Hempcrete is often called carbon-negative because hemp absorbs CO₂ while
growing, while concrete and steel — extremely durable — take significant energy to
manufacture.

Yes: Tierra Viva Construction, the Cal-Earth Institute, Earthbag Building
(Owen Geiger), The Mud Home and Build With Rise all work in earth-based and
alternative construction methods.

That’s the appeal: cutting waste from seaweed piling up on Caribbean
beaches while producing a lightweight, non-structural building material with
potential insulation benefits