Proper design of fenestration to eave overhang ratio will address some, if not all of this. You can also consider a greenhouse for you solar collection that can be isolated from the main living structure.
I have no idea how to address cooling in the summer other then to introduce an air conditioner somehow into the system so any ideas on this would be greatly appreciated.
I will probably will not be of much help to you as it sounds like you are going for the "technical-industrial" side of "green" architecture. Remember, the more technology you have the more you have to break down, and that is electricity dependent. Personally I would recommend some style of pièce sur pièce, Post-and-plank, timber frame, or combination there of.
-For heating I'm thinking of using solar thermal hot water heating panels on the roof with a solar electric system to pump the water. I think we will have to use a large stratified water tank to store the heat energy and rely on a high efficiency HRV system to control heat loss with our air changes.
If you have the hose dependant on Technology, you have to think electricity and back up systems for it. Design without these constraints and you will not have these issues. The home should be designed to function perfectly well without tech, then what tech you use is simply a convenience, not a dependance.
-The house wont be off grid but I don't want to rely on the grid for any of the climate control demands of the house.
You could bring it in from the outside directly to the fire box like on many wood stoves, though if the home is design to be draft proof, but permeable (breathable), you probably don't need to worry about it.
Here is one of my key questions, I'm really liking the rocket mass heaters as a secondary heat source for the cold winter months however because its going to be a passive house how do I manage the air changes necessary to feed the mass heater with air?
Not if you get the home design properly, though a methane or propane system for cooking would not be a bad thing.
Should I look at another secondary heat option?
I would argue that the technology of RMH is more complex than the technology of HRVs even though HRVs use electricity. HRVs are simply fans with dumb heat exchangers. They may be described as "technical industrial" but they are a much less risky technology than any combustion appliance. The desire to simplify is behind my advice to avoid solar thermal radiant floors.
HRVs work best when they have balanced airflows which can be hard enough as it is. Introducing an RMH to the equation upsets the balance and puts smoke, moisture, particulate and probably overly hot air into a technology not designed for it. Make up air supply ducts are relatively easy to make airtight.
Many people feel that the make up air should not be directly attached to the combustion appliance and be supplied in its general vicinity for fire concerns (backdrafting embers).
Al's statement about "thousands" of SIPs home failures is a gross exaggeration in my opinion. Maybe hundreds, but even that is a stretch and most of those failures are from poorly executed details like not sealing between the panels. Air leaks cause rot on SIPS AND conventional homes. SIPS homes are generally much more airtight than most construction.
Now for the nitpick.. I dont think every home requires an HRV but I do feel every new home should be built tight enough to require mechanical ventilation. This might fall into the nitpick zone or it might be a fundamental difference between natural focused builders and more high performance "modern" builders.
I think most natural builders see the benefits of mechanical ventilation and are beginning to include it.
I fail to see the difference between "airtight" and "draft proof". If a home is not getting fresh air from outside then the air inside is not as healthy as it could be.
The current debate between Indoor Air Quality experts and building scientists is how much CFM of outdoor air introduction is ideal.
A "draft proof" home with no mechanical ventilation has no control over the situation other than opening windows which works great sometimes but not all the times.
As for SIPS, I agree that they can cause problems. I disagree that problems you may have encountered were products and installations done appropriately. Either the manufacturer screwed up or the installer did.
From my experience people have been more comfortable in their SIP homes and like them so much they insist on doing them again (even when I try to talk them out of it).
I also disagree that they are good for a contractors profit margin as they are usually not. Contractors avoid them because they are different. I don't think SIPs installers or GCs specializing in them are getting rich and usually it seems they are making less because they are passionate about energy use to the point of losing money.
Your point about accessibility is fair but I would argue that in ways this is a good thing. Look at Bensonwood's open built model for the ultimate accessibility, even more than conventional construction. http://bensonwood.com/innovation/index.cfm
Plumbing should be kept out of exterior walls anyways and as for wiring after the fact, keeping conduit to the interior and not opening up the exterior envelope is good for both SIPS and conventional walls. They typically offer more accessibility and flexibility than log and timber structures in my experience. Many cold climate builders work to keep all mechanicals inside the building envelope to avoid having it compromised by future inhabitants.
Oh and Sean, never install foam on the outside of SIPS. Maybe a more permeable insulation like Mineral wool but this complicates one of the best practices for SIPS; having a ventilated air space between them and the roofing or cladding.
