Building integrated heat pipes (BIHP) utilizes flat gravity heat pipes (FGHP) with the thermal diode characteristic and ultra-high thermal conductivity, which can transfer a large amount of solar energy to the interior walls. The interior walls with phase change materials (PCM) can store the solar energy transferred by FGHP during the day and release it at night, greatly improving the indoor environment. However, current research mainly focuses on specific case studies, analyzing a single parameter with other given parameters. Thus, there is a lack of systematic research on the key design parameters of BIHP under different climates and building forms, and it cannot determine the key thermal design parameters in the entire process of energy collection, conduction, storage and release. This study proposes a Morris sensitivity method to analyze the thermal design parameters of BIHP in light and heavy buildings in Beijing, selecting 34 parameters such as window to wall ratio and thermal properties of interior and exterior enclosure. The selected parameters are ranked based on the impact of building energy consumption during the heating season. This study compares the analysis results of light and heavy buildings, identifying the similarities and differences in key design parameters between the two types of buildings. Analyzing the directionality of parameter influence, it is found that the ideal BIHP is a building form with high insulation for the external envelope and large heat capacity for the internal envelope embedded in heat pipes. Analyzing the nonlinearity and correlation of parameters to obtain parameters worth further analysis can help improve and perfect the thermal design of BIHP.