Indonesian government is accelerating the development of national housing through its stateowned company, in which all planning designs have been already established including urban design and urban revitalization. But unfortunately the detailed engineering of installation building, especially roof insulation building has not gotten much attention yet. Main contractor was paid for the project but the insulation should be an extra work to be paid due to its status as variant order. So, any kind of insulation types are pleased to be proposed. This paper proposed Material and Cost- Based methods that was studied by comparing three proposed materials from physics and economic point of view with its theory and simulation data whereas computer simulation also conducted. Evidently, insulation has an important role to be installed due to gaining solar heat reduction from solar exposure through the rooftop based on indoor thermal condition and energy of cooling utilities. Besides, those methods presented the simplified decision for company to select a beneficial material to be installed.
Keywords: Roof Insulation, Outdoor Air Temperature, Thermal Transfer