I agree the end product is only as good and sustainable as the design,  
in combination with it's technologies applied  correctly. I believe  
that's what we are all commited to. There will always be different  
paths and priorities. I was sure that you were going to advocate the  
tent option and probably do prefer tents over living in a foamed  
house. Clearly my priority is the easiest path to high R-Value,  
sacrificing some petro chemical to save more petro chemical. I admit I  
also use I products like Grace Vicor, etc.  in valleys, around  
openings, etc. to protect from water intrusion (with considerable  
attention to the drip path). I think these are good technologies (yes,  
not great - great Would be fool-proof), but they can be misapplied and  
as you stated - over applied, which could trap moisture, especially in  
combination, over large, adjacent surfaces.  We use insulation baffles  
within rafter bays, which addresses this 'trapping' conflict, although  
a membrane breach will most likely go unnoticed.  Nothing beats  
construction moving at a measured pace, with time to observe  
performance deficiences and make modifcations.

Here's my regional argument. I believe that you live in Vermont. I  
live on Long Island. Fuel costs are much higher here. You can spec the  
less expensive, more environmental cellulose with half the R-Value,  
burn wood, save money and go skiing, while we struggle to pay off our  
excessively high real estate-valued lives.
Looks like you took the right path based on the correct priorities.

I am interested to know what you think the ideal thermal envelope  
consists of?

Appreciate your postscripts.


SDR & Associates
131 Cedar Street
East Hampton, NY. 11937
(631) 324-8868
(631) 324-0900 ~ fax

On Mar 12, 2010, at 12:13 AM, Robert Riversong <[log in to unmask] 
 > wrote:

> --- On Thu, 3/11/10, Samuel Robins <[log in to unmask]> wrote:
> You site only extremes. Life has compromises. The perfect is the  
> enemy of the good. You could debate every position and forever be  
> confined to a tent.
> The examples I give are legion, hardly extreme. In fact a central  
> element of the CNRC MEWS study, as well as the Florida Solar Energy  
> Center study (two very mainstream groups) was to introduce the  
> inevitable minor leak into wall or roof assemblies. In both cases,  
> foam-insulated or foam-sheathed envelopes got failing grades.
> Yes, the perfect is the enemy of the good. Which is exactly why I  
> draw attention to the absurdity of the "perfect wall" such as Joe  
> Lstiburek and many others advocate. An impermeable foam plastic box  
> performs only as long as the building starts out perfect and remains  
> perfect for its useful life. Neither case is either likely or  
> reasonable to consider.
> The most foolish approach to any technology is to try to make it  
> "fool-proof". What is required for durability and the health of its  
> occupants is to design and build a house to be "fail-safe". All  
> human artifacts fail, and most begin their lives with inherent  
> flaws. A resilient structure can tolerate minor failures. A non- 
> resilient structure cannot.
> In a house assembly, resilience requires materials and methods which  
> allow a structure to dry when it - inevitably - gets wet, and to  
> buffer (absorb and release) excessive humidity when the mechanical  
> systems meant to control it either are overwhelmed, under-perform  
> for lack of maintenance, or go down when the power grid crashes.
> Building hermetically-sealed boxes and calling them homes fit for  
> human habitation contradicts basic physics, undermines biological  
> integrity and defies common sense.
> - Robert Riversong
>   master housewright, building scientist, philosopher and prophet  
> for our times