I think they would be more receptive of it if some one came out and said here this is what you need and this is what it adds on the bottom line. They think it will add thousands and thousands and the house wont sell. When in reality … it wont cost nearly half of what they think. the house will still sell and the buyer will sing their praise for how cheap it is to heat and cool their home and how wonderful the air feels.

They block good things for no real reason because even if a house costs 5,000 dollars more …. no one is gonna care. But that can significantly change their heating cooling and comfort in the home which ultimately helps everyone with power consumption. Mr builder don’t you want to say “I’m the best because your gonna love not paying so much to heat/cool your home. And in our perfectly designed HVAC system your going to breathe better and live better.” That 5,000 uptick in cost….. nothing. Oh wait, you made more money because more people bought your homes, I’M sorry.

Its a shame they don’t use their heads for more than a hat-rack.

https://www.gwinnettcounty.com/static/departments/planning%20/News_and_Notices/Notice_bldg_inspections_insulation_inspection_201612.pdf

For example, as an alternative, a builder may choose a lower efficiency heating/cooling system but offset that with better insulation and windows, etc. Or a builder may use minimal insulation, and have 6 or 7 or 8 ACH50, but have low duct leakage to outside with the ducts in conditioned space, etc, and put in a heat pump water heater as offset?

I am not arguing against lower ACH50, necessarily, but setting up certain ventilation systems in Georgia tend to FORCE the need for additional dehumidification with both requiring increases in energy usage. Seen it too many times in my work. I am still not sure what a good, low cost (to run and/or install) ventilation/dehumidification system is for a fairly large house in a 9 month high humidity climate. I am very open to suggestions–as are my clients.

JC, here are my answers:

JC, here are my answers:

1. Yes, you absolutely can hit 5 ACH50 with house wrap. See this article with test results from a project I worked on in 2011:

Does Your Air Barrier Work in Both Directions?
http://energyvanguard.com/blog-building-science-HERS-BPI/bid/59648/Does-Your-Air-Barrier-Work-in-Both-Directions

It’s rare to see house wrap installed well, however, so while possible, it doesn’t happen often.

2. Yes, the 2015 IECC does require better insulated walls in climate zones 3 and 4, either 2×6 with R-20 cavity insulation or 2×4 with R-13 cavity insulation + R-5 continuous insulation. Climate zone 2 is still allowed to have R-13. Unfortunately, this was one of the things that’s not going to make into our Georgia code. It’ll remain R-13 statewide. You gotta pick your battles and that was one we decided to let go.

Gerry Whelan wrote:

Gerry Whelan wrote:

There needs to be more value placed upon the performance of a building rather than granite counter tops – and that is with both the builder and the buyer.

Hear, hear! That’s what I’ve been preaching here for a long time.

Well, that’s a bit of an

Well, that’s a bit of an exaggeration, Thomas, but you’re right that 7 ACH50 isn’t a place to stay. It’s a starting point. It’s the training wheels for air sealing. We’ve been there for six years now; it’s time to move on. Spray foam and concrete wall panels are one way to get there. Taped sheathing and fluid-applied membranes also work, as do many other techniques. I built a house out of structural insulated panels and hit 1.7 ACH50 — before I’d ever done or even seen a blower door test.

I would not say that concrete
I would not say that concrete is the way forward from stick framing in order to deal with a joint issue. That would ignore the embodied energy and all the other (very weighty) differences between the two materials. There needs to be more value placed upon the performance of a building rather than granite counter tops – and that is with both the builder and the buyer.
Other nations build better buildings using the same materials. The American domestic construction market gets away with square footage and kerbside appeal over performance and longevity.

Mike, I just heard last week

Mike, I just heard last week about your 3 ACH50 rule for requiring ventilation. I think the reason behind that is moisture because almost anytime you bring in outdoor air in Florida homes, you’re also bringing in a good amount of water vapor. Still, it’s possible to ventilate less airtight houses without having moisture problems. It might mean supplemental dehumidification, but that’s what happens in a humid climate when you kill off a lot of the sensible load.