MCNZH, Second Floor. As built on the left, and "flexing" on the right.

Durability is absolutely key to sustainability. Everything we buy, every precious drop of fossil fuel that we burn, should be put to best use by creating as much value from it for as long as possible.

I see no reason why the Mill Creek NetZero Home (MCNZH) can't stand for hundreds of years. To be as useful as possible during its long lifetime, we designed it to flex with the changing needs of its occupants.

So Peter Amerongen and I got together and designed the future renovation. It will convert the second floor of the home into a self-contained suite (the side door downstairs will get isolated from the main floor suite by framing in a new wall).

The plan on the left of the above picture is the second floor as it will be built, and the one to the right is the second floor as a self-contained suite. Up is south. The stairs from the main floor are on the left, represented by a block of green, and the "ship's ladder" to the loft is shown as well (beside the stovepipe for the wood burner).

After we first build, myself, my wife, and my two kids will live in the home (hence the two bedrooms + a master bedroom). Once we decide to convert the second floor to a suite (zoning permitting, of course), we will remove the wall between the library and master bedroom and the wall between the master bedroom and the bathroom. To make this easier, we haven't framed those walls yet. We won't do so until we pour the concrete floors, so that once we do rip them up, the concrete floors under them will be intact.

MCNZH - second floor, view from the northwest corner of the master bedroom. Once the concrete floors are poured, a wall will be erected between the windows to separate the library from the master bedroom.

We will also put as few electrical wires in those walls as possible (code requires at least one plug, on the wall between the library and the master bedroom). Plus, the electrician will add electrical in the bathroom for a future stove, and for above-counter plug ins. Lastly, the plumber will rough in a spot for a washing machine in the hallway closet.

We hope to maximize the utility of the MCNZH by making it a flex house. The enduring usefulness of this home makes it a greener asset - one that fully utilizes the resources that went into building it.

(cross posted at raisingspaces.com)