Concrete Masonry Units or CMUs exploded onto the building scene in the late 19th century with a flurry of different patents for block designs and production. While these concrete block walls have excellent fire resistance, sound insulation, and durability, their assembly is slow, tedious and expensive compared to other building methods.

The disadvantages of CMU block walls coupled with rising material costs and labor shortages have led to their waning popularity in recent years. Companies around the world have come up with exciting new alternatives to CMUs. Interlocking and stackable LEGO-style blocks make it easier to construct a wall and even build a home yourself. In this article, we’re going to explore 5 of these alternative building blocks. 

#1 – Polycare

The first innovative building block system is Polycare. 90% of their block is a filler of natural sands and the remaining 10% is a liquid binder which fuses the sand together. The mixture is compressed in a mold to form an eco-friendly geopolymer concrete block. The blocks are 5 times stronger than traditional concrete, while using a remarkable 75% less material. The block is 20 cm in width but the stone itself has a lightweight design. The two outer sides of the blocks are only 1 cm thick and the rest of the block is filled with insulating material. 

The assembly and construction process is as innovative as the blocks themselves. The foundation is made of base strips into which threaded rods are screwed. Polycare blocks are laid over the threaded rods and stacked vertically to form walls. The interlocking design eliminates the need for glue or mortar, so the blocks can be dismantled and reused if needed. I think the biggest advantages of Polycare’s blocks are: 

• their use of low-carbon, high strength geopolymer concrete. 
• The block’s thin shell that takes up just 20% of the total volume. 
• And the fact that the remaining 80% of volume is insulation. 

#2 – MyIB

The second innovative block is Malaysia Interlocking Bricks or MyIB. Their bricks are made of local soil with a clay content of around 30%. This soil is mixed with cement and water and compacted in a hydraulic press under very high pressure of 3000 psi. Their bricks have consistent tongue and grooves on the sides, circular bumps on the top and a void on the bottom. All these features allow them to interlock with one another. The company estimates that this construction method is 9 times faster and 90% cheaper than conventional brick laying.

The blocks are also very easy to assemble. The first layer of bricks is attached to the foundation with a thin layer of mortar. After that, the subsequent layers are quickly and easily dry-stacked. Rebar and mortar is added in the voids of the wall for structural stability and reinforcement. Thanks to its smaller voids, this system uses 60% less mortar than conventional bricks.

#3 – JustBiofiber

The third innovative block is by JustBiofiber, a Canadian company that makes eco-friendly blocks of hemp, lime and water. The blocks consist of a biocomposite frame around which hempcrete is cast and cured. The heavy duty black frame blocks are used for tall walls, 30 feet high. The lightweight green blocks are used for standard residential construction up to 20 feet high. The inside and outside surface even have a scratch coat which makes it easier to apply the final lime and plaster coat.

The eight posts on the top of a block fit into holes in the bottom of the block above. The blocks have holes every couple of inches for running electrical conduit. A mortar made from lime and chopped flax is used to seal between each block. Glue is applied between the layers to attach the blocks together. The blocks can be easily cut down to size on a band saw or reciprocating saw.

• Hempcrete is comparable to high performance concrete
• It has a high load bearing capacity but it is half the weight
• It provides 10 times more insulation.

#4 – System 3e

The fourth innovative block is by System 3e which was developed in Poland. Their building blocks are made of perlite, a natural material of volcanic origin. The blocks have a characteristic tapered and self-anchoring shape. They click together without the need for mortar, glue or water.   These perlite blocks are fire resistant and chemically inert. They also provide good thermal insulation, sound absorption, moisture resistance, vapor permeability and resistance to pests and mold.

After assembly, a thin layer of cement and a fiberglass mesh is used on the interior and exterior faces for reinforcement. The building system is compatible with traditional finishes, like plaster. The use of perlite as an alternative building material is very interesting. Its insulating and fire resistance properties makes it an excellent structural material. The lack of thermal bridges is another advantage of System 3e given that these are a major source of heat loss. The only drawback is that you have to route out channels to run electrical conduit and plumbing, which can be time consuming and messy.

#5 – Gablok

The fifth LEGO-like building system is Gablok, which was developed in Belgium. These insulated, structural stacking blocks are meant to simplify and speed up the construction of homes. The outer container is made of OSB or Oriented Standard Board. The insulating core is made of EPS or expanded polystyrene with a graphite additive. The blocks are designed to fit together without any adhesive or fasteners. The system meets codes for 2 story buildings.

In addition to insulated blocks, the Gablok system consists of insulated partition walls, start and top rails, insulated beams and rafters and a floor system; everything you need to build the shell of your house. After the walls are assembled, you can choose any style of roof and complete the exterior and interior walls with any finish. Gablok claims that you can have your home completed within a week with little to no waste.