Sorry if Brian and I detracted from your query or that you found no value in them, and pointless. "Best way," is relatively subjective depending on your architectural values, financial abilities and/or skill sets in design and constructing the architecture you desire. Since I have spent over 35 years examining, documenting and disassembling vintage architecture I would have to disagree that much of what our forebears did with the resources they had could be called "stupid practices," in any way. Perhaps misunderstood by the novice observer, or not applicable to current building modalities, but I would seldom if ever cal them stupid. I have seen very little actual long term improvement in the domestic housing market, other than from a corporate or highly technical perspective. The ability to last even a single century for many of these homes is going to be a major challenge.
I honestly find the debate in this thread is interesting but overall pointless. "Green Building" is great, I'm all for old ways and new ways. Honestly I'm mostly for the best ways. There is a ton of wisdom to the way things were done in the past and frankly a lot of Stupid practices as well. We have come a long way in the industry over the last 30 years but as always the problem is that one size does not fit all.
If profit does not bother you and you get what you want, then that is a good thing. Most of the clients that can afford my services, typically do not care about profits either, only getting a structure that meets their architectural needs, goals and desires. I also know alot of contractors and developers, and I would say they are anything but stupid and most are very wealthy from their style of development, though that is currently shifting rapidly as the consumer public demands more for their dollar spent, and will not tolerate some of the old GC practices of doing business. I provide my guidance here on Premies free of charge for those that may not be able to normally afford consultation fees, in some cases I even help in person. You are more than free to hire me and I will charge you for the work that I do, as I am sure Brian would as well.
I know a lot of contractors and none of them are getting stupid rich of anything they do, the market really determines pricing.
I thought my recommendations in my first entry to your post provided as specific an answer to the level of questions you had asked, sorry if I failed at that. To address them more specifically, you are going to have to choose one of the myriad of building systems you have shared an interest in and ask very specific questions about them, otherwise the best I can do is generic answers.
I'm totally sold on better buildings and am very keen to put my money where my mouth is with my own build. That said I could really use specific responses. If there is a better more home grown way to build anything I'm game.
Yes there are, and if you chose one that you are considering over others we can discuss it.
There are a ton of cool options for building.
The architecture our group facilitates should last much longer than just a hundred years, and considering that some of the frames we use are already 250 years old, 100 more is nothing. Good architecture that is well designed should last well over 500 years, and 1000 is not unreasonable. As for thing like EPS foam, there longevity past even 50 years is in question considering there many environmental pitfalls, EPS foam is what we used in the lab to raise carpenter ants, and I have seen more than my share of wall voids hollowed out of the material by the invasive "wee-beasties" that like to borrow through it.
Your typical house should stand for 100+ years and if your burning a ton of fuel be it wood, gas or electricity to keep the place warm the impact over 100 years is way more then the impact of EPS or some other foam insulation.
That would all depend on the design of the cob house and its facilitation, if you had the work force, time and/or money, you could build a very thermally efficient cob house, though I agree I would not generally recommend it for your region.
So in some climates further south, a cob house that relies on simple thermal mass to be comfortable would be an energy vacuum here in central Canada, plus the cold spots etc would make it really uncomfortable to live in.
You have now mentioned straw bale, kubbhus (cord wood), and a few others, all it would seem do not meet your needs do to the required wall thickness. I would have to disagree with you about the efficiency of thermal mass walls, which is the principle of log architecture. I have help build and visited many of these types of homes, as far north as nearing the Arctic circle, and if well built and facilitated, they present as very efficacious during the long winters. This is especially true if the designs are augmented with additional thermal insulation like a mineral wool, of straw bale/kubbus mass. You are going to have to either use super efficient (and expensive) foams or other modern materials to obtain a "net zero," or even super efficient passive house, if you do not want walls thicker that 400mm to 600mm.
Simply using thermal mass doesn't work in my climate, you get a nice summer place and an ugly winter place, most people have no idea what -50C with windchill is like on a building let alone a human body.
nick pine wrote:allen lumley writes:
>... have you seen the Kalwal and Lumira Aerogel window panels from> www.kalwal.com/aerogel.htm ?
They look expensive, with 22% solar transmission, compared to $1.30/ft^2 twinwall from my local greenhouse supplier (Nolt's Produce in Leola, PA.)