[Greenbuilding] passive solar homes - floors

[Kat]

Hi all,

I've got a client of my very own (my first!) and I'm trying to convince 
them to go with the simplest passive solar system - that of direct 
gain.  I've got a few questions:

1) I'm reading _The Passive Solar Energy Book_, by Edward Mazria, 
copyright 1979.  Is this generally a good source?  Is there another 
source I should follow up with, to fill in holes, or find correct 
information?

2) Does anyone on the list live in a well-functioning direct-gain 
passive solar home that uses the floor as part of the system?  If so, do 
you happen to live in a temperate climate like Portland, Oregon?  And if 
so, what do the floors feel like in the winter?  Are they warm, tepid, 
or cool on the feet?

3) Any suggestions for how to convince the client that they will like a 
thermal-storage floor, when they are a die-hard fan of wood floors, and 
think that concrete is going to be too hard?  Or is this going to be an 
impossible task because concrete *is* too hard?  Is it nasty to live 
on?  These floors would be joisted - the concrete (or dirt, or whatever 
I could convince them to use as thermal storage) would go on top of the 
joists.

Thanks!

-Kathleen