Easier to read: http://gettingfreshinthecountry.blogspot.com/2012/02/posted-to-forum-httpwww.html


Hey Guys,

 

I would love some help from all of you knowledgeable people on this forum. I have a new house building project coming up in! May! and am poorly prepped at this time. I would very much like to get your opinions, tips, tricks and past experiences for this project. 

 

Zero Energy Home in MA: http://www.builditsolar.com/Projects/SolarHomes/MAZeroEnergy/MAZeroEnergy.htm

 

The Zero Energy Home is what was / is my goal but with some obvious alternatives as I am not building a stick frame house. I would like to get as close as possible to this example as possible within my budget. It is my goal. I understand certain things I can do exactly the same and others I will not be doing at all or choosing alternatives. 

 

Please find all relative details below: 

 

This is the current basic plan

 

1. Log Homes: We have purchased 2 x Pioneer Hewn Log Homes. Both cabins are currently shells. One is 24.5 x 28.5(698.sqft) and 25.0 x 20.0(500sqft).  They are both one and a half storey buildings. We are going to put them next to each other saddlebag style (google images for reference)

 

2. Foundation: 4' Deep Frost Wall. 6" XPS beneath the pads and inside of the pads on ground side. Flyash concrete for added strength and recycling a waste product.

 

FQ1: What is the standard depth of pads?

 

FQ2: What is the standard width of foundations? 8"?

 

FQ3: Who marks out the foundations for the foundations guy 

 

to dig, do they just work from the blueprints?

 

3. Radiant Heat Flooring: Throughout the two concrete pads. The initial idea was A) Earthtubes with water to preheat water pulled from the well to 55F then to run it through a B) Closed-Loop Drainback System because of the location of our home (Zone 5a) and lastly top it up to temperature with C) Polar Outdoor Furnace http://www.noutilitybills.com/OutdoorFurnace/Wood/PFLarge.html.  

 

For the solar hot water I am planning on doing something like the 2K DSW system from here:  

 

http://www.builditsolar.com/Experimental/PEXColDHW/Overview.htm  & http://www.builditsolar.com/Projects/SpaceHeating/DHWplusSpace/Main.htm 

 

HQ1: Can someone decipher or explain to me how I calculate heating degree days and cooling degree days for my location from this data? 

 

Local Weather Information: http://www.theweathernetwork.com/statistics/degreedays/cl6119511/caon0408

 

HQ2: What system would you recommend that is the most energy efficient (uses least power to generate heat) out of the following systems for my Zone 5A home location? 

 

http://homepower.com/basics/hotwater/

 

I am planning on the following system but would love to hear feedback: 

 

http://www.builditsolar.com/Experimental/PEXColDHW/Overview.htm  

 

& 

 

http://www.builditsolar.com/Projects/SpaceHeating/DHWplusSpace/Main.htm 

 

HQ3: I am thinking of going with this company as far as plans for the flooring as they seem very DIY and will help you every step of the way, do you guys have any thoughts / opinions? 

 

http://www.radiantec.com/index.php

 

4. Electrical: Tips / Tricks / Opinions for the most efficient applicances / bulbs etc. Standard wiring etc would love to hear any good cost effective ways to wire the house and any energy saving cost efficient ideas for this. Thanks. For electrical I would love to incorporate some solar with those companies that put the panels up on the roof and then pay you for the electricity such as Pure Energies (http://www.pure-energies.com/). I am hoping to do this primarily and then add more privately paid for later. I am also wanting to be grid tied at this point. 

 

5. Insulation: Walls: The logs are 12" x 8". They are going to be exterior chinked with regular mortar, limestone and sharp sand, wire then big stuff / spray foam in the middle then the same chinking applied to the interior. At this point we are not performing any more insulation on the interior as we would like 

to weather it a year to see how the logs perform. Apparently there is no good information on the internet how to insulate on the inside because of dew etc. I have found that even the "pro's" aren't exactly sure on this. From my research if I wanted to do someting it would basically be floating studs and then interior wall with Eco SPF. Roof: The roof, at this point I know that we are planning on installing a standing seam metal roof, reclaimed barn roof or shingled metal roofing. Again this has to come in within budget. I am unsure of the roof details at this point and how much room I have to play with. It will be a balance between space, material availability and cost.

