Hi all! Ever sat around a dreamed of more efficient ways to run, repair, heat or cool you home? What if you were starting from scratch? That is what I would like to do in the not too distant future! I have researched many alternative building methods from Cobb (adobe) to Straw Bale (neither are good for the southern climate). or maybe you know something I havent thought of or considered. I would LOVE to hear suggestions from the forum on some really "Outside the box" not mainstream wood or steel stud, OSB and drywall with asphault shigles . . . . ideas for truly Green Building. I (we) would love to go back to a basic structure of living where the living expense does not box us into the rat race (no more keeping up with the Jones's). Ideally, we would like to sell our 2k sq/ft monster energy consumer with all the amenities (hot tub, pool, blah blah blah) and begin construction a little bit in the country on a Pay as you go construction (tired of bank interest). is it a Pipe Dream?? All things being equal and current building codes considered - My ideal critera would be: a. Lowest cost per sq.ft using as much renewable or even rare earth and environmentally friendly products as practicably possible. Structurally and well insulated walls (hot humid summers and cold dry winters in NC) b. keeping cost in mind, heating and cooling options that are basic, yet effective. (thermal mass, wood gasification, etc.) Geothermal is the very exciting, but not necessarily cost efficient for this budget. c. natural filtering to handle greywater usage and aerated septic (to code) to provide the most efficient aerobic environment for nature to handle the un-pleasantries. d. gasification furnace with water heating and direct heat exchange via plenum? Radiant heating in floors? e. single story vs. the more cost effective 2 story method (cheaper to go up than out)? I am not against using many convention forms of construction especially if I can combine them with real ingenuity to save or gain in other areas. I would love to hear any and all relative suggestions on any one of the above or even some new off the wall but realistic suggestions. Mainstream and retail materials, I could probably build conventional for 60-75 a sq.ft with a lot of the work done myself, but Ideally I would like to be below that, and produce a nice (not cobbled together) home to live in for the next 20 or 30 years. Some ideas may sound crazy to those who work in the industry mainstream (as I currently do), but for many years, people survived with the most basic style of living and suffered not in the least. Quite frankly, many likely profited from a more basic quiet living when they weren't stressed by the daily hustle and bustle and so driven to be a CONSUMER of all things. We have had that, and it turns out to be "Not so much" for us. We wont be without basics such as power, water, TV and internet, just a more serene way of living and less rat race. Not primitive, just basic, and most importantly "PAID FOR"! I welcome any and ALL suggestions and or techniques you may have thought of, or thought provoking "what if's" you may suggest. I ask the nay sayers and critics to hold their critiques and not staunch the free flow of idea exchange. PLEASE! Lets see what an open and positive forum for discussion can produce. Of course, words of caution from experts are also welcomed so that dangerous things are not attempted. Thanks in advance for your careful considerations and ideas! JH in NC, USA

if you ask me it is not a pipe dream. either that or I'm dreaming too. now...regarding the building suggestion ....green building suggestions...I'd say that double stud frame 12" wide at least, made from 2x4 24" oc filled with cellulose are hard to beat from all points of view....especially for a diy. If you build it from factory made panels it can also be quite fast and will limit the amount of possible mistakes as well. a shape as close as possible to a cube (2 stories) with proper orientation and proper window placement will help a lot. this I think would be the best "within the box" option that you have.

http://chandlerdesignbuild.blogspot.com/2009/12/increasing-attention-is-being-drawn-to.html

for "outside the box" options - 18" rammed earth walls (6"rammed earth - 6" insulation - 6"rammed earth) reinforced with rebar are the cheapest (materials costs) option but you'll have to put a lot of work. the results are nothing short of spectacular. put a rocket stove(google it - it's super cool and cheap) inside and you're set.

http://becgreen.ca/wp-content/uploads/2010/10/Rammed-Earth-House-Sylvia-Cook-009.jpg

good luck
Adi
http://torontonetzerohouse.blogspot.com/

Adi - THANKS!  Good stuff. . . . Rammed earth is really cool ! I had't seen that before.  I am all over the websites you gave, thanks.

