The sections show the relation of the interior platforms to the exterior walls, the ramps, and the progression of spaces along the arc, with various ceiling heights. On the interior the rectalinear element dominates the curved element, but the complexity of the curved element ceiling in contrast to the plain ceiling of the rectalinear element helps balance the two, as the curve can be read through the rectangle.

Here are details of a wall extension containing south facing windows which reflect the light down through the wall and into the space, mostly to spread diffused light onto the ceiling. This is preferable to skylights, as it is winter focused, and does not need covering in summer. The sides are canted to reduce the space used by the channel to a minimum, so to reduce the areas of non-insulation in the wall, although this is critical only below the roof line.

The solar domestic hot water heater will be located above the plumbing core and the pumps will run off the PVs. The cold water entering the system will be preheated in the rock bed, to reduce the size of the collector for reasons of visibility relative to the design covenants.

The entrance at grade on the north which becomes a descending ramp is sheathed in Anazasi stone with small culvert windows aligned to the ramp. Ducting for the hot air system will run under the slab from the greenhouse and south facing collectors to the rock bed for storage. Fans will run off the PVs.

This model is still somewhat raw, with some fenestration not yet designed. The cross- axis intersection is more subtle, with dominance changing depending on one's vantage point, which creates an asymetrical equality. At one point one of the ramps protrudes slightly at the intersection to reveal itself. A photovoltaic array serves as a canopy betwen the greenhouse and the toolshed.

The plan of the Arc is relatively simple: split level platforms connected by ramps and sneak stairs. The west level contains the guest bedroom, toilet, shower, spa, utilities, storage, and thermal rock bed. the two levels above that are work spaces connecting to an outdoor deck and bridge. To the east is a sitting areas with a loft canopy above. The sitting area leads to the greenhouse, garden and tool shed. The model shows all the interior walls.The only enclosures are for the toilet and bedroom, which makes air distribution very easy.

Backup space heating is by a high-efficiency wood stove, the heated air being fan distributed to the lower level. This distribution system is separate from the solar/rock bed distribution, and solar and back-up should always be isolated so as not to cross-contaminate. For example: if the wood stove air heats the rock bed in the night, the rock bed's capacity to store solar energy the next day is compromised, as the capacity depends on temperature differential.