Thanks again, Wow, you have an enviable record with the utility bill reduction. I am not sure what your complaint about net-metering in LA is about. Could it be that if I produce more power than I use, I only get wholesale price and then only after I die? I have not looked into how it is done in other parts of the country. Maybe it is done better elsewhere. So far, I have not been pressured to buy more photovoltaic than I need. I am dealing with the big dogs in the region and a smaller NOLA-based company. The latter seems to be flexible while the former has a sales staff that seems to have "packages". The problem is that I have to decide what I need and that will not be easy. I understand that fixing the house first would be a better idea in a perfect world. There are some things that make that difficult. First, I dont know how long the generous Fed and state programs are going to last. Second. My AC is FUBAR. There are two, 2-ton, compressors, one rather old, feeding a split evaporator. One circuit in the evaporator is leaking. I have an estimate from the previous family that says it will cost $2K to replace. I guess it is a custom evaporator. We also have an unusual tax situation that makes it better to spread the costs out over a few years, though we could do a loan. One thing that I forgot to mention is that when the AC ducts were installed, the central hallway ceiling was dropped and, later, the ceiling in a closet and part of a bath were dropped all to accommodate ducts. Unfortunately, the areas appear to have been boxed off open to the attic. That is right, the attic "floor" is actually boxed "down". Part of this is under the furnace and air handler. I am having a difficult time figuring out what is going on because I can not see all of it. Sealing the supply ducts/boots to the attic floor will be a piece of cake compared to that mess. That is why I was relieved to know that sealing the attic was a great idea. Then I had to think about the flat roofs. Speaking of which, if I close off the flat roof from the gable, and leave the flat roof vented for now, I will need to add vents to let continue the air flow that enters through the soffit vents, right? Believe me, I am counting on variable speed equipment to adjust to my changes in the house in the next few years. For us, oversized, but adjustable will be a big boon. We are both gone all day so having a fast-cooling system that can throttle and control humidity will be nice whether ducted or mini-split. I have not looked at daikin. I have seen the Sanyo, Mitsubishi and LG "multi-minis" though. I will check them out. I have been to the HVAC-talk site, but not for a while. I learned a lot about AC and air quality there. I am a tech-minded guy, but I had a lot to learn about AC and humid climates since I moved here from drier places. I think I have read most of the stuff about hot-humid climates at the building science site, but I should check it again. Will you check the www.fsec.org link. I dont get a rational response. As a historical note. This home was probably one of the early adopters of central AC. There was originally a water-cooled condenser and the house still has three-phase power. There are some interesting-looking motor controls left in the attic. It is hard to say when the AC was first installed wrt the flat-roof additions. I suspect the first one was there because it is fed from the duct in the dropped-ceiling hallway. The later flat-roofed room in the back, with a lower ceiling, has AC supply that runs under the house rather than through the attic. Again, thanks from the bottom of my heart. You are very helpful.

this is what you have: Polyisocyanurate also known as polyiso is seen in all kinds of commercial building applications and more recently with residential building projects. Polyiso is typically used with a foil facing and it has an R value of 7.0 to 8.0 per inch of thickness. The reflective foil facing makes it an excellent insulation board when radiant heat is involved. The foil facing also makes it very easy to seal with good quality foil faced tapes. Cost = Polyiso is the most expensive of the foam board insulation products however it’s the highest R value. Polyurethane and polyisocyanurate are both closed-cell foams. They contain low-conductivity gases in the cells (usually one of the HCFC or CFC gases.) The higher R-Values (R 7.0 to 8.0) are the result of thermal resistance of the gases in the cells. This can lead to a couple of disadvantages including: off gassing of HCFC or CFC gases, and reduced R Value over time as the gas escapes. http://www.homeconstructionimprovement.com/foam-board-insulation-values/ as to fire resistance...I learned something! Polyiso Maintains its High Level of Inherent Fire Resistance All construction materials, including foam plastics materials such as polyiso insulation, must provide a suitable margin of fire safety. Among all foam plastics, polyiso possesses the highest level of inherent fire resistance due to its unique structure of strong isocyanurate chemical bonds. These bonds result in improved high temperature resistance (up to 390oF, more than twice the temperature resistance of other building insulation foams) which in turn leads to enhanced fire resistance. In addition, because polyiso does not melt or drip when exposed to flame but rather forms a protective surface char, its fire resistance is further enhanced, especially in terms of flame spread and flashover potential. Polyiso passes both the ANSI UL 1256 and FM 4450 fire tests without a thermal barrier. Polyiso, a thermoset material, stays intact during fire exposure in the ASTM E84 or "Tunnel Test.” It forms a protective char layer and remains in place during the test, thereby meeting all building code requirements and contributing to a fire-safe building. http://www.polyiso.org/?page=FirePerformance good links at this site too, for nerds like me who read technical sheets... If your install were tight to the roof, and installed air tightly the condensation issues would cease. contractor should have done his research, or spoken to someone who had experience with a successful install best of luck

Table 402.1.2 from IECC 2015 to current is best prescriptive guideline for cost effective energy efficiency. I doubt using weaker local amendments is good strategy. Some energy efficiency experts feel that R49 is good minimum for ceilings in ALL climates and would agree, if the ceiling is traditional vented attic where thick layers of insulation are easy to apply and affordable (loose fill). Some high performance projects in cold climates approach R100 for ceiling. These are international code minimum prescriptive numbers and it's easy to use other compliance paths to demonstrate equal total performance through other balancing improvements. Renovations of vaulted ceilings and insulative sheathing above the roof deck can make sense to go with weaker values. Spray foam applied to bottom of roof decks usually have substantial thermal bridging through rafters or truss chords, often more than the vented attics that prescriptions are based on so I don't think they deserve much leeway. Martin Holladay has the classic article on this common code violation. Efficient homes heating with mini-splits don't need heads in every room, but will need their doors open during hot or cold weather, a deal breaker for many. Then there is David's point about resale but I think good implementation could help tamp down this possible sentiment. Haven't built ductless yet but open to it if owners are. The efficiency one gets with Mitsubishi's smallest unit is unbelievable. One head replaced a whole house furnace in my personal small home, granted winter design temps are stretching it. Energy Star is for all homes. Homeowners or owner builders are eligible but may have a steeper learning curve to get the right details. Always involve a rater early, preferably with feedback during the design stage. Cpartist, sorry for your trouble. With everything you have had to put up with, it's not surprising they flubbed an important technical detail of your build. I think people who value efficiency have to do extra research to ensure they are getting the right feedback on their design and selections. The architect or builder should have the right knowledge and experience in your goals and I think the best projects are collaborative from the beginning. Most build teams valuing efficiency still include HERS raters (Energy Star) and mechanical engineers specializing in HVAC for services like Manual J, D, and S. Third party diagnostics, commissioning, and verification usually help ensure a good investment in home performance certifications like Energy Star.

Here is a general reference for flat roofs on homes if it applies to your situation. I've designed these roofs for large hotels, hospitals, dormitories, apartments and offices where cost could be justified by longevity so they were very expensive. I did a study of roofing systems for the State Dept. years ago but they were all on concrete slabs with equipment enclosures. None of them drained by scuppers or gutters except for overflow. Gravity draining to the exterior puts you into a special category that, to my knowledge, is not well documented. I would use a fully adhered or loosely laid single ply membrane and pay careful attention to venting if the structure is wood. You might consider a hipped roof with a slope of 1"+/- in a foot with fully adhered single ply membrane rooting over a recovery board over foam insulation board with perimeter gutters. It would appear flat from the ground.