Heading toward 60. I'd like to downsize to a house with 500 to 1000 sq feet. I'd prefer the 500 but wife wants at least the K.
I'd like something simple but with about 6" of insulation in the walls, 12" in ceiling, 3 pane windows. An alternate source of power to reduce utility costs. Thinking about a poured basement with the 500 sq ft house, but wife likes the two story idea better (don't see much of a difference).
What would it cost to build something like this? Any ideas on how to keep it toasty in the winter but have very low utility bills?
Any experience with the Amish builders in the central Ky area?
6" of insulation can have different effectiveness depending on the type of insulation used. Become conversant in R-values of insulation types. Find out how much you would like to achieve and then calculate the necessary thickness to achieve your desired R-values (and overall U-values) and compare pros and cons of the different types, including cost.
You would have to check a lot of boxes before the payback on alternative source of power makes much sense for a 1,000sf house. If you are budget conscious at all, and have normal utility access you shouldn't waste your time with alternative energy considerations. I have a feeling that Tesla's home battery product (and the like) will make your 2016 solution feel like an 8-track-esque blip in technology in the coming years - especially if you plan on staying in this home until you die.
Your biggest asset in reducing energy costs will insulating and sealing the building envelope.
Secondarily, focus on orientation to the natural environment (specific site). The orientation to the sun (and any immovable shade creating objects) is the priority. Orientation to prevailing winds is the second major factor in this. The long axis of the building should run east-west to maximize the south facade and its windows.
You should aim for window surface area of roughly 5% of the total sf of the house. The vast majority of these will be on the South facade to allow low Winter sun to penetrate deep into the interior space. Extend roof overhangs to block the higher summer sun from entering the space and added unwanted additional heat.
Determine how late in the winter/spring you would want additional heat from the sun to heat your house. Then enter in you site location and the date on NOAA's sun tracking calculator to determine the altitude angle of the sun at 12 noon on that day. In a sectional drawing, use this angle to draw a line beginning at the lowest edge of your typical southern window extending up and away from your building to the sun. Then, extend the top face of your roof pitch line until it intersects your original "12 noon cut-off day sung angle line." This intersection will give you the optimal depth of your roof overhang to allow winter sun to enter your house until the day you want it to stop.
For an aging couple, you should build a one story house - no basement or second floor. The difference between a basement and second story is the fact you can get natural light, ventilation, and egress (in the event of fire/emergency) from windows on a second story. A basement is a dark deathtrap by comparison.
I would look into local historical home design of your geographic area from before the advent of central heating and air. Those structures were designed to passively take advantage of their climate as much as possible.
You should set off to design a house in this manner as if you were ignorant of modern technology for the most part (except for spatial/plan requirements). Then go back and augment it with modern technology (better insulation, etc.)
In the end, you should buy a trailer. It will lose just as much value as your Eco-tiny home (since there won't be a market when the fad passes), but you will have a lot less headaches in the process and get a home that was put together in a controlled factory environment rather than a one-off that was built in the elements.
