Full-sized albizia house a model of innovation and

[terracore]

"Full-sized albizia house a model of innovation and sustainability at UH"

https://www.hawaii.edu/news/2018/04/22/f...zia-house/

I'll pass.

The wooden structure, which echoes the Waik#299;k#299; Shell or a Samoan fale, on the corner of University Avenue draws plenty of curious stares. A former doctoral student’s dream is now a full-sized reality near the School of Architecture at the University of Hawai#699;i at M#257;noa. Joey Valenti’s award winning idea to build an innovative temporary housing unit out of invasive albizia has come to fruition.

“I think it#699;s going to be a gamechanger for Hawai#699;i in a lot of ways,” says Valenti, now serving as project manager for the UH Office of Sustainability’s Albizia Project.

The prototype was constructed as a proof-of-concept of a single-family low-income shelter made from albizia, reconceptualizing the invasive species as a useful building material. It utilizes a design-build process that integrates state-of-the-art wood engineering technology and digital fabrication to pilot a Hawai#699;i-based system of sustainable wood structures.

In 2016, the UH president’s green project implementation $10,000 award from Johnson Controls kick-started funding for what was Valenti#699;s doctor of architecture project, a scale model home. Since then, the UH Office of Sustainability has raised about 10 times that amount to build the full-scale prototype, including funding from the Hawai#699;i Housing Finance Development Corporation.

“It’s a really great example of the type of integrated systems thinking that sustainability demands,” said UH System Sustainability Coordinator Matthew K. Lynch. “We’re excited about all the support we#699;ve gotten and all the excitement that the project has generated.”

The current albizia house has proven that the invasive tree could be used as a local building material. Future questions are economic feasibility and possible economies of scale. The goal is also to expand the project beyond albizia to other locally abundant species.

“We’re very cognizant of making sure we don’t create demand for an invasive species,” Lynch said. “We are thinking about this in a way that sort of mimics natural succession and evolution processes in nature. So if we can figure out how to create drivers for the removal, what then is the next step to replant, restore and repair our native ecosystems?”
House built out of Albizia wood might solve multiple sustainability issues

[Seeb]

It’s gonna cost $100,000 to build a low income tiny house. That thing is complicated

[ElysianWort]

Still think it's a good idea making use of the resources around oneself. Even if this initial try doesn't turn out successful.

[MarkP]

There is a fascination with log cabins as though they are somehow an elegant solution to something. They aren't. The joints between the logs are doomed to be very imperfect and to require heroic measures to seal them up. The wood expands and compresses across the grain with humidity changes and compresses over time, guaranteeing a lifetime of poorly fitting doors and windows. The walls are an average of solid wood (in some places) which does not have a great R-value, and caulked gaps in other places which has an even worse R-value. All this in a structure traditionally associated with cold climates. In reality the only reason that log cabins existed is that they could be built with only an axe. The original users of log cabins would cover them up with clapboards as soon as they could afford to do so.

Why all this talk of log cabins? The reference to a Samoan fale and the generally arched structure. This means that the design is being determined by aesthetic concerns rather than technical details just like the modern fad of retaining all the undesirable elements of frontier style technology under the mistaken impression that there is hidden value there rather than being the only structure you can put together before winter with nothing but an axe and a hand saw. People traditionally built in the old ways because they were dealing with the limits of the materials available to them as well as other technological challenges that we don't face today. A modern efficient design will only coincidentally look like a traditional design. How will sheet metal roofing be applied to this curved structure? It won't? Somebody is not serious about making the most efficient structure.

Also how does this meet code? Whenever the topic of alternative building comes up the issue of using lumber milled on site is touched upon. Generally speaking, can't get there from here due to codes. That sort of thing and proper disposal of sewage are the real deal breakers.

[terracore]

Mark you hit on all the key elements. It's a structure that only exists due to funding from a liberal college and is even labeled as temporary. Considering the amount of work that goes into the creation of a temporary structure FRAME (unless I missed it there is no photo of a finished structure with roof, walls, etc) it's not even a solution looking for a problem.... because there is nobody explaining that their problem is there are not enough uncompleted structures made of spongy wood that will rot before somebody finds a way to finish it.

It's a fine piece of art, but it's not a house, temporary or otherwise.

Hopefully I'm wrong but the only commercially viable use for this wood that I've seen is a replacement for Styrofoam in fiber glassed surfboards. And even then... not really commercially viable.

[MarkP]

I think that sells albizia a bit short terracore but it is definitely true that it is not a drop-in replacement for pressure treated Douglas Fir. I do wonder about the R-value of say 8" of solid albizia. I mean if the wood was almost free and properly milled and joined to avoid the drawbacks of crude log cabin construction (essentially old style single wall construction only with WAY thicker material) the result might be quite acceptable until the termites got to it.

[leilanidude]

Why not use the eucalyptus trees from Hamakua? There sure are plenty of them and I suspect that they make for a better finished product?

[kalakoa]

Why not use the eucalyptus trees from Hamakua?

Because they're feedstock for "green power".

[Rob Tucker]

Code does require "graded" lumber which means the lumber must meet a certain criteria for knots, checks, warp or other defects. Lumber generally has a lot of defects. #2 grade Douglas Fir framing material is minimal. Higher grades are required for specific structural uses. So Albezia would have to have a lumber grade criteria developed and this would involve its tensile and compressive abilities. Once that criteria is established you need a licensed lumber grader to do the grading. Training is generally four years.

I doubt Albezia would pass the testing.

[terracore]

"Because they're feedstock for "green power". "

Burning trees to produce power is carbon neutral because the CO2 released by burning the trees is equal to the CO2 scrubbed by the tree from the atmosphere while it was growing. As opposed to burning coal that releases CO2 from fossilized biomass that scrubbed a greater amount of CO2 from an ancient atmosphere when it was growing. In order for an energy source to be "green" it needs to have been carbon neutral while humans have been alive to observe it.

I am curious, they ship a lot of these eucalyptus trees from Hamakua to Asia. What are they doing with them?