Building a nontoxic house that is safe for a chemically sensitive person is not the same thing as building a home from sustainable, green materials. My house is made of concrete, metal, and glass, because those are materials to which I don’t react, but concrete comes at a high environmental cost.
I did not want to feel like I was living in a commercial building, so on the interior of my house I used natural materials as much as possible. The masonry heater and sauna are made of untreated soapstone, and unsealed wood is used in the sauna. Most of the walls are covered with raw clay plaster, and I opted for rounded edges on the windows and corners. Overall, the interior feels earthy, cozy, and comforting.
The walls were plastered by James Henderson’s crew from NW Natural Homes, LLC. (https://www.nwnaturalhomes.com) Last month James returned to check the walls. They were plastered four years ago, with a formulation he created and used in his own home before it was applied in mine. It is now available commercially as Gold Hill Clay Plaster Zenith. (https://www.goldhillclayplaster.com)
The walls are doing well. Minor cracks appeared at the top of two walls, due to the expansion and contraction of the house as it settled. They were easily repaired.
Some brown spots appeared shortly after the plaster was applied and they worried me, but it turns out they occur when minerals cluster near the surface of the plaster. They can be repaired with water, as can accidental dents and dings. Here is a video showing the dissolution of a brown patch and the repair of some dents.