Sunken Down

Prompt

What is the best way to build a basement or earth-bermed shelter?

Findings

A living space below grade is a technical and financial endeavor that should only be undertaken with great care. The earthworks required can completely transform a site. Before backfilling, we use layers of waterproofing, exterior rigid insulation, and drain board to ensure that the below-grade walls never have to be dug up for future servicing. The lateral pressure of the earth backfill can also greatly affect engineering, especially in high seismic areas. Traditionally, this method relies on concrete or masonry foundation walls. However, we see these materials as problematic both for their resource intensity and for their lack of resilience over time. We think—with the right detailing—alternatives like permanent wood foundations are superior. This type of foundation can eliminate the logistical and material challenges of concrete from a project entirely.