Abstract: A building unit including upper and lower surfaces, and a plurality of side surfaces extending between the upper and lower surfaces defining a generally trapezoidal shape in plan view. The unit includes a first pair of the side surfaces, located on opposite sides of the unit and extending non-linearly and generally obliquely with respect to each other in plan view, where each side surface of the first pair has a midpoint bisecting it into two portions. The portions on each side of the midpoint are a 180° rotational image of the other portion about the midpoint. One side surface of the first pair is longer than the other, and the longer side surface includes a midsection of the same length and configuration as the other, shorter side surface. Each of the shorter and longer side surfaces interlocks with either the shorter or longer side surface of another like building unit.

Abstract: A building unit has a substantially planar base having an outer periphery including multiple mating sides. Each mating side has at least one “S”-connection, which includes at least one outwardly extending male mating section and at least one inwardly extending adjacent female section. On the base, there are multiple cobbles or raised regions separated by false joints. A first portion of the raised regions are positioned on the male mating sections, respectively and extend to positions proximate to the outer periphery of the base. A second portion of the raised regions are positioned adjacent the female mating sections, respectively and are set back from the outer periphery. Each side of one unit can mate with any side of another like unit. The arrangement results in a surface covering that lacks a discernible pattern.

Abstract: A landscaping block, patio block, wall block and/or retaining wall block having a multi-textured or patterned exposed surface that can be used in landscaping, retaining wall, and/or patio block systems utilizing a plurality of blocks with a multi-textured or patterned exposed surface. The blocks having the multi-textured or patterned exposed surface can be used in landscaping, retaining wall, and/or patio block systems having a first block type and a second block type. The multi-textured or patterned exposed surface blocks can be used in the construction of walls, fences, and patios to create a geometric design or pattern or a repeating geometric design or pattern in a visually exposed surface of the wall, fence and/or patio constructed.

Abstract: A permeable surface covering unit comprises a top surface and at least two pairs of irregularly shaped mating sides, one or more passageways extending downwardly from the top surface, and at least one under channel connected to the passageways for retaining liquid, such as storm water. The sides of the unit preferably define an irregular rotational tessellation element. The passageways may comprise gaps or side cavities between units and/or core cavities or other passageways within the unit. Optional undercuts may be provided in the core cavities. Pervious material plugs are cast into the cavities extending into the channel or undercut. Thereby the plug is locked into the cavity like a rivet and resists being dislodged by mechanical or hydraulic forces. A permeable surface embodiment comprises a combination of pervious and impervious units, wherein the ratio of permeable to impermeable units and resulting surface absorption rate may be adjusted.

Abstract: A connection surface that is disposed on at least a portion of a face of a structural unit comprises a first convex surface and a first concave surface arranged substantially along a first line. The shape of the first concave surface is complementary to the shape of the first convex surface. A second convex surface and a second concave surface are arranged substantially along a second line that is substantially parallel to the first line. The shape of the second concave surface is complementary to the shape of the second convex surface. The concave-convex order of the second line is reversed relative to the first line, such that the second convex surface corresponds with the first concave surface and the second concave surface corresponds with the first convex surface.

Abstract: An irregularly-shaped building unit includes a front surface, a rear surface opposite of the front surface, and an outer contour surface that extends generally perpendicularly from the front surface to the rear surface. The outer contour surface is irregularly shaped. A plurality of mating sides are disposed on the outer contour surface, where at least two mating sides intersect with a major axis, and at least two mating sides intersect with a minor axis. The major axis and the minor axis are generally perpendicular to each other. Each mating side is a centered rotation about the respective axis that the mating side intersects with.

Abstract: A surface covering unit includes at least one face comprised of at least one primary rotational tessellation element. The rotational tessellation element includes at least two pairs of sides, and the sides in each pair of sides have the same length and are images of one another. The sides of a first pair of sides extend from a first vertex and are rotationally spaced from each other, and the sides of a second pair of sides extend from a second vertex and are rotationally spaced from each other. The sides of the first and second pairs of sides have two or more straight line segments or complex curves, and are not a single straight line or a single curve. One pair of sides has a length different from the other pair of sides. The surface covering has a natural appearance such that a repeating pattern is not readily apparent.

Abstract: A surface covering comprises multiple units adapted to mate with one another and cover a surface. Each said unit comprises at least one primary rotational tessellation element that defines the sides of the unit, has an irregular configuration, includes a face having molded surface irregularities or variations therein, and has at least two pairs of irregularly shaped sides. Preferably, gaps of variable width are defined between visible edges of adjacent units in the surface covering. The surface covering has a natural appearance such that a repeating pattern is not readily apparent. A structural wall unit system is also provided.

Abstract: An irregularly-shaped building unit includes a front surface, a rear surface opposite of the front surface, and an outer contour surface that extends generally perpendicularly from the front surface to the rear surface. The outer contour surface is irregularly shaped. A plurality of mating sides are disposed on the outer contour surface, where at least two mating sides intersect with a major axis, and at least two mating sides intersect with a minor axis. The major axis and the minor axis are generally perpendicular to each other. Each mating side is a centered rotation about the respective axis that the mating side intersects with.

Abstract: An irregular, tessellated building unit comprises x primary elements, wherein x is an integer equal to or greater than 1. The primary element is a rotational tessellation having a plural pairs of sides extending in a generally radial direction from plural vertices, respectively. In each pair, the two sides are rotationally spaced by an angle that is divided evenly into 360 degrees. Preferably, all of the sides are irregularly shaped, but one or more sides could be wholly or partially straight. Optionally, spacers are provided on the sides of each unit. A wide variety of units may be constructed having different numbers and arrangements of primary elements. As all the units are combinations of primary elements, they readily mate with each other. A surface covering comprises a multiplicity of units assembled to form a continuous surface without overlap between units and without substantial gaps between units. A structure, such as a wall or column can be formed of building units of the invention.