The girls discovered snow today and decided not to venture far from the coop.

Our story in brief:
I was sitting in the backyard one morning last spring, sipping coffee and gazing at the few green shoots of grass then visible when my son's abandoned wooden swing set caught my eye. I looked at the 4x4x8 ft wooden play tower and thought to myself. "Now there's a perfect frame for a chicken coop". I never drew up any detailed plans, just stripped down the play tower and reused the wood along with some scrap wood from some old basement shelves and a bit of new wood from the lumber yard to put together a two story coop big enough for four chickens. The side yard was added after a couple of months using a portable dog yard we got off the local freecycle list. We got the roof shingles off freecycle too.
There's a 40 watt shop light hanging in one front corner for those short winter days as well as a 100 watt ceramic heater in the light socket you can see through the window (double-paned plexiglass) to take the chill off those really cold new England winter nights (thermostat is set for 20 degrees F). I insulated it with 3/4 in foam board covered with luan on the inside. The coop is boarded up tight for winter but the sides and back are hinged and can be opened up in warmer weather. You can see one corner of the nest box in the back. It runs the length of the back side.
Here's how it looked in the beginning when the chicks were still keeping warm in a box in the basement.

There must be millions of these wooden swing sets just waiting to be converted into coops!