Briquette is a building material which is produced by small enterprises and is widely used in some locations in Turkey. In this study, which is supported by the Turkish Scientific and Technological Research Establishment, an appraisal of the briquettes produced in Turkey was made. As the result of this appraisal a new briquette with improved qualities was designed. This new briquette employs the ventilated cavity wall principle. The hygrothermal behavior of walls with the new briquette was studied both theoretically and experimentally. It is shown that the walls with the new briquette performed much better than the regular briquette walls. Among the walls tested, perlite filled pumice concrete new briquette wall showed the best performance.