Net Zero Off Grid Prefab House Kit Update: Finishing Around Foundation

In previous posts I mentioned not only the importance of having an energy efficient, insulated house (our passive solar prefab house kits, are made with structural insulated panels, or SIP) but to remember to not only have energy efficient walls and a roof, but to also insulate underneath.

So before we poured our concrete slab foundation, we laid down foam.
(Which you can order from the factory if you like...)

Now we haven't yet infilled back the dirt from the home site, and it is time to finish the final insulation not only *under* the foundation, but *around* it.

With temperatures in the 50's, we headed out to the off grid, net zero passive solar prefab house kit for a weekend of work.
Here is what we're doing:

1. Self-adhered rubber against concrete (or waterproofing paint) will be applied to the exposed *sides* of the foundation (underneath is already lined with foam) then lined with foam.

[In case you are reading this years from now, this winter was The Winter - snow snow snow, wet wet wet, and because of that we're taking extra steps in waterproofing so that the next Hundred Year Dumping Of Slush will allow us to remain dry and clear of the wetness that came down from the fields this time and against our unfinished / unsealed foundation.]

2. Attach rigid board along the sides, all the way down as possible, which will be held in place by infill

3. Flashing will cover up aesthetic appearance of the insulation

4. You can also dig a trench around the house kit so that any water that would fall off the roof would fall into the center of the trench. Infill with gravel and soil, and even better- put some perforated drain pipes around edge.  To prevent dirt from filtering down the gravel and into the pipe, after you add a layer of gravel cover that with landscape cloth before adding the remaining dirt and gravel.

5. Grade slopes minimum 6” down within ten feet.

Here's pictures from our lovely but hard working weekend:
Make sure you read the captions, it explains more what is going on in each picture:


And more detail on site work:

Explanation of what the heck he's doing.

I busied myself on the interior of the prefab house kit, using an exacto knife (and fondly remembering my art school days) to slice off the foam we added around the window and door frames to further seal the house kit and aid its energy efficiency.

All these little things you do when under construction to add to the air tightness and energy efficiency of your home really will add up to long term savings and success!

In getting the gravel for the site work around the prefab house kit, we had a quarter of the load dumped near the prefab and used the rest of the load to be dumped along the trail we have driven over the fields.
So now, after YEARS, we have a road.
We are VERY excited - it's kind of like Follow The Yellow Brick Road except it's the Magic Gravel Road, OUR Road, leading to the off grid net zero passive solar prefab!
Yay.

We have a ROAD! And it leads to a modern prefab house kit!

Well, we're now back in Richmond, happy and sore and the dogs are plumb wore out and will sleep for days...

Last night we had a lovely, LOVELY dinner with our friends Steve and Chris Ault, who have a natural farm down the road. (Check out some of the home made cheeses we ate for appetisers on the right, here!)

They took pity on my recent Sickness Postings  and not only fed us a *delicious* dinner with great company, in their cozy warm wood-stove heated home, but sent us home with a care package containing a young rooster, home made cheeses, and lard!

We are so grateful to have so many close friends here, it always makes the drive home so hard - you're happy from a weekend of hard work, feeling the sun on your face, happy exhaustion, the feeling of having "Gotten Things Done" - yet as your car drives, your heart saddens, you already miss the winter sun against the fields and trees and even though you return to a house with systems, with heat, it's just not the same as the crisp reality of being on the land, with good friends.

Over dinner, we pored through pictures of Steve and Chris's renovations to their farm house which they bought in very poor condition (see right picture here) and have restored themselves into a happy, beautiful home.

Fortunately, Steve and Chris were able to take this farmhouse and REBUILD it over ten years, from the foundation up, adding insulation, new windows, all kinds of structural work, and refabbing it to current standards. I'll go back and take some pictures of that renovated farm house soon - I didn't get an opportunity to do so last night.

We may still have no systems, but on the drive back to Richmond I thought about how so many people, especially in rural homes, are still in structures with no insulation. Driving home, we pass so many homes where generations of families live, in trailers or drafty 1800s farm houses and you know: there is NO insulation.

Our prefab house kit, even with no off grid systems yet installed, can get us through a winter - but think of the conditions of so many of these rural homes... even with no heat, our house kit only got down to 49 last night (it was in the 20s outside)... Under a down comforter, my bed was cozy and yes I will be happy when we have systems but... to go from 49 to 60ish with systems? Isn't such a strain. And to then maintain that temperature? Easy, because the prefab house kit is tight.  

