A dovetailed building block includes a block body having a plurality of side surfaces. The side surfaces are constructed in an order of having a side surface with a dovetailed recess next to another surface with a dovetailed projection. The dovetailed projection of one said block body can engage the corresponding dovetailed recess of another said block body in a 90-degree cross manner. Thereupon, while in stacking a plurality of the block bodies, variety of secured and stable three-dimensional curved configuration can be built through angular engagement of one dovetailed projection of one block body and another dovetailed recess of another block body.

Construction materials intended for use as structural elements, such as structural blocks, used in the construction of buildings and civil engineering structures. The blocks can comprise hemp hurd and fibers, flax fiber, hydraulic lime and hydrated lime. In one aspect, the blocks may comprise a body shape configured so as to allow it to interlock with other blocks in the construction of a structure. In another aspect, the blocks may be adapted to incorporate tensioning means. Methods for manufacturing the blocks and structures comprising such materials and methods for building such structures are also disclosed.

A stackable block, comprising: a wall having an inner surface and an outer surface, the wall comprising a strip of material having a first end and a second end with a plurality of transverse fold lines spaced there between, the wall configured to define a structure having an upper perimeter and a lower perimeter, wherein the structure is formed by the strip being folded about the transverse fold lines and the first and second ends being connected together, and wherein at least a portion of the inner surface is vertically offset from the outer surface such that the upper and lower perimeter have stepped configurations.

An interlocking system of Emodular units engageable to form vertically and horizontally stable assemblies. The modular units include blocks and modular panels, each having vertical and optional horizontal bores that provide passage for plumbing, electrical wiring, and other connectivity. The modular units may be formed of lightweight cementitious materials, and may find use in assemblies such as walls, floors, ceilings, roofs, and entire building structures.