[Greenbuilding] interesting house in Bulgaria

John F Straube john at buildingsciencelabs.com
Tue Feb 11 11:35:24 CST 2014


I liked the longish video as well because it lets you "walk the site" a bit.
Most of the expense I see has almost nothing to do with airtightness, which is good news.  It was expensive structure and lots of windows.  Pay back almost never works in these situations.  The energy cost for a decent size IRC 2012 or EnergyStar v3 house is so modest, it is really hard to get any payback of almost any energy investment.  People buy $4 latte's so they are hardly motivated by reducing the monthly energy bill from $120 to $100 by spending 10K on, say, good windows.  I have had a lot more success selling airtightness windows and insulation on the basis of improved comfort, health, disaster resilience, less dust indoors, quiet than I have had on direct payback.  Energy is cheap, and we are building new houses that are not expensive to run if you follow even modest energy standards. 
The airtightness was just Tyvek-type materials taped together. Which is also good news because this is relevant to North America.  It takes some fastidious detail, and that is really important for a contractor to learn, so I think the project video is good for that--- even more detail would be informative.  Getting to 0.12 ACH at 50 is pretty darn amazing (and likely pretty darn unnecessary for performance, but still impressive)
We have done smoke tests on commercial projects so that the contractor visually see all the leaks, and this is a powerful motivator in teaching the trades about how to get it tight.  It did not seem to show rigid air barriers, such as fully adhered membranes on OSB or taped joints in plywood much (there seemed to be one such location) which have in my experience been the easiest most reliable way to get really good airtightness.  Loose membranes like poly and Tyvek are a lot harder to get really airtight. Possible, even practical, just harder.

John

On 2014-02-11, at 11:56 AM, Sacie Lambertson <sacie.lambertson at gmail.com> wrote:

> A point of this site I appreciate is the overly long video detailing the construction of the house.  I found this very interesting.  Many on this site speak of the need to build tight but I am pretty sure most contractors don't know the true meaning of what 'tight' means.  Architects rarely detail this either. And while I presume most here on this forum understand these, at my end I plan to send the link to one of the best contractors in my area for what I am pretty sure will be his edification.  
> 
> It is an overly large and I'm sure very expensive house.  I won't take bets about its occupants being Passiv Haus trained either.
> 
> Re the cost of construction, it would be most interesting to account for this and compare that with the projected energy savings down the line.  It would not be difficult to do this except that it's Bulgaria.  Surely there is good data for this on our continent?  If knowledgeable architects and contractors had some of these stats easily at hand, it should not be too difficult to persuade less knowing clients to spend the money now to save it later.
> 
> Sacie
> 
> 
> On Mon, Feb 10, 2014 at 7:30 PM, John F Straube <john at buildingsciencelabs.com> wrote:
> Hi Sacie
> Thanks for this -- lots of construction info that seems quite familiar to my experience in Germany/Austria/etc region.
> This is a rather large, rather expensive house, with too much glazing necessitating rather high cost solar shades to manage overheating.  But should be able to get to their 38 target if the occupants are Passive House trained:)
> 
> On 2014-02-10, at 6:24 PM, Sacie Lambertson <sacie.lambertson at gmail.com> wrote:
> 
> > Check out this house in Bulgaria.
> >
> > http://dornob.com/eco-friendly-home-produces-more-energy-than-it-uses/







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