ABSTRACT As ecological architecture and green buildings have become essential in the fight against climate change, earthen architecture has an undoubted role to play in achieving this goal because of its numerous benefits. To help providing a better understanding of the behavior of earthen materials to fulfill modern architectural needs and to preserve earthen heritages, this study aims to investigate the effect of stabilization using Portland cement and quicklime and that of reinforcement using date palm fibers on the compressive creep, ultrasonic properties, and swelling of adobes, besides their impacts on physical characteristics. One of the earthen heritages in Algeria is taken as a case study, and various adobe mixes were examined to attain this objective. The outcomes revealed that stabilization overall improved the properties of adobes, unlike the mutable impact of fibers. Stabilizers played an important role in reducing creep, while fibers reduced the creep of the unstabilized adobes and those with 6%PC-3%QL, but withdrew the positive effect that was offered by binders for adobes with 10%QL and 3%PC-6%QL. Water absorption and swelling were reduced by stabilization, but both increased with the presence of fibers. The changes in ultrasonic characteristics showed a good correlation with those of compressive strength.