We are building a 2500 sq ft house in Oregon.  Winter temps rarely go below 30, we pretty much have a constant 40 something winter temp (with lots of rain).  We have an abundance of wood on the land, and we don't want to require the grid or fossil fuels to heat our home.  We are using a concrete slab on grade - radiant floor heat is an option, but I've heard that emissions can be a problem with wood boilers.  Our house is long - there is a "wing" for bedrooms - this design works best for the site, but heat delivery to the outer rooms may be a problem if we use a wood stove or masonry stove.  Any suggestions??

http://www.centralboiler.com/?src=overture

I've been looking at these myself. 85% efficient and you can use them to heat your house and water. If you are off grid and have a great wood resource, in MY OPINION, this is the way to go. If it were me I'd focus on making my home very energy efficient and build with icf's or sips or at least use tons of spray foam insulation to need less heat to begin with.