REBUILDING RIGHT
The Truth About Non-Combustible Construction
NEW TO THE TERMINOLOGY?
START WITH FIREPROOF HOMES EXPLAINED →
After a fire, homeowners are often given conflicting information about building materials, costs, timelines, and what terms such as fire-resistant, concrete, and non-combustible actually mean.
This page looks beyond the labels. It explains what homeowners should verify, which questions they should ask, and what evidence a builder should be able to provide.
PHNX shares this information to help families make informed decisions, whether or not they ultimately build with us.
MYTHS, CLAIMS & EVIDENCE
Common Claims. Clear Evidence.
Some statements about non-combustible construction sound reassuring but leave out important details. Here is what homeowners should understand and what they should verify.
MYTH 01
Non-combustible single-family construction isn’t feasible.
FACT
Type I non-combustible construction has long been used for larger buildings. PHNX adapts these principles to single-family homes through a wood-free structural system and the patent-pending PHNX Longspan™ roof and floor assembly.
MYTH 02
Any concrete home is non-combustible.
FACT
Concrete walls alone do not make the complete structure non-combustible. Wood may still be used in the floors, interior framing, sheathing, or roof. The entire structural assembly must be evaluated.
MYTH 03
Non-combustible homes always cost more and take longer to build.
FACT
PHNX uses its Longspan™ System to make Type IA non-combustible homes cost-comparable to conventional wood construction, with an anticipated 8–12 month build schedule. Net-zero energy performance can save $2,000–$4,000 per year in utility costs, and PHNX Homes qualify for significantly lower insurance premiums through Mercury—adding up to substantial long-term savings.
MYTH 04
Home hardening is the same as non-combustible construction.
FACT
Home hardening improves a conventional home by protecting vulnerable areas such as vents, roofing, windows, and exterior finishes. It can reduce wildfire risk, but combustible wood may remain throughout the primary structure. Type IA non-combustible construction goes further by changing what the walls, floors, framing, and roof are made from.
DOCUMENTED EVIDENCE
The System Behind the Claim
Removing wood from the structural system requires more than concrete walls. The PHNX Longspan™ roof and floor assembly addresses one of the most persistent barriers to Type IA non-combustible single-family construction.
PHNX Longspan™ Roof Assembly
USPTO Patent Pending Publication #US-2025-0277366-A1
Wood-free roof and floor framing
No plywood roof sheathing
Designed as part of a Type IA structural system
A BROADER RESPONSIBILITY
Building Better Standards
The work does not stop with the homes we build.
PHNX shares what we learn from designing, permitting, and constructing Type IA non-combustible single-family homes. We want homeowners, builders, design professionals, insurers, and code officials to have clearer information about how materials and complete structural assemblies perform.
We also participate in the broader conversations that influence building standards and code. Our position is simple: better decisions begin with clear definitions, documented evidence, and questions that any builder should be willing to answer.
We will continue to share what we know and help families find reliable information, whether or not they ultimately build with PHNX.
A PRACTICAL RESOURCE
Questions to Ask Any Builder
Homeowners are often given very different answers about building materials, fire resistance, costs, timelines, and insurance. Clear information should not depend on which builder you choose.
Use our Builder Comparison Tool to ask consistent questions, document each builder’s answers, and understand what evidence they should be able to provide. PHNX created this resource to help families make informed decisions, whether or not they ultimately build with us.
