Sub-scale model experiments are widely used in the design of natural/hybrid ventilation systems and the thermal mass of buildings to calibrate and validate simulation models, collect data, and guide preliminary designs. Defining a scaling law to relate a sub-scale model experiment to a full-size building is a good method to determine fabrication design and operation strategy. As a result, many previous studies have focused on airflow similarity between a sub-scale model and a full-size building in a steady state using dimensional analysis. These studies, however, lack integrated consideration of both airflow and heat transfer in a transient-state model. The purpose of this thesis is to build an analytical model for dimensional analysis in a simplified model and to define dimensionless numbers to consider integrated similarity. The thesis also discusses whether those dimensionless numbers can be applied to a complicated high-rise building. Both sub-scale and full-size simulation models are calibrated and validated using results of sub-scale model experiments. Subsequently, dimensionless results from both the sub-scale and full-size models are compared to verify the dimensionless numbers derived from the analytical model. Finally, counterpart results for a full-size model are calculated by the scaling law from sub-scale experiments for thermal mass application.