That is it in a nutshell.
That is it in a nutshell.
Well done.

Yea, a shed roof could make
Yea, a shed roof could make sense. I wasn’t specific in that I was thinking of a southern climate with slab on grade where the air handlers and ductwork would be in a conditioned attic (insulated roof deck). So a shed roof with an attic might be a viable option, but it would tend to push the air handler towards the high side of the attic, rather than the center and thus might result in longer ducts.

“So here is a question: What
“So here is a question: What is the “optimal” roof configuration for cost-effective energy efficiency, neglecting aesthetics for the time being? I would claim that it would be a gable roof with no valleys, at least 4/12 pitch, and with at least 8 feet of attic height at the ridge.”

I’d guess that it depends on how cost sensitive one is. Off the top of my head I would think a single-slope “shed roof” where the downward slope faces the equator would be in the top 3.

I looked up the requirement
I looked up the requirement again to be sure that I was right, but the minimum is 10/12, not 9/12, so it is even a little “worse” than I thought. I agree that it is nice to have plenty of room for mechanical systems in the attic, but this goes way beyond that, especially for relatively square floor plans like mine. I agree that a lot of this space can and sometimes is used for additional living space, but then you have add dormers for windows and have sloped ceilings that are hard to insulate and seal, so I don’t consider this to be a very energy-efficient option either.

So here is a question: What is the “optimal” roof configuration for cost-effective energy efficiency, neglecting aesthetics for the time being? I would claim that it would be a gable roof with no valleys, at least 4/12 pitch, and with at least 8 feet of attic height at the ridge.

I am in area where the HERS rating system is fairly new. Right now I am the only local person doing the ratings. The company that has been doing most of the ratings here have not been the most honest in terms of sticking to what should be done. So much so that the neighboring town finally caught on, and implemented an affidavit for HERS Raters. I have heard many stories from builders and trades of this company fudging the final score. So it will be interesting to find out if builders expect me to do the same.

A lot of new homes in the
A lot of new homes in the south are built on slabs so a 9/12 roof pitch allows for more room for mechanicals and additional finished space (builder upsell opportunity).

Besides 9/12 isn’t particularly steep. In fact it fits more in the “just right” range of roof pitches.

Yes, let’s expand the bubble!
Yes, let’s expand the bubble! As a Passive House homeowner, I do my part by hosting tours. We share utility bills as well as data on temperature and humidity. Being in the house gives the visceral feel of comfort. The people who come to the house may “get it” by feeling it, but how they convey and pass on the message is questionable.

That’s why I love your simple message: “Basically if you live in one of our houses you pay about $18 per month for all of your utilities, the air temperature and humidity are always perfect- like living in LA, your kids have no more allergies, and you never hear any sounds of equipment kicking on or off- it’s really really quiet.” It’s simple, memorable, and repeatable. I’ll use that line. Thanks!

I’m also sharing stories of my home renovation journey (my house is 96 years old and was renovated to meet Passive House standard 5 years ago) in a book. It’s written by a homeowner for other homeowners who wants a high performance green home. I think your clients and prospective clients may enjoy it. http://midorihaus.com/book/