Green Building How To Build A Conditioned Attic

The irc has permitted unvented conditioned attics since 2006 with certain requirements.

Green building how to build a conditioned attic.

You can reduce dust buildup using an unvented attic versus a vented attic. This has several advantages including less air transfer and what air does transfer is conditioned. Install insulation along the underside of the roof deck of an unvented attic rather than on the ceiling deck of a vented attic for either of two reasons. After experimenting with cellulose insulated roof assemblies and fiberglass insulated roof assemblies lstiburek began promoting conditioned attics.

Code requirements vary across the country. The attic space becomes indirectly conditioned as a result of the air leakage heat transfer and. Watch this if you ve not seen it. In warmer climates unvented attics can prevent the condensation that occurs on ductwork in some vented attic spaces.

During the 1990s the building science corporation received funding from the u s. Department of energy through the building america program to research conditioned attics in nevada and texas. 5 dumb ways to build in the south. My original plan was to build a conditioned attic and place 1 5 of foam xps board r7 5 installation on top of the roof deck and fill the old true 2x4 rafters and rafter walls with closed cell insulation and if able attach 3 of foam xps board r15 to the rafters in the attic.

The loss of energy efficiency means some designers choose to move the ductwork into the conditioned areas of the home and leave the attics unvented. To provide an unvented conditioned space for locating hvac equipment in the attic and or to provide a continuous thermal barrier for designs that have complex coffered ceiling planes and or numerous penetrations for lights speakers vents. In a roof attic assembly the builder has two choices. The acceptance of unvented conditioned attics continues to grow among builders and building officials.

The thermal boundary can be at the ceiling plane leaving the attic space above uninsulated and vented or the thermal boundary can be located at the roof line creating a sealed insulated conditioned or semi conditioned attic space.