I sat in on a seminar last week at the Pacific Coast Builders Convention that was directed towards the upcoming changes in store for Ca. Title 24 2016.
According to Energy Code Ace, California’s current agenda includes all new Homes being built to be zero net energy by the year 2020. A very aggressive expectation by any stretch.
One of the main objectives of the new upgrades was to make attic spaces cooler in order to extend the life of our HVAC systems. Some attics can reach 140 degrees or more in the summer months and for our systems to perform in this heat they must work much harder. Not to mention the hot air needs to be pushed through the ducts before the new cold air can be introduced.
So there are 4 alternate options being offered for roof systems.
• Apply a 1” air space between roof deck and roofing for air to move freely and keep the attic cooler. There are new systems being developed to achieve this.
• Insulate not only the ceiling but the rafters above to help keep the attic cooler.
• Don’t insulate the ceiling but ONLY the rafters above. Thereby making the attic into conditioned space. This would require the attic to have no ventilation to not allow the cool, conditioned air to escape.
• Or place all HVAC equipment and ducting in a conditioned space as in below the ceiling. This would require soffits to be built under the ceiling level to accommodate duct runs in the conditioned area.

All of these options have mandatory provisions for wrapping all ducts with min. R4 insulation, a Hers test will now be mandatory for duct leakage testing, and all roofs will be required to be Sheathed with radiant barrier roof sheathing.
Another new mandatory measure is that ALL new residential construction will be required to have continuous 1” rigid foam insulation around the entire exterior. So you might want to do your homework now for system integration of housewrap, window flashing, foam insulation, and fastening of wood siding to the foam.
The new codes are set to take effect in January of 2017.