Glass blocks have high thermal insulation values – superior to double glazing and equal to double brick walls. Glass blocks act as a thermal barrier, significantly reducing heat loss in winter and heat gain in summer. In addition, they are perfect for utilising the low-lying winter sun for heating.
A partial vacuum is created within glass blocks during the manufacturing process. This internal air space, together with their mass, guarantee that glass blocks offer a high level of sound insulation, superior even to that of brick walls of identical thickness. Acoustic insulation properties of glass blocks provide a noise reduction of between 40 and 50 decibels, depending on the size of the block.
Glass walls offer a high degree of light transmission; up to 79% of the available light. This is equivalent to normal double-glazed insulating panes. Various effects can be achieved using different patterns and surface finishes, and the atmosphere of a room can be altered dramatically using coloured blocks.
Transparency is one of the most important features of glass blocks. Virtually any degree of transparency or obscurity is possible with the use of clear, patterned or coloured blocks. From glass blocks which provide a clear view, to decorative blocks that break up images and refract light, as well as blocks with a satin finish on one or both sides which allow a soft light through, creating a discreet screen.
Because of their robust character, glass blocks are a deterrent to burglary. With the addition of reinforcing steel in the joints, glass block panels offer a further level of protection against intrusion. Bullet-proof glass blocks may be used where a high level of security is required. In ballistic tests using a standard configuration of glass blocks, these blocks did not shatter when they were impacted directly by bullets shot from a .44 Magnum, ensuring they meet the highest security standards.
The National Construction Code (formerly the Building Code of Australia) requires external walls less than 900mm from the boundary to be fire-rated for 60 minutes. Glass blocks satisfy this requirement. A glass block panel installed in a wall or floor is able to prevent the spread of fire and smoke for a period of sixty minutes or longer, depending on the block used.
Glass blocks have a high level of resistance to human impact, making them a safe alternative to glass.