Glenn Ellen Fire Restoration Breaking Ground / by Michael Cobb


We are happy to announce our first fire restoration project breaking ground in Glenn Ellen.

A common challenge associated with burn properties is the mandated hazardous material cleanup. This cleanup effort often leaves a large shallow hole where the house foundation previously existed.

Figuring out ways to turn this depression into a design asset - and not a metaphor for anyone’s state of recovery - has been an ongoing interest of Hedgpeth Architects. In the many months following the fire, it has been important as we design homes, to find ways to turn the unexpected effects of the fire into design assets. An early lesson is shown here, as we break ground on the foundation.

Working with MKM Structural Engineers and Chapman Construction, we have implemented a waffle mat technology for the foundation of this residence. The client wanted a residence that flowed out easily into the landscape and related well to a surviving swimming pool and future surrounding gardens.


Using upside-down form boxes made from recycled milk carton containers, the foundation forming process creates a series of voids and thin concrete fins under an otherwise conventionally thick concrete slab. Normally the grading associated with a waffle mat slab is more extensive than a conventional slab-on-grade or a stem wall foundation and this can be a prohibitive expense for homeowners.

Nevertheless, the waffle mats superior performance in association with the expansive soils prevalent here in Sonoma County make it a tempting candidate regardless of this grading challenge.

In the wake of the fire another expense has unexpectedly reared its head. People are struggling to bring the floor levels of their new homes up to where they were before the fire. As homeowners contemplate the expense of trucking in and compacting fill, the waffle slab becomes a “lifting up” proposition instead of an “digging down” one.

Slab Comparison 2.jpg

A big thank you to MKM for introducing us to the technology and Chapman Construction for expediting the install as the rains approach.