So what does this new dwelling look like? Well, of course, it could take endless form; but to provide a prototypical starting point, I created a series of designs using American housing typologies. By starting with the familiar, we can appreciate both the timeless and the contemporary--you can easily see what's new because the typical expression is well-known. These prototypes were designed to be broadly applicable, with suburban Chicago in mind--for lots slightly bigger than the Chicago 25x125. The starting point for passive design is orientation to the sun, so there are several types here: a Bungalow which can have east or west street frontage, a Cape Cod with south frontage, and a Georgian with north. In all cases, there is emphasis on indoor-outdoor flow (porches and raised bed gardens are consistent features), interesting spatial experience inside, and great natural lighting. Here's the bungalow type--traditional front porch with contemporary detailing and a green roof; traditional 2 bedrooms plus bath downstairs (back bedroom could be a family room or study open to the kitchen/dining), contemporary living and dining flow; traditional under-the-eaves second floor with contemporary master bedroom, laundry, and fourth bedroom or study. The roof lifts up to the south to let sunlight in, and the stairs and kitchen capitalize on the spatial opportunity: there would be a strong connection to the sky, but shading to keep sun out in the summer. The roof is durable metal, the siding stained cedar--warm and inviting. The walls are thick--comforting and super-efficient. Although it's just over 1,800s.f., the rooms are generous and the space and flow would be great. As with all these examples, it is designed to Passive House efficiency, which means it's comfortable and affordable to run, a truly sustainable prototype. And here's the Passive Cape Cod, sporting similar materials to the Bungalow. This type of house was common in 50's tracts, and it was during a visit to my cousin's house in St. Louis that made me see why: it's a simple, compact form that allows a lot of variation within an efficient shell...but the 50's ones are pretty stiff and self-contained. As a south-facing font door house, this one captures the sun in a dynamic entry space, and light is borrowed from that space into the central rooms (upstairs bath and downstairs hall). Like the bungalow, it has two bedrooms down and up--though again, bedrooms could be family/den/study rooms as well, so there is flexibility of use. And at about 1,500s.f., it's incredibly efficient and affordable. Finally, here is a house based on a Georgian 3-bay organization grid, but loosened up with corner windows and porches. The front door and porch are low-key to the north, while the living spaces and bedrooms open up to the south, and a screened porch to the west. Like the other two, it has laundry up by the bedrooms, metal roof, borrowed light to the interior; unlike the other two, this has a cement-board panel with cedar siding exterior palette and a full height second story with a vented attic (above R-90 to 100 insulation!). It's just under 1,800s.f., and again, would have a great feeling of spaciousness and indoor-outdoor flow. So that's a start on the road to the attainable, healthy, efficient house. I hope to build a lot of these.