<p>This study presents a physico-chemical, mechanical and microstructural characterisation of original mortars, plasters and stones from the early Republican-period Terzi Hasan Eroğlu House within the multilayered Stratonikeia–Eskihisar settlement in Türkiye. Detached fragments were analysed using loss-on-ignition, acid dissolution, granulometry, porosity measurements, point-load testing, XRD, XRF and SEM. The materials were identified as lime-based systems characterised by high porosity, low bulk density and low to moderate strength, supporting moisture regulation within historic masonry assemblies. Mineralogical analyses confirmed calcite-dominated binders and carbonate stones with limited pozzolanic contribution. Comparison with regional datasets indicates continuity of traditional lime-based construction technologies into the early twentieth century. The results provide performance-oriented reference values for the design of mechanically and hygrically compatible repair mortars in multilayered rural–archaeological settlements.</p>