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4 Answers

Swim spa addition (new construction) — PERSIST / REMOTE vs. closed-cell high-density spray foam

Hi GBA Community,

In Green building techniques | Asked By Dan Theman | Aug 6 16
6 Answers

Looking for the best way to re-build old gutted house walls in zone 4A.

I have abandoned our original plan to take off the 1883 original in-good-shape-siding to apply a rainscreen and insulate from the outside in because it simply costs too much given the attendant need to re-jigger the soffit and trim. So, leaving the siding on, how would you suggest I most efficiently and effectively still install a gap between the siding the the interior insulation? I've seen several options, Mooney wall, the Chautauqua Cottages system/other. Swimming with choices I would appreciate some balanced verdict about a best system for rainscreen, air barrier and insulation.

In Green building techniques | Asked By Sacie Lambertson | Aug 4 16
6 Answers

HRV versus ERV

I'm a retired builder and have a HRV in my 10 yr old home. I've heard a lot about ERV's. My question is what does an ERV do and how does it differ from an HRV? I live in Golden B.C. Canada and heat my home for 8 mths. of the year.

In General questions | Asked By Jerry Lawrence | Aug 6 16
3 Answers

How to brace a truss roof without OSB or plywood?

We are putting up a cathedral roof structure made with engineered trusses, however we are putting a metal roof on it. I would like to avoid using sheething and would prefer to use vertical 2x4 channel for ventilation with furrings on top to screw the roof to. Are the furrings and metal roof enough for bracing? Can metal T braces be used?

In Green building techniques | Asked By william murray | Aug 9 16
58 Answers

Transoms and Ductless Minisplits


I am trying to heat and cool my second floor with one 12,000 btu ductless minisplit. I have heard that this is possible if I keep the bedroom doors open during the day to facilitate circulation of the hot or cool air.

However, does it get uncomfortable quickly in the night when the doors are closed. If so, I was thinking of putting in operable transoms over the doors. The only problem is they are kind of expensive (~$275 from transomsdirect.com). Attached is my floor plan. I will be putting ceiling fans in each bedroom so maybe the transoms would be overkill?

In Green building techniques | Asked By Jimmy Nguyen | Mar 10 16
3 Answers

Do I need an exhaust fan in an unfinished garage?

Hi all,

Building a tight house and planning an exhaust-only ventilation strategy, depending on the blower door test results. However, we are having an attached garage, so I'm worried about air quality with an exhaust-only strategy.

On the other hand, the garage is going to unfinished. I will have to finish the shared wall between the garage and the house, but the rest of the garage can be unfinished. This includes no ceiling, exposed roof trusses, all he way up to the roof deck. I am planning gable vents for the roof ventilation strategy.

In General questions | Asked By Clay Whitenack | Aug 9 16
2 Answers

Studs for use with a single top plate

I work with Habitat for Humanity in upstate SC (zone 3), and we are looking to incorporate advanced framing techniques, one being the use of a single top plate, rather than a double top plate. However, this presents the need to change our stud height.

The new stud height would need to be about 94 1/8" to keep an 8-ft wall height. However, no lumberyard seems to carry this height. Thus, it seems they would need to be custom ordered, which would likely cancel out the savings we would get from eliminating the double top plate.

In Green building techniques | Asked By Dylan Hillman | Aug 9 16
4 Answers

Forced air heat register location

My heating contractor wants to put the heat registers along the outside wall, near windows, the traditional way of doing things. My thought was to minimize ducts and the associated losses and keep them centrally located, with at least one in each room. With all the talk here of using centrally located minisplits and that working out OK, I don't see why I need heat regs along the outside wall. I can see it being a little better, but not necessary in a house with pretty good windows, air tightness, and insulation. You don't need passive house levels to pull this off do you?

In Mechanicals | Asked By Brad H | Aug 5 16
15 Answers

Seeking insulation recommendations

I work with Habitat for Humanity in upstate SC (zone 3 - warm-humid), and we are researching practices to improve the energy efficiency of the houses we build.

We have been insulating the attic ceiling with blown-in fiberglass but are leaning towards insulating the whole building envelope now (cathedral ceilings and sealed crawlspaces).

First, is it cost-effective to put the HVAC unit and ductwork in the conditioned attic rather than the crawlspace?

Second, what type of insulation should we use in the roof?

In Green building techniques | Asked By Dylan Hillman | Jun 23 16
3 Answers

Becoming a green building consultant

Out of curiosity, what would you guys suggest as a way to go about becoming a green building consultant? Are there industry accepted certifications people seek out?

I'm rebuilding my home myself and really enjoy researching and implementing these green building techniques. I'm in North Carolina and see new homes flying up with passively vented crawlspaces and quiver. I left a note on one builders foundation "It's not to late! Please consider http://crawlspaces.org/"

In General questions | Asked By Michael Bender | Aug 9 16
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