Just a few comments. Fireblocking See Diagram below from Fairfax County Virginia based on the 2009 International Residential Code. Keep the fibrous insulation out of that narrow gap between the outermost joist. Just use fireblocking to cover the space up once you've got in the insulation. Shiplap joints really don't need any more sealants. If you want, though, one is enough. Tyvek tape is fine. I always mention Tuck brand as it's the predominant brand in my area. Concrete screws and fender washers Leave them in place. Some municipalities require a mechanical attachment. Instead of using several screws per board, you might be able to run a couple of long 1x2s across a whole wall to press the XPS tight to the concrete. Baseplates I like the XPS under the baseplates for two reasons: 1) it keeps the wood away from any minor floods you might have; 2) it acts as a thermal break between the cold concrete floor and the framing. How close around electrical panels can I install the XPS? I usually frame around the panels and put a door on the resulting box. Then you can bring the insulation tight against the wood.

1. What kind of insulation and how much should I have put into the floor of the attic to bring it up to standard? Add insulation to make it R-38. blown in over the cellulose. If you can see the ceiling joists you need insulation! 2. Aside from making sure that vents in the floor of the attic that provide air flow are not blocked, what else should I look out for? Areas that leak air and transfer attic temps into the living/conditoned space. This can be oversized cuts around bath vans, kitchen vents, fireplaces and recessed lights. (to name a few) If you can make as complete as possible air barrier, then you can add additional insulation. The question then is..where to seal. Blower door test. Have the person you are going to hire to seal these areas there for the test. 3. We have a vaulted ceiling in the kitchen and living room. We were told by one contractor that blown in extra insulation in those areas is a good idea. Another contractor said not to bother. I think that your vaulted ceiling is what I call a cathedral ceiling. (one is more of a triangle than the other..) adding insulation on these slanted surfaces can be done, but again, after sealing all penetrations to the living space. The end walls (knee walls) of this area should also be sealed. I ususally use a 1' foam/foil sheathing board on top of the insulation in the knee walls, batt insulation is the only kind of insulation that can somewhat easily be installed, foil/foam board is installed with button cap nails. the foil reflects the heat back into the attic while the sheating board stops air infiltration and heat gain. We have insulation under the floor -- batting material in the ceiling of the crawl space. It's about 3 inches thick. Is there any value in increasing the thickness of this insulation? The hard wood floor are not cold to the touch in winter. Other than pulling it out and putting a couple of inches of foam insulation..I'd prolly leave it alone. You might seal leaks in the floors, pipe penetrations and such. Usually floors leak at the floor to wall junctions. In the years I have been in my house I have caulked all the base boards to the walls, and to the floors..same for the ceiling moldings. Stopping air infiltration makes it easier to heat and cool your home. Insulation slows down air flow, but it doesn't stop it. When air moves through insulation is robbs it of its insulating value. When air moves through the insulation into your home, it brings moisture, insulation particles, and ambient and higher temps. 5. The siding is made of that Masonite product that got a bad rap a few years ago. We have looked it over very closely and, after replacing it in a few places with Hardiplank where water damage got to it, we feel confident that the rest of it is okay. We understand that it's insulating capacity is at least as good as wood if not better. We think there's insulation in the walls, but don't know how much or what kind. We don't plan to do anything with that any time soon. Is that sensible? Again blower door test will tell you of the areas that leak. Measures and identifies air leakage areas. If you don't have insulation in the walls, holes can be drilled and insulation blown in, a hole at the top of each wall cavity and possibly one halfway down ..if the walls have fireblocking. Holes are then capped off with plastic caps. 6. We are replacing most of the window sashes with Energy Star rated windows, and are putting in new weather stripping where needed. Good deal! Low e..vinyl? Solar Heat Gain Coefficient SHGC .35 or less? 7. We have pull-down stairs to the attic. Is there a reasonably priced, sensible way to insulate the hatch? Or should I just put weather stripping there? Products like attic tents seal well. building a box as described above works well also, as long as it is airtight and seals well. I find that they have to have a little weight to them to acheive a good seal. Best of luck to you!

Brickeye also wrongly stated: "I think manhatten42 does not get it. The stud space IS closed by the bottom and top plates of the wall. You can leave drywall off and meet the code. You could drywall only the upper portion of a wall and meet the code, with nothing at the bottom of the upper drywall. The blocking is top prevent fire from moving from floor to floor in a continuous chase (like old balloon framing had). " Nope. No you cannot. Which is why the Code specifically states in 602.8.1 that spaces that are 'furred' be firestopped at the top and bottom of the 'furred' spaces.... And why I AM a certified code enforcement officer and mightyanvil and brickeye are not. (We reject these kinds of specious arguments all the time! lol) --------------------- The Code requires that ALL 'furred' walls have a fireblock at their top and bottom....(as well as horizontally)... And which practice the original poster decidely stated he would NOT do! --------------- The bottom line is that fireblocking MUST be maintained within framed walls regardless how it is maintained: ---by drywall ---wood blocks ---or other approved methods And the bottom line remains that what the original poster suggested REMAINS a CODE VIOLATION. Period.

Just to be clear, I don't see causation for the developer, it isn't that you and your attorney can't argue causation for the developer, feel free to sue him and roll those dice, but it is an expensive get. Your chances of winning are much less than they are against the builder, and you are unlikely to be awarded attorney fees on a negligence case with this many questions. You must show that the developer had a duty and but for neglect of that duty your house would not have these issues. There are many problems with this assertion, first, and hardest to overcome, is if you knew the approved builders before you bought the lot then you found them acceptable. You have to prove that the developer had a duty to the homeowner. Someone please tell me how selling a lot with certain covenants and restrictions creates a duty for him to fully insure the benefit of those covenants and restrictions that supersedes your acceptance of those covenants and restrictions. That is just one of the three things that you are going to have difficulty overcoming. Once you establish duty, you have to show that there was no reasonable action available that would negate the damage, noting that there are other builders available you would have to prove that they all have similar issues. Once you get past that, you have to prove that the developer actually neglected his duty, which since he has kicked the builder off the development is another tough get. It just seems like a tough win, that is going to cost more than you end up with. Sorry, but that is my opinion. ---------------- Along with my father I have developed several mixed use developments (homes, apartments and shopping), and I am currently a member of an LLC developing a small shopping/condo warehouse district development. I am not saying the developer will not want to help, I am saying as a developer, access is the leverage I have (the money that builders can make from me). Once the builder is removed he is going to tell me to go pound sand. I will happily testify on your behalf if need be, however, if I start paying for things to get done I am opening myself up to an argument that I accepted responsibility. As much as I want financing and publicity to be positive, that has to happen on the front end. I can't start paying for the mistakes that builders make without opening myself up to being responsible for every problem by every homeowner.