make your walls 1.5 feet thick and use hay bales !!!
i think the r-value of hay is well over 150
if they are lightly treated or sealed they present less fire hazard than wood...
its also very inexpensive...usually free...especially when compared to any insulation rated over r-50
i'm not sure what is used to seal or spray them with...if at all...
not hay, never hay, hay is the leaf of alfelfa, with some grass, you want to use straw, the stalk of wheat, oats, rice, barrly, it's like the differnce between the trunk of a tree, and the leaf of a tree, straw, if kept dry will last many many years, there are straw houses that are 100 years old, even if you let it get damp, in the garden, when used as mulch, it will last a year or two, simaler to wood chips used as mulch.
If you want to build a house out of straw, the temputre will be very stable, I've worked on 8 differnt straw buildings in the last 4 years, and helped teach a number of weekend classes on building with this methed as well, I would highly recomend taking a class befor trying to build your own house out of straw because there are some details that can get tricky, and having hands on expearnce is invaulable, even more so when there isn't anyone round that is familuar with what you are doing that you can ask questions of, however when someone trys to tell you that building a house out of straw will be cheaper to build they are not telling the whole truth, it's like tell you that walking is the cheapes way to get around, it will take alot of time to walk 15 miles each way to work, but it will be cheap, right? so how much time do you have, building with straw can be cheap, but it will invalve alot more work then building with wood, if you pay someone else to build it for you it will cost the same as building with wood, the mateerials will cost a little less, but there is more man hours invalved in building with straw, the house will cost less to heat and less to cool.
here are a few houses that I've either worked on, or that friends have built. http://www.nbtsc.org/~ryland/straw/
also my friend travels the world and builds houses out of old rubber tires, crushed soda cans & cement...
they built a house down the street from mine (back in vermont) and i got to see the house in many stages...
it uses solar panels and maintains a year round avg temp (in cold *** vermont) of 58° with no additional energy...it takes very little energy to make that house comfortable...
they have some kind of commune of these structures out in arizona
i guess thats their home base...
just throwing another out there...worth investigating...
oh and if you dont love this picture you dont belong on this website
lol...bold statement i know...
As for cooling, you might want to look into a swap cooling system. We use it here in Utah and I think it's wonderful. It won't cool as much as an A/C system, but it's plenty more efficient.
I think this is called a "swamp cooler". When I lived in Layton, Utah it worked great in Utah's dry climate. It's humidifying the air to cool it.
If the area of Texas your in is anything like southern Louisiana, you don't need any extra humidity. Maybe a high effiency A/C unit, with as high of a SEER rating as you can find.
On another note, think about how your house site is oriented, for southern exposures. Maybe try to block the hot sun, minimize windows on that side, use landscaping as a shield/sunblock.
engery stare homes are like getting a fuel efficent car, anything over 28mpg is thought of by most people as "good" energy stare homes are "good" basicly the best rating for an energy star home will only tell you that the house is not 100% bad, most energy star ratings don't take in to acount solar gain, mass, good design like roof overhangs, they are simply a mesure of quality of appliances, and thickness of insulation, if you design a house that does not need to be heated or cooled with a fuel or other sold energy, is can not be energy star rated, just like bicycles don't have a MPG rating, they are above that.
I would try and design the house so that the tankless water heater is located near where the hot water would be used. Our house has a 50 foot line inbetween the bathrooms and the hot water heater, and not only does it take forever to get hot water, but wastes a ton of energy. Starting from scratch you should be able to prevent this.
Also, you may want to look for a site that provides shade from the hot afternoon sun (in the west). Planting trees, or some sort of windbreak on this side is also a possibility, and would probably moderate prevailing winds.
I recently visited one of my teacher's homes that he built himself. There are many lessons in efficiency that I took from his home...it's amazing! His house is a total of over 3,000 square feet. Here's the things he showed me:
*Basement is the full footprint of the house. It is also totally underground except for a space about 12 feet wide at the back of the house where a set of double doors allow access. The basement stays a cool 67 degrees year round - and yes, I was there this week and the Georgia summer heat was in full force and it was pleasantly cool down there.
*The entire house (interior and exterior walls) is built with 2x6's instead of 2x4's. This allows for greater insulation.
*No insulation between house floor and basement ceiling. This allows for the cool air to more easily transmit through the floors in the summer and the warm air to transmit through the floors in the winter.
*Low-E glass throughout.
*Brick exterior. The sun rises on one side of his house (which is heavily shaded by trees) and sets on the other. The setting side of his house gets most of the sun during the day and there are NO windows on this side of the house. The front of his house has a 12 foot wide porch on it, so none of the front windows get hit with heavy sun. He also has a tin roof. I don't know if it hels with efficiency, but it's going to last a helluva lot longer than a shingled roof.
All in all I am very impressed. He said he compared energy bills with his neighbor (who's home is less than half his size) and his bill was less than half his neighbor's. He did a lot of the work himself and was his own general contractor, which allowed him to get a smashing deal on the house. I hope to take some of these points to heart when I finally decide to build a home of my own.
Check around for financing. Some lenders will lend considerably more money on an energy efficient home because they know the resale value will be higher and your energy bill will be less allowing you to make the higher monthly payment.
Kevin A Thornton
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