Passive House Institute US

What Passive House Institute US does

Passive House Institute US (Phius) is a Chicago-based 501(c) nonprofit founded to develop and administer passive building standards, professional certifications, and project certifications for the North American market. Its core technology consists of climate-specific passive building standards (Phius CORE, Phius ZERO, and prescriptive/commercial variants) coupled with proprietary modeling and design tools, including the WUFI Passive energy modeling tool, the METr Design Tool, and a curated database of over 1,000 pre-approved climate data sets. The organization's product surface spans professional credentialing (CPHC, CPHB, Rater, Verifier, Trades Professional, Associate), training delivered through an online LMS and in-person sessions, third-party project and product certification services, the Phius Alliance membership program with 12 regional chapters, and the annual PhiusCon conference. Phius has certified over 11.2 million square feet of passive building projects and reports a network of more than 3,000 Phius-trained professionals and 1,000+ Alliance members across North America.

Phius makes money primarily through transactional, fees-based revenue streams tied to its certification ecosystem. Training courses are priced between $450 and $750 depending on program and membership status, with separate exam fees (recertification exams at $150 across Verifier, Rater, and Builder tracks). Project certification, product certification (windows, prefab panels), and Phius Alliance membership dues add recurring and per-engagement revenue. Go-to-market relies on a sales-led model targeting architects, engineers, builders, consultants, and energy raters; an event-led model anchored by PhiusCon and regional chapter events; and a community-led flywheel powered by the Alliance member network. Phius holds co-requisite partnerships with the EPA (ENERGY STAR, Indoor airPLUS), the DOE (Zero Energy Ready Homes), and RESNET (HERS Rater program), making Phius certification a regulatory-grade signal within the North American high-performance building market.

The organization is led by Founder and Executive Director Katrin Klingenberg, with operational leadership from Certification Program Director James P. S. Ortega and Senior Scientist Graham S. Wright, PhD. It is governed by a Board of Directors, Industry Advisory Council, and Technical Committee. Operating as an independent nonprofit with no parent company, venture backing, or M&A activity disclosed, Phius pursues growth through product-line expansion (retrofit and commercial standards), geographic extension (regional chapters across the US and Canada, with mention of activity in Japan), and policy advocacy aimed at embedding its standards into building codes and incentive programs.

Name

Passive House Institute US

Legal name

Passive House Institute US

Website

https://phius.org

Company type

Private

Founded year

2008

Operating status

Operating

Headcount range

11–50 employees

Short description

Passive House Institute US (Phius) is a Chicago-based nonprofit that develops climate-specific passive building standards, certifies professionals and projects, and delivers training across North America, serving architects, builders, engineers, and raters seeking high-performance building credentials.

Ownership category

akta.pro rank

Headquarters

HQ city

Chicago

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Marketing or Sales, Infrastructure, Others

Revenue model

1. Professional Certification Fees: Phius certifies professionals through multiple credential programs: Phius Certified Consultant (CPHC), Phius Certified Builder (CPHB), Phius Certified Rater, and Phius Certified Verifier. Each certification requires training completion and exam fees.
2. Training Programs: Fee-based professional training courses including self-guided and instructor-led formats for all certification tracks. Training fees range from $450-$750 depending on program and membership status.
3. Project Certification: Certification fees for passive building projects (residential and commercial) submitted for Phius certification compliance.
4. Phius Alliance Membership: Annual membership dues providing access to exclusive resources, discounts on training/certifications, and member benefits. Certified professionals receive automatic membership.
5. Product Certification: Certification fees for high-performance building products including windows and prefabricated panels.

Pricing tiers

Go-to-market motion3 records

Distribution channels5 records

Marketing channels8 records

Core offering

Passive House Institute US (Phius) maintains climate-specific passive building standards and certifies passive building professionals, projects, and products across North America. The organization delivers training and certification programs for consultants, builders, raters, verifiers, and trades professionals, and operates the Phius Alliance membership network supporting adoption of high-performance building practices.

