N1102.2.4

Section N1102.2.4 is titled 'Access hatches and doors' and covers requirements for energy efficiency. The requirement for access hatches and doors separating conditioned and unconditioned spaces to be weatherstripped and insulated to a minimum value, access ways to equipment which prevents damage to insulation, and construction that prevents loose fill insulation from falling through an access hatch or door and maintains it in place is established. The purpose of this section is to assure that access hatches and doors maintain a similar heat transfer resistance as the surrounding assembly. There is an exception which allows for vertical doors that comply with the prescriptive requirements of this chapter. The purpose for this exception is to clarify that such doors are considered to be equivalent or better than the requirements of this section.

The model shows a partial ceiling with an access hatch to the attic which has additional pieces of wood to prevent the blown-in insulation from being smashed down when someone accesses the furnace as well as to prevent it from falling out of the attic. The space directly above the access hatch uses fiberglass batts which are adhered to the cover to remain in place as it is moved. Do the batts need to equal the height or the R-value of the blown-in insulation?