Thanks to the structural insulated panels, passive solar design, and all the little extra things we, as house kit purchasers, do to accelerate its performance: foam around the windows, the door frames, and around and under the foundation, we should have a happy, warm home for (hopefully) generations to come.

 

Thinking About Your Prefab Green House Kit: Contractor Tips And Thoughts

We were hoping to head out to the prefab net zero energy green house kit this weekend, as we were snowed out last weekend... but check out the weather forecast, above.
I'm even hearing the words, "twelve to twenty inches" ominously, forebodingly whispered amongst colleagues when they speak about the upcoming weekend.

I am dying to see the interior walls that were built two weeks ago, yet there is still over a foot of snow on the land from LAST week!  Our carpenter, a Mennonite minister, is also leaving to move back to Haiti (where they lived for five years) to help their Haitian community in March, so I would really like to properly thank him in person before he goes... Danged this snow!

But good news: Ran the numbers last night - looks like our *own* prefab house kit we're building is still at around $100sf (actually less if it weren't for all the off grid stuff we're doing). Good to know you can be net zero off grid yet affordable!

Now we're in the final stages, and of course the systems will be very expensive to purchase and install, but you can see our own prefab zero energy green home tally here. Of course YOUR local material and labor costs and systems you choose will all be different. But this is what it's costing for us to build and complete the net zero off grid prefab house kit in rural Virginia as a net zero energy home, not tied to the grid.

But let's talk about you. A lot of you are in the process of permitting and getting ready to start foundation work. Here are some contractor tips I collected over the year to post during this long snowy week, information you might find helpful to think about when planning your own prefab green home.  Of course when you have the design documents and go over them with your contractor it will be easier to make your own choices for your own budget, but here are some "general contractor tips and things to think about."

I subscribe to the Good, Better, Best philosophy.

• Best would be if I could all hire an in-house team of my house kit SIPs specialists to erect and complete the house kit from start to finish, then certify it to LEED and passive and BREAM standards.
• Better would be where I choose a contractor with decades of SIPs experience to construct my house kit that was enthusiastic about off grid energy efficient homes.
• Good would be where I find a fantastic, reputable contractor willing to 1. educate themselves with the manufacturer's manuals, 2. attend workshops, and where I, as the consumer, 3. also educate myself on SIPs and green building technology to then feel confident I, with my contractor, was making the best choices I could for my budget. 

In our own net zero energy house kit construction, it is clear we are in the Good category as consumers of our own house kit... once the modern house kit was erected, you even see us change direction on the interior a bit...isn't that real life? We're adding built-ins to where there's designated closet space, expanding that area to accommodate off grid systems and our own funky, bookcase lovin' lifestyle.

Many people ask why I don't just ship out a completely completed prefab house kit. Here's WHY I'm offering the house kits the way we do: My mission is to offer energy efficient house kits that are gorgeous but also affordable... attainable green design.

By having you order your windows and doors locally (we send you a list along with the design documents), you can then order them at a more affordable price than if we had to add them to your house kit shipment (adding to the cost of the windows the cost to store them at the factory), increasing the truck load weight and number of trucks, increasing shipping, increasing risk of damage and increasing cost.  

By leaving the house kit unfinished, I give you control: you choose your systems, your finishes, your appliances to your individual needs.

• We CAN have the house kits finished more if you like, which we are working on with European clients. But it will cost a lot more; more than if you worked with a local contractor and supply store. But we certainly can include the windows, doors, framing in shipping containers.
• We do have contractor firms we recommend who WILL travel and complete the kit for you, and are familiar with SIPs and our house kits, but it will cost a lot more. Just ask, I will send you names.

Now on to Contractor / Construction Tips And Thoughts!

• ERV / HRV: Because of the energy efficient, tight structural insulated panels in the prefab green home, you will want to make sure you choose an appropriate heat / energy recovery ventilator that works for your area climate needs. We recommend two manufacturers and are happy to send you their contact information.
  
