Blackout-Readyby Crisis-Ready Society

Home / The guide / House design

House design · Choose the structure and foundations · design-11

Choose a construction system

The wall and roof system sets cost, speed, insulation level, thermal mass, DIY potential and how easy permits will be. Choose it against your climate, skills and local approvals.

How

  1. Timber frame: low embodied energy, easy to insulate and extend, little mass; well suited to hot humid climates; needs termite protection (Your Home).
  2. SIPs: foam core of typically 4 to 8 inches between structural skins, fast, airtight and well insulated (DOE); needs controlled fresh-air ventilation; medium to high cost.
  3. Rammed earth: high mass, very durable; insulation hard to add; suits large day to night swings; cold climates need external insulation (Your Home). New Zealand covers it under NZS 4298.
  4. Adobe or mud brick (and compressed earth block, a pressed version): lowest embodied energy if soil is local, low cost if owner-built; needs added insulation in cool climates (Your Home). HUD recommends adobe walls of at least 16 inches in hot arid areas. In one US university study, blocks of clayey sand with 6% cement pressed at about 10 MPa averaged 3.4 MPa compressive strength, with wide scatter, so local soil and mix must be tested.
  5. Earthquake warning for adobe, rammed earth and compressed earth block: unreinforced adobe is prone to collapse even in low-intensity earthquakes. Adobe collapse caused more than 40,000 deaths in the 1970 Peru earthquake.
  6. In any seismic zone above the lowest category, use earth walls only to an engineered design or a recognised earth standard, with ring (bond) beams and reinforcement. Otherwise use a framed or reinforced structure with earth as non-structural infill or mass.
  7. New Zealand example: NZS 4297 covers engineering design of earth buildings, NZS 4298 materials, and NZS 4299 earth houses not needing specific design. See design-26 for seismic design.
  8. Straw bale: excellent insulation (HUD cites about R-33.5 for 3-string bales laid flat), needs dry bales, breathable render and big overhangs (Your Home).
  9. Cob: covered by IRC Appendix U (US) where adopted; fire and cold-climate thermal data still limited (ICC).
  10. Shipping container: steel is a strong thermal bridge and condensation risk; ICC published guideline G5-2019 for reviewing containers as buildings.
  11. Masonry and concrete: high mass, durable and fire resistant; needs external or cavity insulation; suits cold and temperate climates; can be a liability where only cooling is needed (Your Home, NZ).
  12. Score your top three options against climate fit, cost, local builder skills, permit route and your own labour.

Safety: Unreinforced adobe, rammed earth and compressed earth block walls can collapse in earthquakes. In seismic zones use an engineered design or a recognised earth standard.

Do these first

Sources

  1. Construction systems. Your Home, Australian Government, accessed 2026-11
  2. Structural Insulated Panels. US Department of Energy, Building Science Education, accessed 2026-11
  3. Construction systems (Smarter Homes guides). Building Performance, New Zealand Government (MBIE), accessed 2026-11
  4. Southwest Housing Traditions, Chapter 3: Adobe, Rammed Earth and Straw Bale Wall Systems. US Department of Housing and Urban Development (HUD User), accessed 2026-11
  5. Straw bale. Your Home, Australian Government, accessed 2026-11
  6. Cob Code Appendix Approved for the 2021 IRC. International Code Council, Building Safety Journal, accessed 2026-11
  7. The International Code Council Releases 2019 Guideline for the Safe Use of Repurposed Shipping Containers. International Code Council, accessed 2026-11
  8. Homogeneity and Isotropy of Compressed and Stabilized Earth Block Material (Journal of Materials in Civil Engineering 36(10), 2024). University of California, Davis and University of South Carolina (eScholarship), accessed 2026-11
  9. A review of local construction practices applied on unreinforced adobe buildings in South America (Cocco, Brando and Spacone, Frontiers in Built Environment 8, 2022). Frontiers in Built Environment, accessed 2026-11
  10. NZS 4299:2020 Earth buildings not requiring specific design. Building Performance CodeHub, New Zealand Government (MBIE), accessed 2026-11

Open in the interactive guide