Material Performance and Environmental Response in Historic Masonry Buildings: A Multicenter Longitudinal...

Adaptive reuse can extend the service life of historic buildings, but its performance must be evaluated without assuming that more intensive intervention causes better outcomes. This multicenter longitudinal observational study compared 72 historic masonry buildings in Guangzhou, Nanjing, and Xi'an managed under conservation-only, material-compatible passive retrofit, or adaptive reuse with reversible environmental control. Archived baseline-to-month-12 wall-moisture change was -0.23 ± 0.95, -2.09 ± 0.78, and -2.37 ± 0.86 percentage points, respectively. In the primary ANCOVA, strategy was associated with month-12 wall moisture (F(2,61) = 40.96, P < 0.001); adjusted differences were -1.88 points for passive retrofit versus conservation-only (95% CI, -2.40 to -1.36) and -2.20 for adaptive reuse versus conservation-only (95% CI, -2.73 to -1.67), while adaptive reuse and passive retrofit did not differ (-0.32; 95% CI, -0.84 to 0.20; Holm-adjusted P = 0.222). The monthly humidity ratio showed no independent association with strategy (P = 0.410). In a transparent reanalysis of all five questionnaire outcomes, respondent-rated thermal comfort (q = 0.0038), functional fit (q = 0.0110), and heritage authenticity (q = 0.0038) were associated with strategy, whereas perceived air quality and overall satisfaction were not (both q = 0.592). Archived thermal-comfort-hour percentages, soluble-salt percentages, and monthly wall-moisture summaries were not used for confirmatory inference because their underlying classification, extraction/conversion, or acquisition/calibration records were unavailable. The supported findings are adjusted observational associations and do not establish causation.