The rocket stove . . . OH YES!  Love it.  I have already built a cheapo mock up of a rocket stove/Rocket Mass heater with a few of my own modifications:  side air inlet to pull air from the outside (negative pressure of the consumed oxygen pulls drafts into the house - counter productive) with a damper to control how hot it burns and how much fuel it consumes.  A taller throat opening for the burn chamber, with a cap,  to load it for longer burns, or load it with with bark/mulch scraps that will continuously feed, a necessity for sure for overnight on the coldest winters (its 33 ouside now and heading towards 26 overnight).  Its still a work in progress, but I like the results so far.

I have entertained an adobe or brick type floor with a reflective barier underlining and radiant heat/cooling under the brick, again, heating/cooling a mass for a slower release, and long loops burried 6' or more for summer cooling if needed. . . havent worked out those details yet.

These are Excellent suggestions, more more more.   Thanks again.

JH

The key to building inexpensive housing is to build it small, simple, durable.

Build it slab on grade with a frost protected shallow foundation, fully thermally isolated from the ground
Something like 5-8” eps under the slab
Build everything on 2 foot centers
Go for a Single story ranch design, rectangle with the long side due south 24X32 is about right for size
Use 2X4 and do a 12” wide double wall, use zip sheathing on the outside wall carefully tape the seams.
Use cellulose for walls
Ceiling is a done with trusses, scissor truss 10” energy heal go for R60 in the ceiling use cellulose here also. 2 ft overhangs all around
Airtight drywall approach on the walls and ceilings.
Windows mostly on south side all casement high solar gain low e triples on south. Low solar gain triples on other 3 sides.
Kitchen and bathroom/laundry back up to each other with a common wet wall.


For HVAC, keep it very simple. A minisplit heat pump for heating and cooling. A backup electric baseboard radiator for very cold weather. A small HRV for fresh air. A couple of ceiling fans.
For dhw use an integrated solar hot water system that has an electric coil in the tank for backup.
Low cost, durable DIY buildable.

I gringe whenever someone talks of building with wood, bet those people hit by the tornado rebuild using wood frame
safedomes.com
Spray closed cell foam is the way to go

Humm,
every day I drive past WOOD  houses built in the 1700's, yet the  concrete bridges built in town from the 1930's are all having to be replaced.   Do I then conclude that wood lasts 4 times longer then concrete?  For the majority of the US population tornado's are a non issue.  

IF you are arguing that concrete +foam is a viable building conbination, then I agree.  I bet most people would not want to DIY one of your domes though.

Cheers,
Eric

Ooooh.  I dont know about the closed cell foam.  I was excited about it for a rehab job on a home that badly needed re-insulating. 

While researching icynene for this project, I came across 2 different posts (Different Mfg) where foam was retaining water (mold) and the other about adhesion issues and pulling away from the substrate.  Once you cover it up, you'll never know.  Everything is subject to gravity, settleing, and the like, but the water retention issue really took me by surprise.

I think I shall wait on any spray foam use that I cant see, and check on a couple times a year.  I like the idea and the product, but its more expensive than typical insulation types, and relatively unknown.

I like the double wall system.  24x32 is doable, but for a family of 4 (fo 5 more years) , we would need a second floor, or larger footprint. 

Slab on grade is preferable, but I would like to have radiant heating under the slab.  I have considered q 100 gal thermal storage (water) tank in a seperate but attached building for combined hot water, heating, and radint floor heat. with an outdoor wood fired gasification boiler.  I have sketched up plans to capture the maximum heat exchange for many purposes, possibly including a small steam driven turbine if I chose to be off grid.

Personally, I am Not so much on heat pumps, below 35-40 degrees they are not effective.  Nothing worse than  pushing cold air out ofyour registers in the winter. 