• Roof panels: Do you want chassis ways or will you use a surface-wired mold? If you like, you may tell the factory where you want to run a roof chassis.
• It's not just about the house kit: Are you keeping in consideration How To Keep Water Away From The Foundation?
• Another tip: Copper pipes and galvanized duct work: Do not let them come into contact! They will deteriorate, then leak!
• Framing: Your contractor will need to build anything that is not structural insulated panels. SIPs are the majority of the house kit, but there are areas (note along north and clerestory windows) that the engineer deemed it structurally better to have framed in. This is dependent on which house kit you choose. FOR THE CASA TI, here is what *our* contractor estimated:
  
  "Here is the estimated list of wood required to assemble the SIPs:
  
  Dim Length Qty
  2X6 8' 60
  2X6 10' 48
  2X6 12' 13
  2X6 14' 4
  2X6 16' 7
  2X8 8' 31
  2X8 10' 42
  2X8 12' 22
  
  
  
  
  
  Headers:
  
  5' 3 5/8 header 9 1/4 "
  16' 2 1/4 header 10 1/4 "
  3' 6 3/8 header 11 1/4 "
  3' 1 7/8 header 9" tall, design/measure on site
  2' 9 3/4 header 11 1/4"
  2' 9 5/8 header 11 1/4"
  2' 9 3/4 header 11 1/4"
  8' 8 1/4 header 2x6, wall thickness?
  8' 8 1/4 header 2x6, wall thickness?
  5' 9 header 2x6, wall thickness?
  2' 9 3/4 header 11 1/4"
  2' 9 5/8 header 11 1/4"
  2' 11 1/4 header 11 1/4"
  2' 6 3/4 header 9" tall, design/measure on site
  12' 3 header 2x6, design on site
  12' 3 header 2x6, design on site
  
  The following is not included in the above:
  
  - framing materials for interior load bearing wall/header
  - framing for panel H (row of small windows at transition of roofs)
  - framing for edge of parapet on north end of roof
  - framing between walls and roof
  
  
• Filing this under, "Things your contractor should know":
  Obviously, make sure your contractor carefully READS THE SIP MANUFACTURER'S MANUAL...
  Because there is a *lot* of useful, critical information in there that is imperative to the success of your project. We also have workshops and schools we can point them to, and the factory is always ready to answer questions.
  
  But even if they follow successfully the SIP instructions perfectly, even if they're the *best* contractor, ever, don't forget they might have aesthetic differences than your love of modern design, so here are just some easy things you can point out/gently remind them...
  
  
• Modern Design vs. Traditional Trim: The trim around the windows should be narrow- It should be “receiver trim” that catches the end of the cut siding.
  
  It's a very minimalist / modern look, not a traditional way of trim- not 3” wide but more ½ inch, flat, for corners and openings- see this as an example: http://www.daviddaydesign.net/horsepen.htm
  And this:
  
  
• MAKE SURE before you order cladding where everything is measured out individually by your contractor, despite what the plans say.
  
  Why? Because there are materials and decisions your engineer / contractor will make on site that might slightly change the dimensions- like adjusting the pitch of the roof or framing an overhang out more to accommodate the sun in your area.
• If you're building a casa ti and using a rubber membrane on the north roof, we randomly came across a graphic that explained the parapet and scupper concept really well! Don't say we're not geeks!
  
  Flashing ("scupper") in the passages through the parapet BEFORE the rubber membrane is installed:
  
• Cladding: Consider HardiePlank, cedar, galvalume (we can put you in touch with the manufacturer we used but make sure you also get a local quote), and I have one other solution that I will post more on in the next week... but cladding is totally up to you! Be creative!
  
• Roof: Consider using white paint to reduce heat reflection.  We discovered a great paint application that increases energy efficiency, more on that soon!
• The West Door: YES it is supposed to be painted black to line up with the window above it, I will do so as soon as I have time... : )

 

Passive Solar Prefab House Kit: Touching on ERV / HRV, Fireplaces And Dessicant Wheels

If you're wondering, we have no intention of having our own passive solar prefab house kit certified. That's not to say we're not mentally aiming for passive house / similarly efficient standards, so a lot of passive house information I link to regarding our off grid house kit systems is because it is designed for highly insulated, tight homes like our own prefab house kits.

You know our house kits are energy efficient, being built with SIPs (structural insulated panels), passive solar, and designed by LEED accredited architects. That is not to dissuade you from certifying your own house kit- there is much value in how far you can take this bare-boned house kit architecture- pushing it as far as you want in energy efficiency and off grid / net zero energy systems, with the help of an accredited certifier.

