"I cried for two hours. And there were rats," she shrieks, thinking back to their first days living in the houses. Five or so weeks on, and with a, well, almost liveable house, they are tired and missing their little fella, Otis, but their grand DIY design is on track and they are gunning for a win.
Now at least the house has a bathroom and a kitchen - a stark contrast to the dilapidated shell, with stinking damp carpet, gaping holes in the walls and crumbling brick work, that they moved into initially.
As Mark Richardson, the former cricketer turned comic sports broadcaster and now host of The Block NZ, says: "They were diabolical. Uninhabitable. There were lots of tears."
Inside the house, Tyson, a straight-up, stoic-type character compared to his bubbly and constantly smiling fiance, shows us round. The bathroom is dusty and dirty but finished, a kid's bedroom is also done and, not to give too much away, it comes complete with a spacies machine and some designer graffiti on the wardrobe door. Then he takes us into the first room that they completed - "our sanctuary" says Rachel - to show TimeOut how he barricaded the door shut at night to keep them safe from "intruders".
"It's hard living. They are creating the house around them," pipes up Richardson, who is taking us around the four, large sections located near the centre of Takapuna.
On The Block, based on Australia's most popular TV show, four couples have a starting budget of $100,000 and compete to renovate their homes and landscape the sections.
It's the most expensive non-drama series produced in New Zealand - though no one is letting on exactly how much the sponsorship-heavy show is costing, it's well into the millions.
TV3 and the show's producers, Eyeworks Television, are also protective of their talent, presumably for fear they might give too much away about how the competition unfolds. Turns out, they have good reason to be, because within minutes of meeting Rachel - bless her - she blurts out some vital information about one of the early episodes.
Of the other couples, Sarah and Richard - who already own a house in Hamilton - are not around today. They're out getting supplies from the building store but Richardson is more than happy to give his take on the couple.
"Apparently, they've never had a raised voice argument before and the first thing they do when something good or bad happens is they hug each other."
New Plymouth couple Ginny and Rhys - she's an intensive care nurse and he's an electrical linesman who gave up their jobs to be here - say a brief hello, but can't stop because they're off for more supplies too.
"She's a little firecracker. She's our eye candy. A show's got to have that," says Richardson. "She's pretty but boy can she turn, and you can tell if she's pissed off. And Rhys handles it really well, he's such a lad. But they are [also] a couple of down-to-earth, everyday New Zealanders."
And then there's siblings Libby and Ben who he describes as "an upwardly mobile brother and sister".
They're the "feisty ones", especially Libby, reckons Richardson. "She'll argue with you. [But] both of them have all the tools to be successful. They're driven. Competitive. In to win."
They're not at home when we take a wander through their house but as we emerge back into the lounge they are there to greet us.
"It's looking good," I say.
"Yeah, we've had a few doubters but they are coming round," says Libby, almost as if it's a dig at Richardson, which it probably is considering he admits to giving the contestants "jabs" to add a little spice to the show.
"I try to be positive. But I also try to jab them a little bit. You know, Ginny and Rhys with their lack of colour. But most of the time I'm more positive than negative," he smiles.
He believes the couples are a good mix, viewers at home will be able to relate to them, and most importantly, they are a solid bunch of people.
"They are put under so much pressure. And you don't want to be responsible for a break-up, but you also don't want people who will throw their hands up and walk off the show."
Given the multimillion-dollar budget, there's a lot riding on the show - and producer/director and reality show queen Julie Christie knows it.
"This is an enormously big deal for us, and to me personally which is why I'm back directing myself after 15 years and running round in the mud," she says.
One of the keys to making it successful was the long, intensive search for the right couples.
"It's a risky business," she says of the casting. More than 1000 couples applied, many were eliminated because of the trades they were in (builders, painters and interior designers were passed over), and among other things the passion of their applications and how they came across on TV were taken into account.
And she believes they've got the right lot. "It's 10 weeks, they live there, they breathe it, we have to look after them 24/7, and they're naughty, they use their power tools at night, a neighbour calls noise control, and we have to tell them off like school kids.
"But they are all devoting their lives to it. It's a hell of an emotional journey. You know, Ginny and Rhys had to give up their jobs. It really is life-changing for them."
Lowdown
What: The Block NZ, reality DIY show
Where & when: TV3, Wednesday and Thursday nights, 7.30pm
-TimeOut
