How To Turn Attic Into Conditioned Space

Not addressed can lead to several problems.

How to turn attic into conditioned space.

Fine homebuilding more musings of an energy nerd ventilation requirements in the covid era. At least half of your attic space must be 7 feet high by 7 feet wide with a total of 70 square feet. The loss of conditioned air increases heating and cooling demand. Fortunately this is a fairly easy fix.

The attic is fairly small at about 1 000 sqf total. From my research it looks like the best option is to make the attic a conditioned nonvented space. That is it too will prevent moisture from penetrating into the attic area. However when open cell foam is installed without a vapor barrier which appears to occur often in real world applications the foam will absorb the water.

Any water that leaks through the roof will pool on top of the vapor barrier and possibly next to the sheets of decking on the roof. Pull down stairs won t work for an attic room so you must add a permanent staircase. Codes vary from place to place but the rule of 7 for using an attic as an actual room typically applies. I m unsure of what to do and i m unsure of the most economical way to do it.

The missing piece of information is those miserable little beasts called the building and energy codes. Use closed cell foam insulation. Once you convert attic space into living space you need to bring it up to the standards of modern building codes. Moving the insulation layer from the attic floor to the sloped roof brings the attic into the home s conditioned envelope and greatly reduces the energy penalties associated with attic ductwork.

You might open up your attic and find bare joists with fiberglass or cellulose insulation between the joists. Open cell foam when properly installed with a vapor barrier should operate very similarly to closed cell foam. The attic space becomes indirectly conditioned as a result of the air leakage heat transfer and vapor diffusion through the ceiling. Humid indoor air that escapes into the attic can condense on cold roof sheathing resulting in potential moisture problems.

Warm air that escapes into the attic in winter can warm the roof deck and increase the risk of ice dams. You can sister the joists by cutting 2 x8 boards the same length as the joists applying construction adhesive and affixing each to a joist with nails.