A tight, energy efficient passive solar house kit built with SIPs also means you are going to need a way to mechanically exchange air, preferably without losing / gaining temperature from the outside, as well as ensuring moisture does not sit within the house kit.

Talk to your contractor about what works for your area and for your own needs, but here are some links I found educational:

• Good overview of a desiccant wheel and how it works / differentiates from an energy recovery unit.
  
  
• Here's a good overview of geographical areas where you determine whether to use an energy recovery unit or heat recovery unit. (We will get into this in more detail in an upcoming systems post...)
  
  
• FYI: At the 2005 solar decathlon, Cornell used a desiccant wheel in their house, which was the only home to meet the required humidity levels during the competition. Here's what Cornell used: Outdoor: Trane XL19i Indoor: Trane 4TEE3F31A Split-system HP w/ RotorSource desiccant wheel 2.5 ton Ducted forced air
  
  
• And finally: Fireplaces in a passive house:
  
  
  
  • http://www.passivehouse.org.nz/?id=newsmanager&s=passive&news=a3838f1ffe&lang=en
    
  • http://www.passivehouse.us/bulletinBoard/viewtopic.php?f=6&t=28&p=153
    
  • http://www.leonardo-energy.org/drupal/node/1275
    
  
  

Any-hoo, we are currently trying to figure out if the mid-century fireplace is worth the effort / expense; whether it is worth adversely affecting the house kit tightness to integrate into our prefab house kit when we could spend that money towards systems. 

We originally spec'd the systems plan to not have a fire place- coupled with radiant heat, an efficient stove would easily overheat the net zero energy house kit.  But when it got down to eleven degrees and we were still without our off grid systems installed, I went a little crazy.  Handsome Husband knew the disadvantages the entire time; I did too, intellectually; but try explaining that to the frantic-mom-inside-of-me-trying-to-resolve-warmth-immediately.

Regardless, the coolio modern fire place will be put to use, even if as just an outdoor feature... but that doesn't help us when we haven't installed systems and need heat immediately... it's a shame if we can't incorporate it, now that it's there.

From Handsome Husband:

"We started with our desire to be warm, not yet having purchased and hooked up our systems. Getting the (admittedly cool) fireplace led to the realization that a ERV would need to go hand-in-hand with such an installation (or anything), coupled with the need for a fireplace / stove in such an efficient house to prevent back draft. Many people now realize that burning a fire in a fireplace in a traditional home has the following effect: the flu sucks air out of your home in a big time because, boy, does heat rise and air gets shot out of your flu.

Well, that creates negative pressure in your house - air is sucked out of the house. In a conventional home you get new air sucked in through the cracks in your house to maintain balance of pressure with the outside. In a home built with SIPs the envelope is much more uniform and easy to seal- you do that, of course, and end up with a home that doesn't have cracks to suck in enough air to balance the loss of air through the flue. What happens next apparently is that the negative pressure in the house exceeds the power of the air rushing through the flue. Bad news because now the smoke from your fire no longer wants to go up the flue but instead becomes the means to de-pressurize the house, compensating for the previous loss of pressure.

What to do?

Sounds like one wants to prevent de-pressurization. This occurs when air is sucked out of the house - something we don't want anyway because we just HEATED that air. So you decouple the flue from the house by giving it its own snorkel - sucking air for combustion in from the OUTSIDE through a tube running from an outside wall to the inlet on the fireplace.

This works great for SEALED fireplaces or wood stoves or, of course, pellet stoves. In our case we have the mod version of a chiminea and we have to see whether we can a) attach an external air supply to it and b) seal the fire place by replacing the screen with a sealed cover.

Fall back is to use it seasonally by swapping it with a sealed wood or pellet stove with external air supply."

In the meantime, here are some video updates on the modern prefab passive solar green home:

Still sorting VMI floorboards to reuse in the passive solar house kit...

Note to energy enthusiasts: He also discovered there was a pipe that had not been correctly sealed during the energy audit... which certainly contributed to temperature drop / leakage... that is now corrected!

Net Zero Energy Passive Solar House Kit Update

...An unexpected visitor to the net zero energy prefab modern house kit:
(Dude, don't eat mah steps!)

