- Beyond Sustainability - The Case for Regenerative Design
- Understanding Place - Climate, Site, and Solar Geometry
- The Six Integrated Systems - An Overview
- Building with the Earth—Natural Materials
- Passive Solar Design - Heating and Cooling Without Machines
- Off-Grid Energy Systems - Power from the Sun
- Water - Catching, Storing, and Cycling
- Liquid Waste Treatment - Botanical Systems
- Food Systems—Buildings That Feed
- Community Design - Scaling Up
- The Integrated Design Process
- Appendix A: Glossary of Key Terms
- Appendix B: The Pangea Textbook Series
- Appendix C: Key Design Principles at a Glance
- The Regenerative Community Vision
- Site Assessment and Land Reading
- Land Use Law and Legal Frameworks
- Master Planning for Regenerative Communities
- Infrastructure Systems Integration
- Housing Typologies and Density Design
- Community Governance Structures
- Economic Models for Community Development
- Phased Development Strategy
- Community Resilience and Long-Term Stewardship
- Appendix A: Legal Entity Comparison Chart
- Appendix B: Community Design Checklist
- Appendix C: Glossary of Community Development Terms
Every natural building material requires a protective surface finish. Natural plasters — applied as exterior and interior coatings over tire walls, adobe, cob, or straw bale — protect the underlying structure from moisture, provide a finished interior surface, and contribute to the building’s moisture management and vapor control characteristics.
Earth plasters, made from clay, sand, and fiber, are the most basic and most available of natural plasters. They are applied in two or three coats, sanded smooth when dry, and can be finished with a lime or silica top coat for durability and water resistance. Earth plasters are entirely non-toxic, can be made from site-sourced soil, and have excellent breathability. They are typically used for interior applications; for exterior use in climates with significant rainfall, a more durable lime or silica finish coat is recommended.
Lime plasters, made from hydraulic or non-hydraulic lime and sand, are harder and more moisture-resistant than earth plasters. Lime has been used for building finishes for thousands of years; traditional lime plasters on historic adobe and stone buildings have survived centuries of weathering. Lime plasters are breathable — they allow moisture vapor to pass through — which makes them compatible with earth-based wall systems that need to dry toward the exterior. They are also self-healing: small cracks re-seal over time as moisture dissolves and redistributes the lime binder.
Review Questions
1. What is embodied energy and why is it relevant to material selection in regenerative design? Give two examples of conventional materials with high embodied energy and two examples of natural materials with low embodied energy.
2. Describe the process of building a tire wall from the point of obtaining tires through pounding and stacking. What makes tire walls particularly effective as thermal mass elements?
3. Compare adobe and cob as building materials. What do they have in common? How do they differ in terms of construction method, appropriate climate, and design possibilities?
4. What are the structural characteristics of straw bale construction? What is the most important design consideration for ensuring straw bale walls perform well over time?
5. What is hempcrete, and why is it described as a carbon-sequestering material? In what climates is hempcrete most appropriate?
