2x6 OVE framing report

[Danjoh99]

Someone mentioned the work by Siegel & Strain Architects with 2x6 OVE
(Optimum Value Engineered) framing. I found this Home Energy article
written by Nancy Malone of Siegel Strain:
http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/00/000314.html

The framing details are good, but lots of thermal bridges remain. And
it needs a slab insulation solution.

Dan

[Stefan Carpentier]

I wanted to comment and follow up on some of the conversations we had Sunday.

I think we do need a simple to use manual/hand book style approach to remodeling homes to the PH standard. I strongly believe we need to have ONE approach to ONE situation as a PH team. The only way to allow learning in a group like as diverse, creative and capable this is to make team decisions and stick to them as a team 100%. 

There is one BIG lesson I learned in my previous life, The way to find out the fastest whether a group decision was correct is to commit to it as a group and go down that path fully committed. If it was right, GREAT. If it was the wrong decision we will find out the fastest as a team if we go down that path as fast as we can. 

Let's create ONE handbook, with ONE set of "how to" instructions for ONE type of remodel.

CIAO

             Stefan

http://www-stefancarpentier.blogspot.com/

The best way to predict the future is to invent it.
Alan Kay

I get up every morning determined to both change the world and have one hell of a good time.
Sometimes this makes planning my day difficult.
 - EB White

[Graham Irwin]

Dan,

Thermal bridges are an important issue to mitigate, since in a PH,
they become much more significant from and energy loss standpoint and
a comfort standpoint - as most of the interior of the building gets
closer to design temperature, the cold spots are more noticeable and
more likely to cause condensation. Furthermore, calculating thermal
bridges is a bear in PHPP: in actuality, they need to be analyzed in a
2D heatflow program such as "Therm" and converted to a linear heat
loss coefficient "fudge factor" (¥ value) which is inserted into PHPP
as described on pp. 46-47 of the PHPP manual.

The issue of foundation insulation is critical, and one of the most
difficult to resolve, between seismic and termite concerns and the
fact that the only common structural material more conductive than
concrete is metal (i.e. rebar.)

Joe Lstiburek of buildingscience.com is critical of our practice of
placing sand between concrete and the moisture barrier. I wonder if
this might address the concerns raised in the last meeting by the
gentleman (whose name escapes me) who warned against insulating
beneath slabs. The sand seems like a possible source of voids, in
addition to a moisture magnet:
http://www.buildingscience.com/documents/insights/bsi-003-concrete-floor-problems
http://www.buildingscienceconsulting.com/resources/foundations/sand_layer_under_slab.htm

I recommend his book "Builder's Guide to Hot-Dry / Mixed-Dry Climates"
as a good primer for many issues building science related, though
some of his details are questionable: http://www.buildingsciencepress.com/store/SearchResult.aspx?CategoryID=-1

There is also a book "Details for Passive Houses" which has a lot of
details, along with precalculated ¥ values for many common thermal
bridges. This book deals with German details, however, and is probably
a better starting point than a solution:
http://www.amazon.com/Passivhaus-Bauteilkatalog-Details-Passive-Houses-Konstruktionen/dp/3211297634/ref=sr_1_2?ie=UTF8&s=books&qid=1229628519&sr=8-2

Graham Irwin
AIBD, CPBD, CGBP
Remodel Guidance
415-258-4501

Residential Design • Plans & Permits • Green Building • Period
Homes

[Graham Irwin]

I am doing a PHPP analysis of a project on a mountainside and am
trying to find an expeditious way of obtaining the data necessary for
entry into PHPP.

The shading is calculated with the inputs for the height (maximum) of
the "shading element" and the distance from that element to the wall/
window in question. There is also provision for a "seasonal shading
factor" (i.e, leaves on trees) and a "temporary shading
factor" (blinds and other moveable shading devices).

The main issue is the effect of the mountain top on the site. The
architect mentioned a "solar pathfinder" which I have neither
possession of nor experience with. Does anyone have any suggestions
for gathering this information most quickly and easily?

Thanks,
Graham

Graham Irwin
AIBD, CPBD, CGBP
Remodel Guidance
415-258-4501

Residential Design • Plans & Permits • Green Building • Period
Homes


On Dec 18, 2008, at 9:08 AM, Danjoh99 wrote:

>

[Dan Johnson]

In my experience hills and mountaintops never end up shading as much
as we think they will. Can you get elevation data for the building
and for the mountaintop (from a map or Google Earth?), then couple
this with distance in plan to get a cutoff angle?

The solar pathfinder is this semi-reflective fish eye lens
(http://www.solarpathfinder.com/PF-TC) that reflects all the
surroundings over a sun path diagram, so you can see when obstructions
may occur to your solar access.

I've found that modeling solar obstructions in Sketchup (3D drawing
program) is very productive. http://sketchup.google.com/
Also see this article on modeling shading devices in sketchup:
http://www.beyondpassivedesign.com/2008/08/designing-sun-control.html

--Dan

[Graham Irwin]

Good info, thanks!

The "catch" here seems to be the "modeling solar obstructions." While
valuable and necessary, it seems like it can lead you to do as-built
drawings of not only your project, but many surrounding ones as
well!!! ;-)

Graham Irwin
AIBD, CPBD, CGBP
Remodel Guidance
415-258-4501

Residential Design • Plans & Permits • Green Building • Period
Homes

[Babette Jee]

Archicad can also model day, time, location very specifically.
Surrounding objects can be modeled very generically.
--Babette

[Graham Irwin]

Vectorworks as well, I have done shadow studies and animations. The
issue here is measuring the height and distance to a ridgeline, which
seems to be the purview of a surveyor...

Graham Irwin
AIBD, CPBD, CGBP
Remodel Guidance
415-258-4501

Residential Design • Plans & Permits • Green Building • Period
Homes

[Graham Irwin]

http://www.nytimes.com/2008/12/27/world/europe/27house.html