When Aaron Ackerman and his wife Jess bought a dilapidated property set on a steep hill in the jungle in the back of Palolo Valley, they knew it would take a lot of work to create what they envisioned. They didn’t know it would take nearly a decade to get it to where it is today.

You see, the catch is that Aaron, an architect and expert in sustainability at the firm Bowers & Kubota, was determined to build a house using the guidelines of the Living Building Challenge. Unlike being LEED-certified, which allows picking and choosing between criteria to collect “points” of sustainability, the Living Building Challenge outlines 20 extremely stringent requirements that must be met for certification— for example, all materials must be locally sourced, the house must produce its own energy and dispose of its own waste, etc.

In short, the property must have a net-positive impact on the environment. The construction, made from reclaimed redwood collected from demolished Oahu houses and draped with “curtains” of Pele’s hair, is a modernist treehouse fantasy. Their kids zip by in a giant cauldron set on a zip-line (used to haul construction materials and Costco grocery runs) or hang out in the netting splayed high up in the trees.

The house’s footprint meanders between existing trees they didn’t want to cut down, and inside, it is all wood and reclaimed-tile mosaic, the curved lines mimicking the natural forms of the world outside. Aaron hopes the house will soon achieve Living Building certification, which would make it the first residence in the state to do so.