I absolutely agree with you and understand what you are saying. When we were sitting with our designer, every time we wanted to make a tweak or a change his first comment always was "I need to see what that will do to the elevation, it may not look as good".

From the start, we've told him we didn't want a cookie cutter house, we wanted some character. We were more concerned with indoor character than exterior character however, and maybe we didn't communicate that very well. There are obviously some changes we can pull from your analysis that would be pretty easy. I really like the ideas about moving the west wall out to match the fireplace as well as making the study/bathroom/laundry room one common wall. I also think we could square off the foyer and hallway wall easily. I don't think we'd miss the bump out in the master, but the one in the kitchen is something my wife has always really wanted (Damn it pinterest) ;-) I'll admit, I like the look of it as well. How do we make sure it's properly sealed and a good thermal break?

I think around here, unless we hire someone remote to re-do our home design (which we are actually considering), getting a very efficient house is probably the best we can hope for but I doubt net-zero is attainable...

Assuming the backside of our house is direct south, would we be a candidate for solar panels?

If you have an unbroken south facing gable pitch on the south side you should be able to fit beacoup PV wattage up there. If it's cut up by valleys skylights vent stacks and dormers you're screwed. But since there doesn't appear to be significant bump-outs on that side, and appear to have an east-west ridge line for the major roof, prospects for large amounts of solar look good!

How you achieve the thermal break at the oddball corners depends a bit on what your whole-wall-R goals are, and the selected method for achieving that in the rest of the house. If doing it with thick exterior rigid foam the problem is how you deal with attaching the siding at the odd-angle exterior corners without flapping in the wind since the foam will project out past the framing. You hardly have to think about it with 1" foam, but at 2, 3, 4" it gets progressively more problematic. If you build that wall using a double-studwall approach it's a bit easier, but with that approach you have a significantly fatter wall. There are options, but you have to have it all figured out before you pour the foundation to end up with something that's easy to build in a reliably tight fashion. (I'm not sure if there are any standard detail drawings of those sorts of corners downloadable from the GBA blog site, but for a 10 day free subscription you can probably find out. You might try to find detail drawings of odd-angle corners on the Building Science Corp website too.)

Any idea (ballpark of course) what a beacoup PV wattage would cost me to have installed? I don't know if we're talking $10k or $100k...

There's a couple of factors that make it hard to answer:

I can't read the dimensions very easily on the drawing, nor is there a ridge line demarcation, making it difficult to estimate the total square footage of available south facing roof real-estate. With typical commodity panels you can expect to fit about 10-11 watts (DC-peak) per square foot of panel. For higher efficiency but still standard production panels that becomes 13-14 watts/ft^2.

There is also incremental efficiency improvements going on. Five years ago a commodity panel was running 12-13% efficiency, and premium goods were 16-18%, but now commodity panels are 15-16% efficiency and the higher efficiency panels 19-21% (with a few in the 22% range.)

The installed price of PV drops by somewhere between 22-30% every time the production/installation doubles, but prices vary quite a bit by location. In the US the installation rates have been doubling every 18-22 months for more than 5 years. The average installed price of small-scale rooftop PV in the US as of Q4 2015 is running a bit less than $3.50/watt, but there are locations in the US where the installed pricing is closing in on $2/watt on it's way down, and other places where it's north of $5. You can probably hazard a pricing guesstimate looking at recent comparable sized arrays in your state on NREL's database:

https://openpv.nrel.gov/

These are the prices before any subsidies are applied. The 30% Federal Income Tax rebate subsidy was re-upped for a few more years just in the past few days, and according to the industry analysts, that boosted the anticipated installation rate by about 54% over what it would have been without that subsidy:

http://www.utilitydive.com/news/solar-federal-tax-credit-extension-could-boost-installations-54/410991/

That subsidy extension should accelerate the rate at which the installed price of PV drops, since in higher electricity cost states it's already cost-rational to install PV at $3.40/watt even without the rebate subsidy, and with the subsidy third party solar companies can and do install panels on residential roofs for $0, and sell discounted electricity to the homeowner under power purchase agreements. (Which are still dis-allowed in some states.) http://apps3.eere.energy.gov/greenpower/onsite/solar_financing.shtml

So...

...summing up:

The total DC-watts you can get up there depends on how much unobstructed roof area you have to work with, when you decided to buy ( incremental improvements), and whether you opt for a commodity efficiency panels or a higher efficiency panels.

The total COST out of pocket can be anywhere form $0 to something on the order of (70% of $3.50/watt=) $2.45/watt or less this week, but before the tax subsidy drops to 26% in 2020 it's likely to come in well under $2/watt net, maybe even closing in on $1 / watt (in my more optimistic dreams. :-) )

I doubt that you have more than 2000' of exploitable roof, maybe not quite 1000'. But a house built to DOE's Zero EnergyReady standards won't need anywhere near (10 watts/ft x 1000'=) 10,000 watts of panel to hit Net Zero Energy in a zone 5 climate, but it may well need more than 5,000 watts. (See: http://energy.gov/eere/buildings/zero-energy-ready-home ) I'm pretty sure you' d have more than 500' of usable roof if you keep the southern pitches free of valleys, flues, plumbing vent stacks, satellite dishes, etc.

