Walls of Seaweed or Hemp?

We've decided on the komuten,the "carpenter/contractor," signed the architect's contract, and the basic plan is pretty far along. This idea of building a new house in the spot where our Taisho-era beach house has been standing for 80 years has taken on its own life, and I have no choice but to follow it.

Today was spent going over the plans at the komuten's office, but first visiting several of the houses they've built in the last few years to get a feel for various materials, mostly wood (cedar or pine?) for the flooring, and wall material (shikkui or keisodo). We went with the cedar for the softness and warmth under your feet, and the keisodo, which is supposed to absorb humidity. Shikkui is made of lime, hemp, and seaweed. Keisodo is made of seaweed, and earth. Both are biodegradable, and have their nuances but the keisodo's rougher texture seems better suited for the beachside.

Ike-chan, the just-out-of-architecture-school-but-hasn't-passed-his-architecture-exam assistant, had just finished the model of the house, and presented it to us with so much care and deference that, when he lifted the roof to show the inside and it fell to the floor and broke in half, we all stood and stared down at it, hands clasped before us, as if before an open coffin.

He did the ceiling of the tatami room and the beams in a wood-pattern, just like it will be. It shows clearly in this photo, but the model is so small you can just barely see the ceiling from the outside. It reminds me of Japanese chefs spending enormous time and energy cutting vegetables with great care and precision, knowing they're going to be dumped into a larger dish where no one will notice. I tell myself that I will peek into the tiny windows and look at this from time to time in appreciation.