 

6. Plumbing: PEX plastic tubing plumbing for the house. 

 

7. Septic: Standard Septic Tank for waste effluent. I am thinking of doing some kind of compost toilet system or using humanure to a degree if I can work it with little muss, fuss or smell for the Mrs. She is pretty adamant on using the ole water style toilets (obviously low flow with a balance between efficiency and cost).

8. Well: Standard Drilled well.

 

9. Driveway: I have been long hooked on the idea of a sturdy but grassy driveway such as these 

 

http://farm1.static.flickr.com/48/181275268_e231db5cdb.jpg?v=0

 

or

 

http://www.frankejames.com/art/buildgreen_500.jpg 

 

Again I am open to suggestions, another option is reclaimed asphalt.  Again as always cost to efficiency balance.

 

Other information:

 

I am basically going to be the General Contractor as I have the time to be able to run the build, now as far as experience, I need to rely on you guys, the intarweb and professionals who I will be hiring to do certain parts of the job such as:

 

* Solar Consultant - Recommendations for Ontario?

* Log Home Assembly - I have a team but need to clarify on details.

* Carpenters - I have a couple recommendations

* Electrician

* Plumber

* Driveway / Paver team

* Septic Tank Guy

* Well Guy

* Anything I'm missing?

* Foundations Team

* Roofing Team

* Insulation Team

 

I am very much wanting to do as much of this as possible and to sub contract myself out to each company / team. I would hire the electrician / plumber etc, have them tell me what to do i.e. grunt work like running pipe / wire and then have them do the certification parts and sign off on the work. I plan to do this for all of the build from the foundations to the roof. 

 

My father in law will also be accompanying me on the build who has subbed for his own stick frame house, rebuilt / reno'd another house and is a competent woodworker / handyman.I would love to hear all of your input in getting all the details organized and ready for launch in May.

 

I will update this post as I get more information. 

 

Thank you guys in advance, I have been reading your posts 

 

and feedback and value it much!

Can anyone tell me why this forum removes any formatting at all? No tabs / hard returns etc etc sigh. Enjoy the wall of text!

Edit: It was either Chrome or the adblocker I have in Chrome. I didn't see any of the rich text tools at all. Sigh

Have you tried editing it using a different browser (FireFox or Chrome or something)?  I can't read that wall of letters without getting seasick, give me some white-space for a horizon!


In general log homes are damn-near impossible to air-seal adequately, and seasonal dimensional changes can mess with your roof lines and ceiling air-seals even after they've been remediated & tested. The R-values of logs are funky too- in certain temperature zones they have more apparent-thermal-mass than others, but the average performance exceeds that of the steady-state ASTM C 518 R values due to these mass effects. (There are apparently natural phase-change materials at work in massive wood structures, but it varies with species and the climate where the trees grew.) The termite & ant issues can get pretty serious in some places too.

Got a location/postal code/nearest town? (For weather & climate data.)

"The requested URL /Projects/SolarHomes/MAZeroEnerg y/MAZeroEnergy.htm was not found on this server"

Sorry to be a wet blanket, but I agree with Dana1 - there are energy efficient homes and there are log homes - two different animals. One of the main issues is that wood moves - expands and contracts - continuously, so sealing it is very difficult. Will need to be done & redone at least annually. That said, probably the best way to make it tight is to build another house inside or outside - wherever you want to lose your "log cabin" look. Outside will be more efficient. inside, I'd suggest a minimum of 2" or spray foam then a stud wall with cellulose.

Thanks for the feedback Dana1, please see the original post - Now with ALL NEW FORMATTING!!! :P

The weather information you seek is listed under weather information in bold. Sorry previously Chrome was blocking the formatting tools.

The link for the Zero Home should work now. Please feel free to read the rest of the posts if you have feedback on any other of the parts.

