Climate risk is priced on location — not on performance. Two buildings on the same street, one designed to survive an extended grid outage and one that fails in days, are underwritten identically. Fortiia certifies the difference.
The operating model
Fortiia is building the credit score for buildings.
A permanent performance record for every certified building - used by insurers, lenders, and buyers the way FICO is used in consumer finance. Define the score. Run the platform. License the output.
What we are building
01
A Certification Framework
The Fortiia Resilience Standard defines four tiers and five performance pillars for new construction - the first simulation-based building resilience credential in the US market. Builders earn a permanent, documented certificate backed by physics modeling.
02
A Certification Engine
The Fortiia platform ingests actual building data and determines what each building has earned - escalating to full hygrothermal and dynamic thermal simulation for higher-tier certifications, powered by the C3RRO engine. Every path is closed by a PHIUS-credentialed rater, on site.
03
A Performance Data Layer
Every certified building enters a permanent, queryable record. As the registry grows, it becomes the actuarial dataset that gives insurers building-level risk visibility - the data infrastructure that has never existed until now.
The standard
Each tier documents verified performance. Issued only on completed evidence, with third-party inspection.
RDY
Fortiia Ready
Thermal survivability and envelope baseline verified. Entry-level credential for climate-conscious builders.
RSL
Fortiia Resilient
Full 5-pillar certification. The market standard credential - the one insurers, lenders, and buyers will reference.
FTF
Fortiia Fortified
All pillars plus extreme climate scenarios and site fortification. Premium tier for high-exposure markets.
ZRO
Fortiia Zero
Optional zero-carbon add-on layered onto any tier. Positions certified buildings for ESG and green finance instruments.
Every Fortiia certification is evaluated across five performance pillars - each mapping to a specific, measurable physical outcome.
The market
$70T
The built environment - the only asset class of this scale with no standardized performance score.
Global real estate market estimate · UNEP / World Bank
$100B+
Annual insured losses from US climate events - losses the market cannot currently price at building level.
Swiss Re sigma · annual average 2020–2024
55–76%
Claim-frequency reduction for certified homes - actuarial proof that simulation-based performance predicts real outcomes.
IBHS · 40,195 homes · Hurricane Sally 2020 · peer-reviewed 2025
Why now: PHIUS REVIVE 2024 was published in July 2024. As of mid-2026, no funded competitor has built a commercial platform on it. The first-mover position is open.
Founded by the scientists who built the tools
Fortiia's scientific foundation was not assembled for a startup pitch. It was decades in the making - built by the researchers who created the standards the industry already uses.
Florian Antretter
Chief Executive Officer
Co-developed WUFI at Fraunhofer IBP - the hygrothermal simulation tool used by building scientists across 175+ countries. Founded C3RRO, the cloud-deployed simulation engine powering the Fortiia platform. Built US market fluency through applied research at Oak Ridge National Laboratory (ORNL) and the National Renewable Energy Laboratory (NREL).
Fraunhofer IBP · WUFI · C3RRO · ORNL · NRELKatrin Klingenberg
Chief Science Officer
Co-founded the Passive House Institute US (PHIUS) and spent two decades building the professional infrastructure for high-performance building in North America — including co-authoring PHIUS REVIVE 2024, the peer-reviewed standard on which Fortiia is built.
PHIUS · PHIUS REVIVE 2024Mission
"To make building resilience measurable, certifiable, and insurable - so that every building built in a climate-exposed market performs when it matters most."
— Fortiia Building Intelligence
Get in touch
Fortiia is currently in early engagement with select builders, insurers, and investors.
All inquiries are treated with strict confidentiality.