“sustainable building materials”
This is a misnomer in any tropical climate like Hawaii. Especially with the amount of rain they receive on this side of the island.
Any house that you want to last has to be either built out of concrete with lots of rebar. Any wood in the roof framing needs to be pressure treated against bugs and rot. You need lots of rebar because you are building on an active volcano. There will be earthquakes.
The only sustainable wood are very expensive tropical hardwoods like Cumaru, IPE, Koa plus North American Western Red cedar and Redwood. These are all very expensive species and need to be imported into Hawaii by boat. So, you could build a house out of these species of wood, but it would be quite expensive. Unless there is a sawmill on the Big Island cutting some type of native tropical hardwood that is naturally rot resistant.
But the boat would need to be made out of sustainable materials too.