A 50-year structural warranty is possible when two conditions are met: a structural system engineered to known and certified performance standards, and a corrosion protection system with documented long-term performance. VAST buildings satisfy both conditions through the FormSteel structural platform and AlloyCoat™ proprietary metallic coating.
Most commercial buildings in New Zealand carry no meaningful structural warranty beyond the standard 10-year weathertight guarantee under the Building Act. The reason is straightforward: conventional construction uses a combination of trades, materials, and subcontractors whose interfaces create points of uncertainty. The structural engineer certifies their design. The builder certifies their workmanship. The coating supplier certifies their product. No single party can stand behind the performance of the complete assembly for 50 years.
VAST eliminates this problem by controlling the entire structural system from raw material to final building. Every section is manufactured by FormSteel Holdings. Every connection is designed by SIQ structural software to the specific loads of that building. Every surface is coated with AlloyCoat™, a proprietary metallic alloy coating developed specifically for New Zealand and Australian environments.
Conventional galvanising fails at cut edges and connection points — precisely where steel is most vulnerable. AlloyCoat™ activates at compromised surfaces rather than failing there. The alloy chemistry mobilises to protect cut edges, drilled holes, and scratched surfaces through a self-repair mechanism that conventional zinc coatings cannot replicate.
Every VAST building is specified to the correct corrosivity classification under AS/NZS ISO 9223 — from C1 for dry inland locations to C5 for marine environments within 500 metres of salt water. SIQ selects the AlloyCoat™ specification automatically from the building's coordinates.
The VAST 50-year structural warranty covers the structural integrity of the building's primary steel frame. It is a legally binding commitment from FormSteel Holdings, not a manufacturer's product warranty. If the structure fails to perform to specification within 50 years under normal use conditions, FormSteel Holdings is liable.
This is a material difference from the standard practice in which warranty responsibility is fragmented across the design team, contractor, and material suppliers.
The 50-year structural warranty is included as standard on every VAST building. It requires no additional premium and no special application.