New lightweight granular materials, called ‘3I' loose-fill materials (Inorganic, Insulating and Incombustible), were developed in the LEEMA-EU project. They are based on inorganic polymers derived from mineral tailings, recycled glass and industrial by-products and are produced as lightweight hollow aggregates. They have superior thermal conductivity, reduced embodied energy and lower cost compared to currently applied bulk insulation products. They can be used for the insulation of cavity walls or between rafters to meet energy regulations. They are also used as lightweight aggregates in boards or blocks and filling of masonry block perforations. In this paper the focus is on their application as grains in cavity walls using a blowing machine. Two types of walls were studied: existing double leaf masonry walls and new lightweight timber-frame walls. The thickness of the air space and the size of the holes for blowing the grains differ considerably for both applications. The aim of the test program was to study the feasibility of using existing blowing machines. A commercially available granular material was tested for comparison. First of all, the characteristics of both materials were determined and will be presented. Secondly, test setups were developed for blowing simulation. Finally, since dust release is a big issue, different analyses were performed to compare the release during blowing. Recommendations on the settings of the blowing equipment are made. For timber-frame structures, the tests show feasibility when sufficient tube diameter is used to simulate pouring instead of blowing under pressure to avoid grain destruction. For double-leaf walls the tests are not successful due to powder formation. Other techniques need to be studied simulating more closely pouring (only possible for new-built walls). Conclusions on the dust release are that considerable lower quantities of fine dust are released for 3I loose-fill grains compared to the reference material.