Handsome Husband Encounters His First Hog


Now, now. I know we've been persnickety as of late, but don't think we're soured and nasty over all the recent heating hullabaloo...
Despite the prefab zero energy house kit setbacks, we keep on tha' sunny side! (Right June?)

 

Prefab Green Home: 1st Energy Audit Of The SIPs House Kit!

This is the FIRST of two energy audits.

Energy Audit #1, today's energy audit of the prefab modern house, is as we're at the "This is the modern house kit + cladding + the homeowner sealing around the windows stage", the second will be once we're "done, finished, kaput, as in done, done, done, done, don't ever want to think about anything construction related for at least another week DONE."


Our mission is to create tight, energy efficient, gorgeous passive solar house kits.  I admire rated, certified, even more stringent approaches, like Passive House standards, maybe we'll do this in the future, but we achieve what we want in an energy efficient home while incorporating great modern design on an average, reasonable budget.

Some highly energy efficient homes incorporate two door chambers to prevent temperature loss.
I picture the way I live, and it is just too chaotic and messy to make such an entrance successful.  Can you imagine a couple struggling with the stroller, dogs still on the leash, juggling a bag of groceries and a baby on one hip, getting the key in the door lock then screaming to the spouse...
"Quick honey, seal the chamber, we're losing LEED points!"
Obviously if you live in a severe climate, it makes sense. But we're in Normal Rest-o'-Tha-World here.

We're a muddy, raggedy bunch here... why do ya think we're bandits?
You can increase the thickness of the house kit panels, choose even more efficient doors and windows (our casa ti prefab green home is spec'd for Jeld-Wen and our, SIPs house kit with two stories, The R1 Residential, is spec'd for Marvin Integrity), seal it up even tighter... but my focus is on affordable energy efficiency in our prefab green homes, so we chose great solutions that fit within a moderate budget.

The average quote for the casa ti windows is currently about $9,000-$10,500. If you would like to spend more on windows to make 'em nano-crazy-efficient, go for it, we can adjust the shop drawings. But expect the added cost.

We hired energy rater Guy DuBois, of No Energy Loss, to come out and inspect the modern prefab house kit. 
These are the notes I jotted down during his cell phone call to me en route from the land. Mr. DuBois will guest blog later this week with more real data, but here are his initial verbal impressions of the still-under-construction, still-not-completely-sealed house kit:

"Well, we certainly smoked up your house quite a bit, there was nowhere for it to go!"

(Copeland's note: Ummmm, I assume he means it was some kind of smoke air test thingy? I hope he didn't mean he smoked in mah house?!?)

Ok, on to Mr. DuBois:

"Those windows - they are worth the money, they were very well sealed."

Copeland's note: Handsome Husband also sealed around the frames... OK FINE I will just stop commenting and just TYPE what he said!

"Your husband did a good job of sealing around the windows... there are two areas he also could look at if he wanted to seal further- along the south eave and that back door threshold.

It is surprisingly tight. I don't know why I say surprising, but I guess I didn't expect it to be so tight, even though I should have."

[Copeland's note: Um, yeah, thanks Mr. DuBois... ; ) OK, OK I'll stop commenting!]

"I'll go back at completion and run more tests.  This was a good time to go out there because if there were problems you could address them before everything was closed up.

As you know, it's so tight you really must have mechanical ventilation, which you will be installing (HRV), which is critical in these energy efficient homes. Most homes, most traditionally-built homes, leak willy-nilly so you don't ever have to worry about air quality, but in energy efficient homes like these they're so air-tight that air-exchange is imperative.

I saw very little air leakage... there is some thermal bridging you can address if you want but you certainly won't have a problem heating and maintaining good energy efficiency, that's for sure. How does it compare to a "normal" house? Superior!"

To continue to seal even further, concentrate on the areas where there is lumber vs. SIP (structural insulated panels)- the doorway header, add insulation around wooden framing, and if you're in really severe climates, you could add an exterior seal.

Mr. DuBois makes a good point:

"But you have to consider the climate- maybe if you're in Alaska or really south Florida you would want to consider that, but... we're in Virginia, how much gain will you really get by doing all that?!? You already know that with your off grid systems, comfort will never be an issue.

I will be punching in everything I did today and coming back with some data next week... you're not trying to get this house certified, so this is just more FYI info, but it will be cool to compare today with when you're done at the end of the project."

