Q&A: A Forum for Green Building Experts and Beginners

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

The usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration:
Under the box labeled "More explanation," look for the words "File attachments."
Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


Passive House North West is planning a conference on Mach 2, 2012 at Portland State University’s University Place in Portland, Oregon.

The keynote speaker will be Jerry Yudelson. speaking on the topic “Climbing the Summit to Passive and Zero Energy Buildings.”

For more information, click here:

In PassivHaus | Asked By Martin Holladay | Feb 7 12
3 Answers


I'm finishing my basement and discovered the HRV inlet duct insulation is damp at the bottom portion of the 90 deg inlet (pic attached).

Is there a better way to insulate this duct? During cold snaps here in the Pac Northwest, the rigid duct condensates, so last year, I wrapped it with insulation.

thank you

In Energy efficiency and durability | Asked By Frank O | Feb 7 12
5 Answers

I'm sorry I don't know how to get back to my original question. Air Krete's brochure says ALL GREEN INSULATION . The salesman said Retrofoam emitted gases. Retrofoams brochure says no fumes gases or emissions. Then I googled and it seemed that the words that came up said Air Krete that is made from...yes Retrofoam made by Polymaster. I guess what I want to know is IF Air Krete is made fro Retrofoam? And is Air Krete All Green? (I got asthma from black mold)

In Green products and materials | Asked By Connie Lambert | Feb 6 12
1 Answer

The Passivhaus Institut has approved the release of Dr. Wolfgang Feist's response to the controversy surrounding the Passivhaus certification issued to the Rideau Residences in Ottawa. (For more information on the controversy, see Is This Building Passivhaus-Certified?)

After GBA published Dr. Feist's response last Friday, the Passivhaus Institut told us that the release of the letter was not approved. Now we have heard that the letter can be made public. Dr. Feist wrote:

In PassivHaus | Asked By Martin Holladay | Feb 7 12
3 Answers

UPDATE: February 7, 2012. Dr. Feist's statement has been released. Click here to read it.

On February 3, 2012, Dr. Wolfgang Feist issued a written response to questions about the certification of the Rideau Residences.

After I received the statement and posted it here, I received an e-mail informing me that the Passivhaus Institut in Darmstadt is requesting that Dr. Feist's statement not be published.

I am respecting their request, and have therefore removed Dr. Feist's statement.

In PassivHaus | Asked By Martin Holladay | Feb 3 12
1 Answer

I am planning on building a home in zone 3A (Dallas) by first erecting a metal building and then framing the inside. Plan is to use R-panel for outside and then 2x4 walls. What is the best way to insulate this including what type and location of vapor barrier

In Energy efficiency and durability | Asked By Greg Trojacek | Feb 6 12
3 Answers

Two-story home is located in Atlanta, Ga, and built in 1984. The house faces west. The bonus room over the garage has a separated roof from the main section of the house which make up most of the angle portion of the ceiling in the room. The roof has ridge venting.

The issue is continually battling temperature variations as I have tightened up the house with air-sealing.

In Energy efficiency and durability | Asked By Scott Razzino | Feb 5 12
4 Answers

I am designing a new house in Rhode Island. We are using 2 x 6 studs with 4 in. closed cell spray foam insulation in the walls, with 5/8 in Zip sheathing (taped) over the studs, 1 1/2 in EPS styrofoam over the sheathing and an outer layer of 5/8 in. Zip sheathing (taped) and cedar shingles as the exterior. Second layer of Zip sheathing is fastened with long screws into the frame.

In Energy efficiency and durability | Asked By Jim Mellowes | Feb 5 12
1 Answer

We just received a Venmar EKO 1.5 HRV. It is lined with some sort of plastic foam (styrofoam?) that has a chemical smell. Any one else experience this? Will this smell go away?

In Mechanicals | Asked By Robert Albano | Feb 5 12
3 Answers

I read on the internet.....Finally, there is a foam in place,cementitious insulation Air Krete that is made from...Yes,Retrofoam made by Polymaster.
My question The salesman told me that Retrofoam excreted gases! I could get Retrofoam cheaper than Air Krete but that it wasn't Green!
Was I lied to?

In General questions | Asked By Connie Lambert | Feb 4 12
Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!