Robyn and David Shea with Grand Designs NZ host Chris Moller on the site of their Waiheke Island home.
Chris Moller couldn't believe his ears when Robin and David Shea told him their plans to build a "tree house" on Waiheke Island.
"We want to be in the bush. We want to be like a tree house," bridal designer Robyn Shea told Moller during the latest episode of Grand Designs.
"This is mad ... crazy," said Moller about Robyn's plans with her husband David, a commercial property manager, to build a bush retreat on the island, a two-hour car trip and half-hour ferry ride from their home in Tauranga.
Moller revealed their plans were on "a tricky site" with "major access issues" - including a steep 100-metre walk on a path that turned to mud during bad weather.
But Robyn and David had decided they needed a change from their suburban life in Tauranga, and forged ahead with a budget of $500,000 and time frame of six months.
Their design included a concrete path leading up to their home with two tower components, one with two guest rooms and the other with a garage and master bedroom, with a living space and deck sitting on top.
It was built to take in the island's sea views and designed to nestle into the bush, with contoured windows and roofing.
Things didn't quite stick to that plan, with a one in 500-year weather event dumping a month's worth of rain in one night on the island.
That flooded the house, caused multiple slips around the island and made the path up to their home virtually unusable. It also caused concerns the home's flooring could swell and need replacing.
"We should have thought of this when we bought the site," said Robyn. "We were in lovely, romantic, 'This is going to be amazing' mode."
Moller was also worried about the delays, questioning whether they'd taken on more than they could manage.
"Even when it's finished, it will never be a site that's easy to live on. I just hope when they move in the big compromise they've made on access will be worth it."
But by the end, he'd been won over - even when it was revealed the budget had escalated to $750,000 and building time had nearly doubled.
"I love the way house blends into the native bush," said Moller. "I love the way it twists and turns into the trees."
Robyn admitted they'd had a couple of moments thinking, "Oh my goodness, what are we doing?" along the way, but were proud of the results.
"Even just watching the trees in the wind, it's almost like they're dancing," she said.
"It's relaxing. Even in the wind, it's beautiful."
* Grand Designs screen on Three on Tuesday nights.