Flipping Green Houses

I've been reading thru the stuff put out by the International Energy Agency in cooperation with the G8 meetings. Interestingly, they project that the same amount of carbon might be saved (by 2050) via efficiency improvements in the home, as by changes in transportation.
And that's assuming hydrogen is up to 10% of transport energy by 2030--far from assured. It also assumes electric hybrids are adopted far more than today.
The point is, efficiency in the home is just as important to carbon savings as efficiency at the pump. The methods are cheaper and more DIY, and are amortized in a home which will stand for >20 years (the average life of a car in the US is 7 years). Here's how the improvements break down:
The IEA projects a large amount of savings through insulation and heat pumps. They claim that 37% of energy used in a home is for heating, and that proper insulation and the use of heat pumps can reduce this by 75%. Their projected cost for such improvements over 20 years is 1-2 cents per kWh saved.
The heat pump comes with a $500 or 10% federal tax incentive and $200 from energySTAR incentives in Oregon. The same incentive project gives roughly $0.30/sq foot back for improved insulation. These lower the capital cost to $3500-550=$2950 for the heat pump and $2000-1500 =$500 for the insulation. Orgeon's credit for insulation is absolutely insane: they pay around 80% of the materials cost. Everybody should be doing it.
At a $20 mortgage value increase per dollar energy saved these improvements are worth (in principle) around $9000.
19% of the energy used in a home is for lighting. Here they suggest the obvious, which is higher-efficiency bulbs.
For both of the above the IEA also discusses the possibility of central computer control of lighting, heating, security, and safety (i.e. fire detectors et al.). The only method of controlling heat today is the thermostat, but as I flip through catalogues I reckon I could put one together for the low thousands---essentially a PDA programmed to talk to USB-enabled power outlets (also here) and web-enabled thermostat connected to room temperature detectors and enabled air vents.
The PDA (probably running the open Symbian OS) would give you independant control of each room's temperature, together with lighting. In the process of a retrofit one could easily make a home 'enabled' by running USB and hi-def video output thru the walls to a central computer (e.g. a media center with a very large hard drive for DVD storage). Any room of the house could hook up to the television/movies/internet just by plugging a keyboard and tv into the wall. The central computer would also track smoke alarms that never run out of batteries (and perhaps a security system?)
The web-enabled thermostat runs you $200 and hdmi/usb enabled wall plates run around $50 each. Cable installation would presumably take place during the larger retrofit and might run in the low hundreds. A new computer (no monitor) would run around $1500. I feel like this would be a large value-adding geegaw that might be worth $6000 to the prospective buyer. Could pop in speakers to the rooms as well.
8% of future improvements in home efficiency will come from newer appliances (i.e. other than air conditioners). In most cases, though, the cost savings in a new appliance does not excuse replacing the old one. There are small incentives in Oregon for new dishwasers, fridges, or washing machines of around $80-$200.
Finally there is solar water heating, which is very much DIY. Active solar air heating is still about 3-5 times more expensive than traditional heat/air and won't be commercial for decades. A DIY flat-plate water heater runs around $700 before $200 in incentives and pays back immediately.
So here's the picture:
Year one, I live as cheaply as possible, in Oregon, working both as a teacher and as a renewable energy salesman.Year two, I buy a home with a mid-term mortgage. I dump around $8k into home improvements, including (but not limited to) efficiency improvements.Year three, I sell the home and move on with pocketed money and experience.
The home improvements start with better insulation and windows, together with a new heat pump. Together these run $5500, $2500 of which is paid back to me. The improvements should add $8000 in value to the house.
They continue with a solar water heater, which will cost $700, $150 of which will be paid back. It adds $1000 to the value of the house.
Next in line is computer control, of my own design. This aspect may have its own commercial application. The cost is $2500 and I estimate its worth is at least $5000.
Finally I install efficient lighting and appliances. Also, stuff which may be of value: a deck, or flooring, or a new kitchen. An 'arizona' room adds sq ft to a house which generally exceeds the required investment. These soak up the remainder of my $10k investment.
I then hope to sell the house for (at least) $20k more than I bought it for.