Enter the gross area of the roof component in the Gross Area field. The gross roof area includes the area of all skylights within the roof. You must link the ceiling to the skylights within that ceiling. To link a skylight to a roof assembly, use the Move Up and Move Down buttons. The roof area should be measured on the slope of the finished interior surface.
Enter the R-value of any insulation to be installed in the cavities between roof structural members. All R-values should be rated R-values for insulation materials only. These values are commonly printed on the materials. The insulating values of other parts of the building assemblies (e.g., ceilings and air films) are already accounted for by the software based on assembly type.
Enter the R-value of any continuous roof insulation. Continuous insulation is insulation that runs continuously over structural members and is free of significant thermal bridging; one example is rigid foam insulation above the roof deck. All R-values should be rated R-values for insulation materials. The insulating values of other parts of the building assemblies (e.g., ceilings and air films) are already accounted for by the software based on assembly type.
If you have selected the Other roof type, enter the overall U-factor of the roof assembly, including exterior and interior air films. Do not include the finished ceiling in the U-factor calculation if the space between ceiling and roof structure is used as an HVAC plenum. Building departments may require supporting documentation for assemblies entered using the Other roof category and U-Factor field.