I've never seen house wrap used. I think it's a north american thing because your construction techniques often require it, like your non-universal adaption of rainscreen instead using single layer paneling. We just built a house and here (Finland. Sweden, etc) and we put the moisture barrier (special type of plastic and special type of tape) on the inside. This ofcourse requires a good mechanical ventilation in a modern house. The biggest reason for the air barrier is that fiberglass/rockwool's hydroscopic, in older houses they use organic insulation like sawdust that can withstand moisture better and since there is no barrier, the moisture continually moves freely frominside out and it can dry out. This isn't possible using fiberglass or rockwool style insulation. Rain screen is probably the major reason you don't need house wrap. Commonly here the exterior is first paneling, which is wood, vinyl hasn't caught on here and hopefully won't. Then comes an air space to protect the exterior grade drywall (OSB and such hasn't caught on either). Then insulation which is usually plain rockwool or fiberglass wool, 250mm I think was used in our house, then the moisture barrier comes, then another air barrier of 45mm (can also be filled with rockwool, a little insulation inside the vapor barrier is OK, but no more than that), then interior drywall. The main purpose of this is to prevent the barrier from getting holes in it when putting up paintings and such. So anyway my point is housewrap isn't anything that is super neccessary, we don't ever use it here, but we also only build using rain screen which makes house wraps unneccesary. IMO rainscreen is a simpler and superior way to build. I must say in our arctic climate I don't see how an exterior grade wrap with all the insulation on the inside wouldn't lead to severe mold issues in a very short time span, perhaps it works where it's warmer but here it looks like a disaster waiting to happen.

I would check out all the links that macv and others posted above. I see some new ones in there that I will check out myself, I am still learning something new on here every day! Some knowledgable people hang out here. I love the Boston Design Guide web site, macv! I have gotten an immense education in my quest towards building a home and it began over a decade ago with me picking out plans that I saw in plan books and online. Some of these plans were so unrealistic and ridiculous in one way or another, that I laugh when I look at my choices now. In my opinion, you have to cast a wide net, then narrow and rework your choices as you whittle down the list of things you need and some of the things you want. Yes, you could sit down and tell an expert at an architectural or design firm what you want, they can question you and do some calcuating and BAM, draft you some plans that would be excellent for your circumstances. If you have the means to to do this, I don't think you could go wrong, even if it is just to get them to tweak a plan for you that you have already decided on. I don't think the majority of people can afford a custom design done for you by an architect, but we can take some elements from those and use them. But the whole plan searching process is SO much fun! I literally get a charge when one of my favorite design firms releases new floorplans (something that is not happening much since the recession, but before that, everyone was releasing new plans almost weekly). Stalk their websites. Register on the site and sign up for all their newsletters to come to your email. In my mind, after you have this list of details you THINK you want in a home and you find ones that seem to fit your requirements, then you you need to stop and ask yourself, WHY am I drawn to these features? Is it purely for looks? Does my lifestyle actually fit these features? Will I actually use this space or feature? If I have to give up some pricey things to make this house happen, what is my list of priorities, what can I compromise on and what would be a deal-breaker for me? Look at as many actual photos of the houses as you can if there are any available. Keep clippings and old mags with examples of things you like. Learn the some of the terminology of building so that you won't be clueless. The most helpful adjustment in my mental thinking has been that I know now that I can adjust almost any detail on a plan. There is a cost involved, certainly, and sometimes the cost kills the idea, but almost any room can be renamed, repurposed, made bigger, made smaller. Walls can be moved and re-moved. But if you find that you have to make a long list of major changes, you probably would be better off making another selection that more closely fits what you want with fewer changes. I am providing links below to my personal list of sites that I visit to check out house plans. Happy plan hunting! http://www.dreamhomesource.com/ and http://www.eplans.com/ (the same company runs both these sites, but eplans has a price range feature that helps to keep you from being totally unrealistic about what you can afford) http://www.dongardner.com/ http://www.frankbetz.com/ http://www.stephenfuller.com/ http://southernlivinghouseplans.com/ http://www.designbasics.com/ http://www.designerdreamhomes.net/ http://www.nelsondesigngroup.com/ http://hgtvpro.homeplans.com/ http://www.danze-davis.com/search.htm http://www.mascord.com/Default.asp http://www.ahmanndesign.com/

I can't imagine why anyone would want to put narrow strips of roofing in hot asphalt or cold adhesive when they could cover the roof in a one piece (or factory seamed) single ply membrane. I would have to guess that the pieced together system is used for roofs with a lot of mechanical equipment and/or penetrations. If you want to include an internet link put it in the box provided and give it a name so we don't have to cut and paste to access it. Here is a link that might be useful: your roof link

The perm rating for exterior-grade plywood is what it is despite any physical defects typical in the material. While it has a low perm rating, it's a poor candidate to install under sheetrock as a vapor barrier. In my market, 1/2" CDX plywood costs roughly $.55/SF compared with 6 mil polyethylene sheeting which costs $.05/SF .... @Charles Ross, looking back at the picture I posted the plywood has a perm rating of .70 and the polyethylene sheeting has .06 --- the picture states anything with a rating less than 1 qualifies as a 'vapor barrier'. So the question of which is better I'm not really arguing, just expanding the conversation to show that there are different materials to use as a vapor barrier as well as the location of which to install it (climate concerns). With that said, what is better in terms of the rating regardless of cost or installation problems or concerns? Here in the south they not only put up plywood but then also wrap the house, usually in Tyvek. But the home I live in was built in the late 70's has either asphalt coated paper or some sort of aluminum coated paper. Another important difference is in my area the product is installed on the exterior of the house. I think a wrap would be a harder install on interior walls. I think if it were me I would choose the 'Vapor barrier paint or primer' for homes in the north where vapor barrier should be installed internally. The rating of the 'vapor barrier paint or primer' according to the picture I posted a few clicks above was rated at 0.45 which is almost half of plywood... but much higher than polyethylene at .06. Due to the ease in which the 'vapor barrier paint or primer' can be applied, the higher rating and no interference that the ply wood make due to the thickness of it, 'cracks and crevice' problem I mentioned... But the question is as someone who doesn't do this sort of thing... what is the difference of the rating between these different materials.... short of costs, installation methods or problems with such. Is a rating closer to 1 better than a rating closer to 0? That primarily is the point to everything I posted, it wasn't a venture off into the weeds. (What's the best in terms of the rating?)