He also said that the amount of leakage currently (we're still not done sealing) in the prefab SIPs passive solar home is equivalent to about 6 x 6 inches, smaller than a basketball. Handsome Husband is chasing that number, with sealant in hand.


Later, Handsome Husband arrived home, and I had all these pictures and video to look at... and share with you now.

HOUSE KIT ENERGY AUDIT VIDEOS:
Mr. DuBois sets up...

SIPs House Kit Energy Audit #1 of 2

They start do to the smoke test and pressurize the modern house kit. SUDDENLY, a clerestory window pops wide open!  It had looked closed, but hadn't been closed totally, which certainly that had also contributed to our loss of temperature this winter at night!  It is securely locked now... : )

Smoke And Open Windows In The Affordable Prefab SIPs House

So, they pressurize again...

Energy-Audit-#1 of 2 In The Affordable Prefab Green Home

And then....they freakin' fill mah house up with SMOKE!
Note the comment about the south edge- later they discovered that when the door was installed they didn't put any sealant under that south door.  You as a home owner can seal that more if you live in a severe climate area. I knew the windows worked really well for our budget, but am pleased with how impressed he is! : )

Energy Audit 1 of 2: Smoke And Windows

Here Handsome Husband decides he's going to track down that durned elusive number.


Energy Audit 1 of 2: Husband Wants Passive Perfect

Then they go tramp around outside looking for leaks.
If there were gaps, you'd see the smoke drifting out.

Energy Audit #1 of 2 of the Prefab Net Zero Energy Green House

Check out what it looks like when they crack the door (and how hard it was to open because of the pressurization - because the house kit was so tight!).

Energy-Audit-Of-Green-House-Kit

...And then they start calculating...
Which Mr. DuBois will go into more in his guest post soon.

Energy-Audit-01-16-2010-36 from Copeland Casati on Vimeo.

And thaz it, the latest from our passive solar green home!

Here is Handsome Husband's summary:

"This wraps up the initial test of the house kit. We now know what simple steps we have left to optimize the envelope of the SIPs house, and we look forward to the final testing after construction is (finally) completed. The general goal and idea of the casa ti has passed Mr. DuBois's testing with flying colors, as we already suspected in the prefab house kit's performance over the last few weekends where the design and structure were able to give us relative comfort in a hostile climate.

The great thing about the delays in this project is that we're able to thoroughly test the house kit without further improvements, this allows us to confirm the performance a passive solar house kit built with SIPs."

 

The Insulation Post: Outside The Prefab Net Zero House, It Plummeted To Eleven. Eleven Degrees.

It plummeted to eleven degrees outside the net zero prefab SIP house last night.

And we're on a windy hill so... I... I just can't imagine what it was. I don't want to, honestly, as we still have not installed our off grid systems that would ordinarily keep us comfortable during these frigid temperatures.
Even with the kit house built of structural insulated panels, there is more you can do as a consumer to insulate and make your own house kit more tight... I encourage you to do so.
(And you will really appreciate those extra efficient touches in this weather!)

I previously mentioned how you can also order foam from the factory to put UNDER and AROUND your foundation:

"Insulating your home is not just about the SIPs panels that come with our Green Modern Kits SIPs house kit.

As the weather turns cooler, think of being outside on a frosty day:
Bundled up with a hat, scarf, nice warm coat... and...

No shoes? Bare legs?!?
Think of the exposed skin losing heat as it gets sucked away in the wind and cold...

Your house is like that too- despite the SIP insulating properties to ensure your home is tight, don't forget to add insulating foam underneath (and around) the foundation!"

We will start wrapping the exterior foam around the foundation next (we already added it below the foundation before we poured the concrete), but first we are sealing around the doors and windows (vs. paying someone to do so).

Each of Green Modern Kits / Green Cottage Kits / Green Cabin Kits' prefab house kits are different, and on this passive solar net zero casa ti there are a few areas that your contractor builds in that were too narrow for a SIP: obviously around windows and doors (to leave room for  framing); but on the north windows there is some higher framing to connect the SIP panels above the window, and between each clerestory window.

(Reference this picture, above - the vertical white to the right window Handsome Husband has just added foam to, and is now measuring between the next clerestory to cut his next piece of foam to add and therefore insulate between the windows that are not SIP. You / your contractor may choose to insulate there another way if you prefer.)