So, $2.45 x 10,000= $24, 500 is probably the upper bound of what it would take to do the whole shebang, covering your entire annual energy use, provided you build the house with decent (but nowhere near PassiveHouse) thermal performance, and are building right now, this year. If building in 2019 the PV portion could be under $15K out of pocket for a 10KW grid tied PV array, under $10K for something that does it all in a very-efficient house.

That might seem like a reason to wait, but depending on how much of it is financed and your tax bracket it can end up better to bundle the PV in with the house mortgage, since the interest of a house mortgage is tax deductible, whereas financing for just the PV on it's own would not be. Also, the state regulations on PV are moving targets, and in some states net metering at retail may go away by 2020, but most existing solar would likely be grandfathered in. Many states have (somewhat arbitrary) caps on the total amount of distributed PV can be net metered at retail in the state, and you can potentially get boxed out there by waiting too long as well.

One can also ground mount solar panels (depends on the site).

Dana thank you so much for all the excellent information.

Jonr- I don't think I'd want that. We won't have a ton of yard space that won't be shaded by woods around us. I think we should have plenty of roof line, and since it's a new house now is the time to make the design work with these things in mind.

Is there a certain pitch that's best for roof mounted panels?

It's not that sensitive - I'd use this, being careful to adjust for any net metering distortions.

for comparison, I'm thinking of pulling the trigger on US made panels and either Enphase micro inverters or a single SMA inverter and quotes are around $3.50/watt installed , and $3.0/watt for Chinese panels. Somewhere closer to American prices for LG Korean panels.

My roof is 34'x16.85' about 572 sq ft and most companies are saying they can squeeze 10 rows of 3 * 285 watt SolarWorld panels on there. - Although this is more than I need. I'll probably end up with 2 rows.

Posted By BadgerBoilerMN on 04 Dec 2015 04:50 PM
We find can help if you send a plan. The further out in the country you go the harder it is.

Better late than never right? Just sent it to you.

I'm still working on figuring this all out....

We had to take a little break due to some family health issues, but we're looking to get started back up soon.

I spoke with an experienced passive house designer. For their specially designed ICF's we're looking at almost $200k installed for the basement, main floor, and garage. Basically they'd build the shell, then it's up to us to complete. If that's half our budget (or more), what are the chances we can finish the house at under $400k? The land is not a factor, we own it. I start adding up a septic system, HVAC, kitchen, siding, plumbing, electric, flooring, etc - it adds up fast!

Hi. 200k seems awful steep for a shell. Does that include windows, doors, roof, siding and insulation? What brand ICF are they using and how are they specially designed? Thanks in advance for your answers.

If you are looking for ranch home advice the I would like to suggest you atomic-ranch.com.

If you're looking to read up everything you can, I think these two articles would be helpful: Which types of flooring are best for radiant heat? -and- Install Your Own Radiant Heat

Electric radiant is rarely a smart choice and contrary to the poor articles noted you can retrofit hydronic radiant heating practically anywhere.

As for flooring; you can use any flooring you like. Some are better at conducting heat than others. The manufacture of my pre-finished 3/4" T&G oak specifically excludes radiant heating in their installation manual. Apparently regarding, correctly, radiant heated floors as too small a market to bother with. Mine has been in since 2011, no problem. The engineered bamboo, both supposed to be "made for" radiant heating, cupped, curled and cracked, ever so slightly. Go figure.

We just had lunch at Potosi Brewery on Saturday.

Thank you for reviving my thread, we finally have a floor plan that is a little more simple than the last, and we are ready to start moving forward. @BadgerBoilerMN, I've emailed you to get the ball rolling for some possible design services.

Making my day.

?

A radiant heat product like Warm Waves is virtually maintenance free and can be put under any flooring. It can also be put into concrete. Doing Geo Thermal on top of radiant is redundant and unnecessary. Most of our clients go radiant only with AC for cooling. Warm Waves uses Far Infrared and is more efficient than it's competitors. Also easier to install.

For your envelope, you might want to look at a Steel SIP like ThermaSteel. ThermaSteel, combines 4 processes in one: framing, insulation, vapor barrier, and sheathing, making building faster. It is about 138% more efficient than a traditional framed home using 2x6 and avoids thermal bridging. It is mold, mildew, and insect resistant, reducing allergens and other such issues.

Look at www.hi-techbuilding.com. There is a lot of information on these products for you to peruse. Give us a call if we can help.

Well I lied, our contractor fell through (thankfully actually, more drama than we estimated) and we have a new one. We're going through a bit of a re-design with a new GC, and we are super happy with him. We're working on incorporating a lot of the advice in this thread into the new design. We are not going to go with ICF's, there is just not enough expertise here. I've exhausted that.

I am now interested in building a "better than code minimum" home. I hope to use much of Dana1's advice. And @BadgerBoilerMN what do you do in Potosi? That's only maybe 1.5 hours from us. Are you able to install in Iowa?

Also I'm wondering about 2x4 with external foam sheeting versus a double 2x4 wall.... The moisture issues I've been reading about with a double wall make me nervous.