We used rigid fiberglass (duct board) to insulate our foundation.  Extruded polystyrene is not allowed for this application in the southeast due to termites.  Since the cement slab will serve as the majority of our thermal mass it's crucial that we insulate it from the outside air.

Post pillars for our portico

We made certain to air seal with caulk in even the hard to get to seams like where the wall sheathing laps over the top of the stem wall.

Here we are adding the ledger boards for our back screen porch rafters.

The chimney block is going up for the wood stove flue.

The portico takes shape.

Cement fiber siding going up (no, the house will not be yellow .  Durability and longevity are key qualities of any efficient home.

Here's the south face of the home after the majority of trim and siding has been applied.  Note that the rigid fiberglass on the foundation wall is covered with vinyl flashing.  This will keep it dry (crucial to maintain r-value), keep insects out (crucial for longevity), and keep the wind off the insulation so it can perform.

North side of the home.  Note the limited windows.  This is done intentionally when drawing the floor plan.  By locating closets, bathrooms, etc. on the north wall we're greatly increasing the home's performance.  No matter the window, windows always have a significantly lower r-value than the wall.  North facing windows provide no solar gain and only lose heat from the living space.