But I REALLY like the idea of a Rocket mass setup, and my focus is on that for the time being.  Its simple, yet very effective.  I am incorporating a small thermostat controlled servo to damper at the air inlet to control burn rate and call for heat.  if the thermal mass (cobb , stone, or crete) cools to below a required point, it will allow more air into the rocket stove and thus increase output from the thermal a=mass. .

Definately like a trussed roof if I use conventional roof methods. 

LED Lighting for sure, I am working toward zero grid dependance if possible and practical.  Flourescent where I need better lighting.

Thanks Eric for your input!

Nice!  Thanks David.  Domes arent really my thing.  I once had the opportunity to buy a dome shaped house in TN (wood framed) and it just weirded me out. :)

Guess that makes me a square!  LOL.  Just kidding, but I do like the concept of the indestructible homes.  this should be required sheltering at the coast and in the midwest!!!!

Underground shelter at the coast are a NO NO!

A monolithic concrete structure can be built to look like a typical square home including pitch concrete roof only difference is that there is no wood and no roof to blow off and no air leaks all rebar and concrete Future construction is here today

do not dismiss heatpumps so fast. look a bit into mitshubishi mr slim. very well priced and very effective even at very low temperature. here is one example of a net zero that uses them:

http://www.solartoday-digital.org/solartoday/20081112/#pg26

I agree with what eric said about frost protected shallow foundation. I also think it is the best solution for such a project. regarding the radiant setup - it is just a waste of money in a super insulated house. you can put a loop in the slab just for fun and to have something to play in combination with solar heated water but don't think that you 'll ever feel warm floors. if you'll raise the temperature of the slab to feel warm to the touch your house will over heat because it can't loose all that heat fast enough. now....if you also have a stove .....you'll have to pick what you want to use.

this is the beauty with the superinsulated houses - you don't need to overcomplicate the heating or cooling system.

Adi

Now thats a great article. Interesting thought about dissapating heat from a warm floor. I suppose I had envisioned just that. warm feet and a comfortable room. . not very practical to have both. Still highly intrigued by the thermal rocket mass heater. . . . . , that in combination with the frost protected shallow foundation . . . I'll have to wear slippers I guess! LOL. thermal mass release and low pawer consumption ceiling fans to keep the air temeratures even should work nicely. Presently, in our conventional framed home on a crawl, the majorith of our heat hovers at the 10' ceilings unless we run the ceinling fans to even out those temps.

you will not have to wear slippers. the slab should around the same like room temperature even when it is not hit by the sun. that is if you use the FPSF (frost protected shallow foundation) so I don't think you'll have any comfort problems.

the usual problems from regular houses (cold floors) do not translate in the same way into superinsulated houses.

regarding the low power consuption fans - I doubt you'll need them and here is why: If you build a tight house you'll need some type of ventilation. you have many options but in my view a HRV or ERV are your best choises. if you use a HRV with recirculation capabilities you can set it so let's say 30 minutes will ventilate and 30 minutes will recirculate/mix so .....no need for fans. if you look at venmar eko line you'll see how efficient those things are (24 watts at 49 cfm, 2.04 CFM/watt). the calculation are a bit more complex than that - you'll have to measure what kind of heating/ventilation needs and you'll have and size the equipment accordingly but a super eficient envelope simplifies everything else.

go to builditsolar.com and read everything - start with the proper envelope, shape and orientation - add the right amount of glass/overhangs and thermal mass in the right places - calculate what you still need in terms of heating cooling - decide the simplest, cheapest most proven and maintenance free systems that will satisfy your needs.

there is no need for highthech superexpensive stuff

keep an eye on my blog if you want a step by step example (I'll start the actual construction in the spring)

Adi
http://torontonetzerohouse.blogspot.com/

Adi ! Wow, what a fantastic Blog! Please do keep it up to date, and of course chronicle the build. Great house plan too. A little Ultr modern looking for my tastes, but I like the concept.

