I was visiting with an accountant today regarding the 45L Tax Credit.  I pointed out the differences between HERS 85 for Energy Star and the 50% reduction of heating and cooling for the 45L program.

 

He asked what you could do to improve the walls,  "2x6"?   I described 2x6 plates with offset 2x4s and the concept of basing everything on the 2 foot multiples.

 

What other concepts are out there for building the envelope?  Rigid foam then sheathing?  Other types of walls?  ICF's etc?

 

 

Views: 41

Replies to This Discussion

John,

    I have come from the custom home building side and we built extremely tight homes in So. Cal. First, your climate zone is important to what you should be using. The ICF or SIPS are very expensive and you can get similar results using everyday items. You can go green or go extreme green. That depends on the client and their budget.

   I build with 2x6's, 24" oc and air real well, especially around plumbing and electrical . I use bibs and spider/cellouse. look at homes that have aged 100+ years what are they made of ? New technology is great but is costly

Hi John,

There are many types of walls that are being used, and depending on the region, each one has it's benefits.

In colder climates, they're using more double-wall construction, which works well to eliminate thermal bridging and increase the R-Value. This is also known as truss-wall construction.

In mixed climates, like South Carolina and Georgia, a recently popular material is the aerated autoclave concrete products. HEBEL makes a variety of different products, including wall panels and standard solid blocks. These have thermal mass characteristics, high R-values, are made mostly of sand, and can be recycled.

A great method method of construction to increase R-value, that is also used mostly in cold climates, is PERSIST. Essentially, this is a build-up of layers of rigid insulation on the outside of the buildings exterior framing. In fact, it is attached after the sheathing. Not only does this method provide high insulation values, but it protects the structure, by keeping it dry and at the proper temperatures.

You mentioned ICF. A real good example of that, and one that is known as the first of it's kind (since 1972), is the RASTRA block. It has great acoustical and thermal properties, but it's also made from 85% recycled materials and is 100% recyclable. And, it's affordable, to boot!

I would be remiss if I didn't mention SIPS. Allison Bailes built his home with these panels in 2001, and has been a true believer since. They are typically 4'-0" wide panels of rigid foam sandwiched between OSB. They can be used for floors, walls and roof. They save on labor time, and have great thermal properties.

The opportunities are endless, and depending on the budget and climate, there is an ideal method and/or material.

How about spraying on or rollering on the envelope?

 

I have 25 years working with a radiant barrier roof coating, an Energy Star 'Cool Roof' coating.  We have proven it's effectiveness as an energy saver on roofs and are never questioned there.  However, in all these years I have dealt with maybe two dozen architects.  They have no problem with us as a roof coating.  As soon as we tell them it is also used as an interior / exterior paint for walls and ceilings, you can hear them hit the floor when they fall off their chairs.  Only two would spec us in for walls and that was at the insistance of local officials.  The architects would never seem to want to 'Step out of their comfortable boxes' with this idea.  I have heard statements like 'Energy Star does not recognize wall coatings or paint.  I can't specify this, I wont do it,  Noone else does it so I am not either".

 

Them I say the following;  "We earned the Energy Star as a 'Cool Roof' coating and you have no problem specifying us for roofs.  Now I put it to you; what type of heat gain / loss are we fighting on the roofs?"  "Radiant heat" was the reply.  "If the same roof coating is applied to the exterior walls, are we not fighting that same radiant heat energy of the sun on those walls in the hot months too?" 

 

The 'Envelope' can be created by coating the entire exterior of a building.  This puts the insulation on the outside where it should be   An even MORE effective envelope can be created by coating the interior walls and ceilings of a building. 

 

Our coating is an encapsulant material as well as a conductive and radiant heat barrier..

 

Check out our site at http://www.ct-texas.com  or http://www.monolitexp.com  and you will see what we have accomplishesd with it. 

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Profile IconKevin Jordan, Hannah Strong, Rich Snyder and 1 more joined Home Energy Pros
11 hours ago
EnergyLogic Academy posted events
11 hours ago
EnergyLogic Academy updated an event
Thumbnail

RESCAZ- RESNET Combustion Safety Testing: North Carolina at Wilmington, NC

November 7, 2014 from 6pm to 7pm
The health and safety of the home energy auditor’s clients should be the top priority when…See More
11 hours ago
EnergyLogic Academy updated an event
Thumbnail

RESNET Phase 2 Rater Training - Field Training at EnergyLogic Academy - Berthoud CO

September 22, 2014 to September 24, 2014
The EnergyLogic Academy will be hosting the second phase of HERS Rater Training August 4th - 7th,…See More
11 hours ago
Hal Skinner replied to Scott Katznelson's discussion Database of zip code or county by climate zone
"Hi Scott. I dont know of a database that you are referring to.  I was always under the…"
12 hours ago
Rich Snyder joined Rich Brunco's group
Thumbnail

Cape Cod Energy Pros

Recent BPI classmates, a place to share referals and informationSee More
13 hours ago
Scott Katznelson posted a discussion

Database of zip code or county by climate zone

HI.  I'm looking for a database that could help me assess the average energy use of a home (per…See More
19 hours ago
Hal Skinner replied to Hal Skinner's discussion The 'Touchy - Feely' sales pitch. in the group Radiant Control Coatings
"The 2nd bestsales tool I ever came up with.  aI will be happy to send anyone a test strip like…"
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service