[dredmorbius]

I really don't see the method as appropriate for dense urban construction. It seems far better suited to rural spaces with little access to modern building materials. Though this really isn't my bailiwick.

There's a design for dense modern urban areas: it's brick-and-timber multi-story construction. You'll find it evident throughout Europe, with basic designs largely established by the 19th century if not before. The advantage of such construction is that it greatly minimizes land use, and hence transportation, a major concern for urban lifestyles. Designs which require large areas, aren't amenable to dense and multistory construction, and whose construction itselft is disruptive to adjacent properties (digging for earth fill in this case) strike me as a poor fit.

In rural areas it might work, though again issues of moisture and cool climates would concern me.

There's also an existing high-density earth-based construction model, the pueblo:

http://upload.wikimedia.org/wikipedia/commons/9/95/USA_09669...