had pets was likely to limit the likelihood of success.
But Warman said the pets, two cats and a dog were family.
"They are like our children, they are not easy to get rid of."