From what I have read from the "The Classic Hewn-Log House: A Step-by-Step Guide to Building and Restoring" charles recommends just chinking and then the next year just adding some silicon sealant to top and bottom of the chinking. He has had much success with this and says that the chinking doesn't have to be redone many times over. I understand that the log home is a different animal altogether but that should not stop great people such as yourselves providing great advice ;)

Have you had many interactions with Hewn Log Homes Bob? Also I am looking for someone like yourself or some input on my build, as my goal is to use as much passive / solar input into this house as possible. I am hoping to minimize my costs to as close to zero and to come from renewable sources.

For the heating degree- days you add up the row next to "Below 18 °C (heating Degree days)

781 642 484 405 183 73 46 39 153 260 493 743

...which adds up to 4303 HDD, base 18C, unless I mis-keyed something. That's about 7700HDD base 65F, which would be on the very coldest side of US zone5, or the warm side of zone 6.

It's a pretty crummy location to get a lot out of solar heating. The money spend on a large active-array solar thermal array might better spent on a truly high-R air-tight building enclosure with well-considered passive solar designed-in (PassiveHouse style, if not necessarily PassiveHouse R-values.)

The 99th percentile outdoor design temps for Markdale is probably a few degrees cooler than Kitchener, or about -20C give or take which isn't terrible. If you are not on the gas-grid you can probably do pretty well with ductless mini-splits (or Daikin Altherma air-to-hydronic) heat pumps for lower cost heating options. Most Mistubishi H2i have specified 70% of the full-rated output at -13F (-25C), and most Daikins & some Fujistus specify the output at -4F (-20C) , but keep putting out something even at lower temps.

Using a website to design radiant heating systems is fraught with errors, and is likely to end up with something that costs too much or doesn't quite cut it. Solicit opinions on the radiant heating forum on this site- the guys posting as NRT.Rob and BadgerBoilerMN are both competent designers willing and able to advise reliably. But all good heating system designs start with a decent heat load calculation, and until you've settled on a house design it's all up in the air.

I'm not sure if Hot2000 has a log-home option, but it might. It's a freebie download that's pretty good at predicting energy use and peak loads for particular designs, if a bit bare-bones. DOE2 and BeOpt are also freebie downloads, but I'm not sure if they have weather datasets for your location (they may have data sets for a location in MI with a nearly identical climate & latitude though.)

The foundation footing widths etc depend on the loading of the house above, and the compressive strength of the foam below. Until you have a known design it'll be speculative. Most builders are using foam under the footings are using Type-II (or denser) EPS rather than XPS though. See also: http://www.greenbuildingadvisor.com/blogs/dept/musings/foam-under-footings.

In your climate a 10/20/40/60 rule of thumb for under-slab/foundation wall/above-grade exterior wall/attic R-values make long-term economic sense if it's done on a most-cost-effective-methods basis. (Similar to that MA Net-Zero house you linked to) Or you can use the values for zones 5 or 6 in table-2 p10 of this document:

http://www.buildingscience.com/documents/reports/rr-1005-building-america-high-r-value-high-performance-residential-buildings-all-climate-zones (note, those are "whole assembly" values, not center-cavity R in stud/rafter/joist bay, with the thermal bridging fully accounted for.)

To hit anywhere near those levels with a log structure it would be insanely thick (at ~ R1/inch). The mass-effect of an 8" thick log home allows it to perform comparably to 2x4 constrution w/R13 batts (R10 whole-wall R), but not much better. Building on Larsen trusses or an interior studwall to fatten out the R to at least R20 (whole wall) is advisable, and would make it easier to air-seal. But given the modest size, as long as you can air-seal it and put R40+ of cellulose in the attic you'd probably be able to heat it with a ~1.5-2-ton mini-split (or Daikin Altherma) even with the ~ R8 (R10) walls. (The MA Net-Zero house is heated with a 3/4 ton mini-split, but it's a much tighter & higher-R house than you'd be able to get without trussing-out the log homes for a lot more insulation value.)