Sealing The House Kit Further:
Adding Foam Between Clerestory Windows

Still without systems, the net zero prefab house has been amazingly comfortable throughout the seasons... until now.
In Virginia, these extreme teen temperatures are not encountered often.  Until our off grid systems are installed, we are now relying on portable temporary heat to help the passive solar house kit maintain a comfortable level once the sun goes down and the temperatures plummet to such an extreme. 

We arrived mid-day Saturday to the interior of the prefab house kit reading 50. Outside, it was in the 20's. (The high was 28. And it was windy - gusts of 30mph. Mmmmmmmmmmmm, niiiice.)

Regardless of having no systems yet installed, having the energy efficient shelter of the prefab house kit shell has enabled our family to be on the land in January for the first time ever. Before, we would wait out mid-December through March... and only imagine what the land and community was like during that time. We are grateful to be there now even in these frosty conditions, and excited to see how cozy it will be once we hook up the solar / radiant heat / rainwater collection / etc.!

We met with Mr. H., the carpenter who will be building the interior walls now that Ron is retired.  When I explained our desire to not use dry wall and that we will instead reuse VMI's basketball court where possible, then that the house is off grid, then our general "pay as you go" philosophy and ended with,
"Maybe we're The Crazy Family in the area..."

He responded assuredly, "I always say, 'The customer is always right.' "
[Waaaaaaaaaait a second!
; ) ]

We also have news on the wood stove issue:
The one we purchased was not certified for residential homes but a garage and so it was returned. 

Dejected (and knowing there is a perfectly good unused residential wood stove sitting in my parent's basement three minutes away from our house in Richmond that has now been promised to my dear brother who lives on the border of South Carolina... here I will end those mentions... just remember we were with our children in eleven degrees this weekend...), after spending the week making phone calls in a rural area trying to get someone (anyone?) to install my now imaginary wood stove... the phone rang.

"Hey. I hear y'all are having some issues with heat."

Early in my life, I learned a valuable lesson: Be a good friend, have good friends.
My. Friends. Are. Awesome.

Shawn Stanley offered up a cool, mod fireplace (still making those phone calls about installation).
We dragged it out to the prefab house kit and daaaaaaaaaanged if it didn't look perfect inside.
(Note: I am still looking for an installer. What is great about this fireplace is not just the coolio design aspect but that a conventional regular-sized wood stove would easily overheat the efficient, small footprint house once the radiant heat, etc. is working! Keep your fingers crossed. We shall see.)
[Should I insert ominous laughter now or be positive? I will do both. : ) ]

Regardless, with the portable heat we turned on after dark we were able, without systems, in freakin' dire temperatures, to get the house from it's natural passive solar 54 at dusk to 63. With a 15,000 btu heater. Outside at dusk it was... 20ish? (High was 28 that day. And at dusk it plummeted outdoors to 10, 11ish degrees.)

When we awoke, we could see our breath: it was 49 degrees.
At first, losing that much in one evening (about 1 degree per hour) shocked us.
Until we saw what the outside temperature had become.
With no systems installed. 
And not finished insulating the crevices.
Handsome Husband makes a good point: "Inside, it's uncomfortable. But what this proves is that you can survive, without systems, without freezing, in dire conditions. Outside? You're dead."
Ok, ok, but what about art?

So... I warmed up, drank some coffee... and then... I hung some art.
It's crooked.
That's ok. I'm also leaving it in the plastic it arrived in from the framing shop.

Y'know, (scoffs) 'cause at least I know that we're in a construction zone. ; )


(Contractors take a look at 0:45 and 1:20ish in this clip...)

To further vex Handsome Husband, I hung some old cuckoo clocks. They turned out to unexpectedly work. Which... shockingly... thrilled him!

[Cuckoo ... we are...]

I tried to throw a clean sheet over the Danish day bed to give it a crisp modern look, but somehow all the dogs and chillunz associated it immediately with "A Great Place To Nap And Jump!"

With the southern sunbeams shining invitingly directly on the frickin' day bed, I can't say I blame 'em...

Really, it took me about 24 hours of repeatedly re-attempting crisp hospital corners and re-smoothing it until I finally realized how futile it was and gave up.


