Abstract: A construction-unit (23) that is adapted for being combined with one more similar units (23) to constitute a self-carrying structure (40) to use for shelter or dwelling wherein each construction-unit (23) make up for both one sidewall and half a roof in one segment. A plurality of construction-units (23) are adapted for constructing a static functional self-carrying structure (40) where the shape has a curved design related to the mathematical expression The Hyperbolic Cosine or part of an Ellipse in the traverse direction and a linear design in the longitudinal direction when placed as a part of an assembled shelter (40).