I have many friends and acquaintances with log homes, and have done some remedial energy work on two of them. Most people I know who have them also use outdoor furnaces because of the huge energy consumption. One I worked on was new, built on a hill and was impossible to get over 50o on a windy winter day. The furnace was sized sufficient for a normal house, but obviously undersized for that log home. That one was 8x12 hewn square timbers. Very pretty, but impossible to heat. the other one we added roof insulation. In neither case were we able to make much of a dent in the efficiency, whereas we've had very good success with framed houses.

So they are difficult to make efficient, but that inherently means that we need to develop methods to do just that. Can you implement Dana1's ideas? You'll need to thoroughly insulate the basement and the attic, air seal the building, and verify the air tightness with a blower door. Easier done with building a second wall, but perhaps doable. What is the roof construction? Exposed beams or...? Some LHs have 2x rafters installed above the beam rafters, some use foam. How much latitude do you have?

My brother lives in a ~1500' log home with 12" timbers, a 4' crawlspace (with a 4" slab- a munchkin-basement if you will) in a climate with a heating outside design temp of about -7C but average winter temps of about +4C. Were it not for a strong back and virtually endless supply of windfall timber and a spouse with a professional technical job he'd probably go broke heating the place with the propane furnace. He has a high-efficiency woodstove, and an open wood shed that has total footprint of comparable area to that of the house (!).

To convert his place into anything close to Net-Zero would probably require air-sealing & insulating it on the exterior with 2" of closed cell foam continuous with a membrane roof) + 5" deep Larsen trusses w/cellulose under log-slab sidiing (if he wanted to preserve the look), and 6" of iso above the roof deck. He'd have to chainsaw the roof's round timber rafters an insert a thermal break there too, adding extenders for the overhangs outside the thermal break.

The charming stone chimney would either have to go, or get closed in with an insulating surround on the exterior too. The crawlspace is sufficently open & tall that he could retrofit 2" of XPS on the poured-concrete wall and atop the slab, and put a 2x4 batt mini-studwall against the XPS and either a rat-slab or OSB subfloor atop the floor XPS. At that point he probably would have sufficient south facing roof area to mount enough PV to get to net-zero with a 1-ton high efficiency mini-split as the primary heat source.

But for the time being he's happy to skid the big doug-firs & hemlocks that fall across the fire-road into his yard every time there's a big wind, and cut & split wood for entertainment, eh? ;-)

I love you guys... you are entertaining AND edumacating!

Would love some more input from others here with experience as well. Thanks much all so far.

Posted By neoborn on 01 Mar 2012 02:13 PM
I love you guys... you are entertaining AND edumacating!

Would love some more input from others here with experience as well. Thanks much all so far.

You will want to check out this website. Permachink far out performs any masonary type chinking.
http://www.permachink.com/
As mentioned above, to approach net zero in a log house is probably not doable. What style of log are these packages? Are the just round logs? or do they incorporate some type of tongue and grove system?
You might also check out wood gasification boilers rather then the inefficient outdoor furnaces.
Also if you are going to attached anything to the logs, remember that they will settle substantially. Allow room for an eight foot wall to settle at least 3" but the settlement is a result of species and cure. Green logs would settle more than twice this amount. You need to have this settling allowance over every door and window or the logs will crush the windows and jamb the doors. This space cannot be filled with spray foam, nothing more substantial than loose fibre insulation. Just another leaking place that needs serious detailing. If you put a liner package in as suggested, you still need to allow for this settlement so even then you will not have proper seals to approach NZ.

Having said that, I was at a log home yesterday that I built in 86. It was not natural logs but rather what the industry calls "D" shaped and has tongue and groves on top and bottom. The owner is still very happy with the home however the cedar shakes have run their course so we will be putting a metal roof on it this summer. It just has a forced air n.g. furnace which was sized as we would for a stick built at the time and he has no complaints with the heating.

Now if you really want to approach NZ, sell the packages, build an ICF home and cladded it with 1/2 log siding. ;-)