Just a couple issues...

"the Germans have a house design that only burns 800 watts a day, and has no external heating source."

Watts is a unit of power.  Watt-hours, kilowatt-hours or something thusly is a unit of energy... "800 watts a day" means nothing, unless you mean watt-days which would be a weird unit.  The [Rocky Mountain Institute www.rmi.org/] is also superinsulated and uses passive solar heating and uses no fossil heat.  I think they even have a greenhouse that they grow bananas in...and they're located in a place that gets really cold.

"It relies on passive solar and the heat and light generated by its inhabitants."

I've never seen glowing people before :)

From wikathingapedia:

"The watt is named after James Watt for his contributions to the development of the steam engine"

burning 800 of him a day could be considered another holocaust.!

I presume they mean the house runs at an average of 800W which seems reasonable. That would be 19.2 KWh per day or about £1.80 per day where I come from.

I highly doubt that's what it means.  Running a house at 19.2 kWh a day is nothing to write home about.  I doubt they'd be making a big deal of a home design of that nature.  19.2 kWh is a fair amount of energy, and not especially good.  
The Americans have a 800 watt-hours per day house as well:

http://www.treehugger.com/files/2006/07/300whr_a_day_th_2.php?a=0

I think it actually looks quite cool. seeing things like this restores my faith in humanity!
Thank you for the link, which may have been where my '800' number came into my head.
good point-- I was being sloppy.  My number must be wrong.

http://www.passivhaustagung.de/Kran/Passivhaus_Kranichstein.htm

couldn't find the actual power usage for the house on the site, and my German isn't good enough to translate all of that graph.

http://www.passivhaustagung.de/Kran/Passivhaus_Kranichstein_15Jahre.pdf

there as an interesting piece in the New Yorker a couple of years ago, pointing out that RMI is an environmental disaster compared to a couple in a 1 bedroom flat in Manhattan, in terms of energy consumption.  The difference being the cars and the amount of living space.

"there was an interesting piece in the New Yorker a couple of years ago, pointing out that RMI is an environmental disaster compared to a couple in a 1 bedroom flat in Manhattan, in terms of energy consumption.  The difference being the cars and the amount of living space."

Do you have a link?  It would seem a little unfair to compare a commercial business building with something like 40 employees to a residence of 2 people.  I doubt, even with the extra space, that a Manhattan flat could even come close to matching the RMI in terms of fossil energy used...the RMI doesn't even have a heating system, it relies on passive solar and the heat generated by the occupants and computers/lights/etc inside.  Now the cars thing...that you could get them on.

I think it was on a per person basis.

The key was the driving (or lack thereof).

Unfortunately the New Yorker archive is not online in any form that I can find.

Dear Valuethinker An english version of the passivhaus information is available here. http://www.passiv.de/index_10PHI.html - click the british
flag top right.
The energy use in the Passive haus Kranichstein (Passivhaus)
the diagram to the right at http://www.passivhaustagung.de/Kran/Passivhaus_Kranichstein.htm gives annual (final)energy consumption per m2.

Heating      10.5 kwh
Hot water     7.2 kwh
Electricity  14.7 kwh
total 32.4 kwh/m2/year

This translates into approx. 60-65 kwh/m2/year in Primary energy ( energy at the source).
At the moment some 6000 passivhouses have been built in Germany as single family homes, row houses, schools, highschools, sport halls etc. So the Passivhaus concept is going mainstream. The passivhaus it not rocket science, but application of traditional materials in an optimal combination, coupled with good workmanship.  The important things are an airtight vapour barrier inside, trible glazed windows with insulated frames, ditto doors, 1-1½ feet insulation - floor-walls-roof and a ventilation with >85% heat recovery. The houses are tested with blower door for airtightness. Costs are +5-15% of ordinary buildings. The passive house principles can be applied to old buildings as well. Solar, PV etc can be added, off course and reduce energy consumption further.
regards/ And1

thank you!