Here, I finally hung some art as well, solidifying the reading corner (where you can then stretch out in the sun on that day bed to read)... and leaving the art in the pouches it arrived in to protect it from construction dust.

It's rewarding to be out there despite the cold, alternating relaxing with progressing on the prefab house kit even before the professionals return to finish the next phase of the net zero prefab green home.

In about two weeks the interior walls will begin to be built (yet leaving one side open so the electrician and plumber have access without having to redo anything).

In the meantime I am calling and calling around trying to find someone to come speak to us about installing the modern fireplace in the energy efficient green home (an issue, as a SIPs house has some considerations - as always, air exchange and proper ventilation are important...).  But that fireplace, if installed, will provide good heat as back up, yet without over heating the energy efficient and tight house kit.

Really, I just want to be hot and cozy even without systems installed... is that too much to ask when temperatures are in the teens? ; )

...Stay Tuned. We'll be out again this week in the net zero prefab green home... still with no systems!

 

Prefab Green Home Systems Post #1 For A Net Zero Off Grid Modern House Kit!

In Virginia it is 22 degrees. Handsome Husband is off cavorting in Florida (Ok, fine, it's work, but *I'm* stuck with the chilluns, dawgs, chickens, fish, and feral cat!), so I will not be visiting the net zero off grid prefab green home this weekend as the logistics to do so alone are overwhelming.

So here come the net zero off grid prefab systems posts, guest written by Handsome Husband: Part One: Rain Water Systems.

**NOTE*: *OUR* systems choices are so minimal and bare bones, you will almost certainly want to consider the more robust packages our partners offer. But our focus as a family is to do as much as possible with as little as possible.**

"I will post our system choices for the casa ti prefab over the next few days. Every post will focus on a subject, beginning with how we plan on supplying the casa ti with water.

We will use rain water collection as the water source. In our area in central Virginia we receive sufficient annual precipitation to easily provide water for a 4 person house hold without having to dig a well. Rainwater collection begins with the choice of roofing materials. Asphalt shingles are not the material of choice as new shingles could leach petroleum products and contaminate the rain water - we chose a metal roof on the southern side of the house for this reason. The northern half of the roof is wrapped in a rubber membrane as a basis for the green roof (vegetation that is as everything seems to carry the term "green" these days). Rainwater from the vegetated roof area should not be used for potable uses but can be used for irrigation and other non potable needs.

We will use a WISY WFF 100 as the primary rainwater filter. This filter receives the rainwater from the downspouts, and separates debris from the water routed to the cistern. We will need to design the downspouts so that they all merge into this single filter. http://www.rainwatermanagement.com/product.php

Next comes the cistern. The first choice is between an above-ground cistern and one that is buried. We are considering going in between in that we would place the cistern in the root cellar. Root cellars are semi-buried structures that enjoy some of the same benefits as geothermal heating: In the winter the stay above freezing and in the summer they don't heat up as much as the ambient temperature. The same will be true for our water!

We plan on using a 1500 gallon polytank intended for freshwater storage (http://www.watertanks.com/products/0005-028.asp).

Now that we have collected, filtered and stored the water we need to pump it into the house. We will extract the best quality of water from the tank which is just below the surface using a floating inlet filter. This type of filter is connected to a floating ball and collects water 4 " below the water surface and comes with 8' of hose to connect to the pump http://www.rainwatermanagement.com/product.php.

Next we will install whole house sediment filter. Given the design of the inlet filter I don't expect this filter to collect much of anything but hey, these filters are relatively cheap and collect objects down to 1 micron. (http://www.purewaterforless.com/site/675488/product/PE-SPF-34)

There is some debate about the need for UV light as an additional purification method. We will have the water quality tested once the system is installed and will see, whether this will be necessary in our application. Until then we will bring bottled water and just cook/shower with water collected from the sky. As with any water system, it is important to have the water tested for water quality. Additional filtration may be necessary once the system is installed and tested. Any water system including wells should be tested at least annually to ensure the water quality remains at the highest level for human consumption.

That's it for this first systems post for the net zero SIPs passive solar prefab, casa ti! Our next post will describe our approach for heating the water (DHW)."

There you have it, straight from the Handsome Husband's mouth.
Now if only he'd only hurry home so I can take a break!
We will be visiting the prefab next weekend as we have a meeting with our Fabulous Contractor regarding our next steps for the net zero prefab green home.