In order to reach the Passive House Standard, an energy model of a building must be validated which calculates the yearly heating and cooling energy consumption based on local climate data and all of the specifics of the home. A very important part of this model is the thermal resistance or R-Value of the building envelope, the shell of the building that is in contact with both interior air on one side and exterior air on the other. These values are split up by surfaces, walls, roof, floor, windows and doors and your energy model helps you determine what values you need to hit to meet the Passive House Standard, often 1.5 to 2 times what is required by code. For the SURE HOUSE, we have designed our house to have an R-50 roof, R-37 walls, and R-30 floors. In New Jersey, code requires an R-39 Roof, R-19 walls and R-13 floors. These numbers were chosen because of the results from our energy model compared to the cost to insulate more. While insulating is cheap, there are diminishing returns the more you insulate. Therefore, going from an R-0 wall to an R-50 wall will have a much greater effect on your heating energy consumption than going from an R-50 wall to and R-100 wall.