I read the ENTIRE blog page, and you are a fantastic writer. You drew me right in and I had the sensation of being in the old store/house. I look forward to more posts!!!

JH in NC

Simple things few seem to consider.

Ironically, you mention outside the of box, when what you want is a box, a cube to be exact.

A home is typically a box.

The geometry of boxes can save you heating and cooling costs by reducing your heating balance point.

Here's the deal. As boxes go, a cube has the least exterior surface area/volume for any box shape.

Heat loss for a well sealed box will be dependent on exterior surface area. Given an outside tempertature, and inside temperature, and an insulation level, the heat loss, ignoring windows and doors, will be the same for each square metre of exterior wall. The more square metres of exterior wall, the more heat being lost.

If we assume 8 foot ceiling height as a minimum and therefore the optimum ceiling height to miniminze exterior surface per square foot of floor space, we can assume an 8 cubic foot column of volume above any square foot of floor space, and 1 foot for joists, we can divide the volume by 9 to get the floor area, in order to calculate the exterior surface area divided by the floor area.

Or, we can consider that a box has six sides, and for optimum configuration three floors, so 27 feet high, and so 27 feet on a side. You could construct a larger square footage building based on 36 feet on a side, and four floors, that would have the same characteristics.

A three story cubic building 27 feet on a side for the inside of the heated space, will provide the least heat loss per floor area of any boxlike building, of the near the same square footage. 9 feet is the optimum height for a floor, so three foors make 27 feet. Such a building would have 4374 square feet of exterior surface. Of that 729 square feet are basement floor, and 729 square feet is exterior ceiling. The floor area would be 2187 square feet.

This gives a very good ratio of 2 to 1 exterior surface area compared to floor area. You lose some floor space to stair wells vs. a bungalow. I challenge you all to calculate the exterior surface area of your homes vs. floor area and compare. Include basements floors and exterior ceilings, not just walls.

The four floor 36 ft on a side version, would have 3888 sq ft, and the same 2 to 1 ratio of exterior wall to floor space.

So a full basement with a full two stories above, or a full basement with 3 stories above, in a cube will be optimal for minimizing heat loss by using geometry.

If you change any dimension, or add any extra living space that sticks out from the basic cube shape, you will increase the exterior surface area per floor area ratio, and increase heat loss, raising your heating balance point.

So if you truly want to be optimal you start with one of these two shapes, and you make changes judiciously as a compromise of needs, wants, and asthetics vs. energy efficiency.

Now a garage is not typically heated. Ours is insulated with R12 and has double glazed argon windows, but is not heated. The garage is located on the side of the house that presents to the prevailing north westerly winds. We find that the garage stays above the outside temperature without heating, just heat loss from the attached house and solar gain. The back of the garage has a 5 ft x 5 ft picture window facing southwest. The garage shelters the heated house from the wind and is except in the coldest weather quite comfortable, without heating, to fetch things from the car. 

The garage acts to reduce heat loss, in two ways. Because it is warmer than outside temperature, the rate of heat loss on that side of the house is reduced. Also, because the garage is between the rest of the house and the preveailing winds, there is less heat loss due to buffeting winds.

We have no sliding doors. All doors are on hinges and seal tight.

If you live in a cold climate and heating predominates, the basment floor is ground temperature and typically uninsulated. If I had it to do over, I would put a layer of styrofoam down before pouring the basement floor.

I was thinking about mini air to air heat pump that extracts heat from outgoing hrv air and dumping back inot house to have no net loss through hrv. expensive yes but some sort of refrigeration unit should be an available add on to hrv

hrv-heat pump combinations are already available from some european manufacturers. one of them who sells such things in North America is Nilan.

adi
http://torontonetzerohouse.blogspot.com/

A wood gasifying boiler would be overkill, and I would doubt if in floor radiant would be appropriate, your heat load would be too low.