The styrofoam hollow bricks known to date had various shape elements on their surfaces, but they were not the regularly repeated elements of the lateral walls, longitudinal and transversal, nor of the upper and lower walls, equipped with tongue and groove joints. This made it impossible to apply arbitrary mutual positions of the hollow bricks joined, both in one plane and in perpendicular planes, and clearly limited the variability of construction of structural building walls.

These inconveniences do not characterize the hollow bricks conform to the design here presented.

The styrofoam hollow bricks according to the present design have a modular structure with a horizontal module, preferably of 5 cm length, which consists in the repetition at definite distances of the same elements on each of the four surfaces of the wall of each brick. The upper and lower surfaces of the hollow bricks are equipped with the tongue and groove joints, linking upper horizontal walls of the underlying bricks with the bottom horizontal surfaces of the overlaying bricks.

Besides this, hollow bricks conform to the design are equipped with the modular height correcting devices, making it possible, in case irregular bricks are used in construction, like floor structure bricks, to bring up the height of the lower wall of the brick to the five-module height.

Each hollow brick has the height and width equal five module lengths, while the length of the hollow brick equals 20 to 40 modules. Inner walls of the hollow bricks are equipped with tee ledges, whose vertical axes of symmetry are distanced by one module length, while the styrofoam batten plates inside the brick have their symmetry planes distanced by five module lengths.

The elements of the tongue and groove joint, located on the upper horizontal walls of the underlying brick, have the shape of the ledges in the fonn of an elongated cuboid with the cross section of a square whose sides are equal 0.2 of the module, and whose edges are parallel to the lateral walls of the hollow brick, crossing the regularly distanced - by one module length - short anns having the cross section of a square, also having sides equal 0.2 of the module, and the edges perpendicular to the lateral walls of the hollow brick, while rabbets are located on the bottom walls of the overlaying brick, corresponding with their shape to the ledges on the horizontal walls of the underlying brick.

nle height correcting element is a complementary part whose shape is the one of a flat rectangle with the height of one module, width of five modules and length of 10 to 20 modules, and which is equipped with styrofoam batten plates of one module height, and on its upper and lower horizontal walls the elements of the tongue and groove joint are located, while the frontal walls of the correcting element have the thickness of 0.5 module.

The advantage of the hollow bricks conform to the present design is the capacity of joining them in any arbitrary place, corresponding to multiple module lengths.

Introduction of the height correcting element makes it possible to join bricks serving various purposes, like, for instance, floor bricks with the five-module bricks. This allows for introduction of definite variety into the structure of the building.

The subject of the design is presented in the exhibit, in which Fig.l shows the hollow brick in a lateral view, Fig.2 - the view from the top, Fig.3 - the view from below, and Fig.4 - the lateral view of the correcting element.

In accordance with the notations as in the figures the upper and lower horizontal surfaces of the hollow bricks are equipped with the corresponding ledges 1 and rabbets 2 fording the tongue and groove joint. The height and width of the hollow bricks are equal five modules M, while their lengths amount to 20 - 40 modules M.

The tee ledges (O, whose axes are distanced by one module M, are located on the inner vertical walls of the hollow bricks. The styrofoam batten plates 4 constituting the transversal walls inside the hollow brick, have symmetry axes distanced by five modules M.