Contemporary consolidation treatments for tempera paintings on wood substrates, particularly those found in the Qajar-era ceilings of Shiraz, predominantly employ water-based acrylic polymer consolidants and coatings such as poly(methyl methacrylate) emulsions. However, the water content in these emulsions poses a risk to the wooden support and the delicate tempera paint layer, potentially causing damage such as paint layer wrinkling, creep, and moisture-related degradation within the wood. This necessity motivates the search for a more suitable and effective alternative consolidant for these specific artifacts. In this research, polyvinyl butyral (PVB) was evaluated for its efficacy in consolidating the surface of these Qajar-era paintings. The study employed a mixed-methods approach, integrating literature review, field surveys, and laboratory analyses with quantitative and qualitative assessments. Ethanol was selected as the solvent for the PVB consolidant. It offers key advantages over water-based acrylic systems, including a significantly faster evaporation rate of the solvent, desirable penetration depth, and better reversibility. Experimental samples, modeled after artifacts sourced from the Zinat al-Molk House, were prepared to investigate the consolidation effects. We evaluated the impact of PVB solutions at concentrations of 1%, 3%, and 5% (w/v), as well as a binary mixture of 1.5% PVB and 1.5% Paraloid B-72 in ethanol, on the consolidation of the Qajar-era paint layers. The treatments were assessed before and after accelerated aging to determine their long-term stability. Characterization techniques included measuring penetration depth and both gross and net absorption of the consolidants. Furthermore, we performed pH measurements (Sithole method), colorimetric analysis, hardness testing, FTIR, and SEM evaluation. The experimental results collectively demonstrate that polyvinyl butyral is a suitable and effective consolidant for the conservation and preservation of tempera paint layers on wooden supports.