An artificial reef structure is provided including various building components that are preformed from concrete and the like. The components include square blocks having recesses on the upper surfaces and male protrusions on the lower surfaces. The blocks can be matably interlocked by inserting the male protrusions into the female recesses of vertically adjacent blocks. Horizontally adjacent blocks are connected to each other using an adjustable double ring connector fitting within female recesses of adjacent blocks. The blocks allow seawater to flow through them using flow tubes that pass through the block and an interior chamber within the block. The artificial reef structure may be constructed to be positioned as a barrier adjacent to or in place of natural offshore reefs. The reef structure is preferably configured as a castle.

An insulation panel includes a first surface, a second surface opposite the first surface, a first side, a second side, a third side opposite the first side, and a fourth side opposite the second side. The first, second, third, and fourth sides define a perimeter of the panel. The insulation panel also includes a first conduit and a second conduit internal with respect to the first and second surfaces and extending between the first and third sides. The insulation panel further includes a third conduit and a fourth conduit internal with respect to the first and second surfaces and extending between the second and fourth sides. The conduits remove moisture that accumulates underneath the panel. Moreover, the insulation panel includes a slit extending from the perimeter to the first, second, third, and fourth conduits for discharging water accumulated within the insulation panel.

The modular construction blocks include a preform having a plurality of passageways therethrough. The preforms may by formed from a plastic material and filled with concrete and steel reinforcing bars to form footings, foundations, girders, walls, and roofs. The modular construction blocks generally include a 5-hole block which has five holes or passageways extending therethrough and a 2-hole block which has two holes or passageways extending therethrough. The 5-hole blocks include the plurality of passageways intersecting and extending along three different planes. Kits, building structures, furring strips, and methods for forming building structures are also disclosed.

A block (11) formed with a mold (10) integral thereto. The mold (10) is constructed as a mold top half (12) and a mold bottom half (14) and filled in situ with cement (16). The mold halves (12,14) are constructed with respective socket and channel structures (24, 20) to capture an enlarged end (38) of a connector (34) for interlocking one block to a neighboring block. The resulting block (11) constitutes a one-piece block that can be formed at the installation site using the two-part mold (10). The interlocked blocks are prevented from removal when moved in either lateral direction, or in the vertical direction.

Some embodiments of the present invention provide a spacer configured to mount a fan housing to a surface of a structural support. In some embodiments, the spacer includes a body, a first aperture passing through the body and having a first length through the body, and a second aperture passing through the body and having a second length through the body, wherein the second length is different than the first length. The body can be oriented in a first orientation with respect to the fan housing and structural support or in a second orientation with respect to the fan housing and structural support to mount the fan housing at different distances from a mounting surface of the structural support.