Product overview

Phius (Passive House Institute US) is a certification and training organization that maintains the Phius climate-specific passive building standard for the North American market. The organization operates as a platform of interconnected certification programs, training courses, and professional credentials. The core offerings include professional certifications (Phius Certified Consultant CPHC®, Phius Certified Builder CPHB, Phius Certified Rater, Phius Certified Verifier) paired with corresponding training programs, along with specialized software training (WUFI Passive, THERM, Window Simulator). Phius also provides building project certification services, product certification for windows and panels, and maintains the Phius CORE and Phius ZERO standards. The Phius Alliance membership program provides ongoing access to climate data, resources, and regional chapter networks. The organization has certified over 11.2 million square feet of passive building projects and trained over 3,000 professionals.

Differentiator

Problem solved

Functional benefit

Products and services

• Phius Certified Consultant (CPHC®) Training Training program that prepares professionals to design and consult on passive building projects, covering building science, passive building principles, energy modeling with WUFI Passive, and Phius certification requirements. Designed for architects, engineers, and consultants pursuing the Phius CPHC credential.
• Phius Certified Builder (CPHB) Training Training program for builders focusing on construction techniques, quality assurance, and implementation of passive building standards for single-family and multifamily projects. Designed for construction professionals pursuing the Phius CPHB credential.
• Phius Certified Rater Training Training for RESNET HERS Raters and similar professionals to conduct field testing, inspections, and verification for Phius certification compliance on residential projects. Designed for raters pursuing the Phius Certified Rater credential.
• Phius Certified Verifier Training Advanced training for verifying multifamily and commercial passive building projects, covering field testing protocols, commissioning, and third-party certification requirements. Designed for verifiers pursuing the Phius Certified Verifier credential.
• Phius Trades Training Training program for construction trades professionals (Enclosure Specialists) focusing on passive building construction techniques and quality workmanship. Designed for trade contractors pursuing the Phius Certified Trades Professional credential.
• WUFI Passive Training Training on WUFI Passive energy modeling software for designing passive buildings, including single-family and advanced multifamily modules. Designed for consultants and designers using WUFI Passive in Phius certification work.
• Introduction to THERM Workshop Workshop teaching thermal bridge analysis using THERM software, covering 2D heat transfer modeling and moisture risk assessment for building components. Designed for designers and consultants needing thermal bridge analysis capability.
• Phius Window Simulator Training Training on the Phius Window Simulator tool for evaluating window performance in passive building applications. Designed for designers specifying windows for Phius-certified projects.
• Passive Building Foundations Training Entry-level introduction to passive building principles and Phius standards, delivered as a self-paced online course awarding 12 CEUs. Completion results in the Phius Associate designation.
• Phius CORE Prescriptive Path Workshop Workshop on the prescriptive approach to Phius CORE certification for single-family projects, eliminating the need for whole-building energy modeling. Designed for designers of single-family detached residences, townhomes, and duplexes.
• Project Certification Services Third-party certification of passive building projects ensuring compliance with Phius standards, including design review, verification, and quality assurance. Offered to project owners (developers, homeowners, schools, commercial owners) and delivered through certified consultants and verifiers.
• Product Certification Services Certification of building products (windows, doors, and prefabricated panels) for performance in passive building applications. Provided to building product manufacturers seeking eligibility in Phius-certified buildings.
• Phius Alliance Membership Professional membership program providing access to over 1,000 climate data sets, networking, exclusive resources, discounts on training and certifications, and local chapter access. Available to industry professionals pursuing Phius credentials and engagement in the passive building community.

Quantifiable outcome

• 11.2 million+ square feet of passive building certified
• +1 more outcomes

Named customers3 records

Segments6 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Seven partnerships are on record, tiered core and minor.

• Phius AlliancecoreChannel Partner/ Reseller/ DistributorPhius Alliance is the membership arm of Phius consisting of more than 1,000 industry professionals from across North America. Regional chapters provide local networking, education, and advocacy for passive building adoption.
• EPA ENERGY STARcoreStrategic or Co-development PartnerPhius integrates with EPA ENERGY STAR certification programs as a co-requisite for project certification. Raters must maintain ENERGY STAR partnerships.
• DOE Zero Energy Ready HomescoreStrategic or Co-development PartnerPhius projects require compliance with DOE Zero Energy Ready Homes program specifications as co-requisite certification requirement.
• RESNETcoreStrategic or Co-development PartnerPhius training and certification integrates with RESNET HERS Rater program, with raters required to be certified through RESNET QA providers in most states.
• EPA Indoor airPLUScoreStrategic or Co-development PartnerIndoor airPLUS certification is a co-requisite program for Phius project certification, ensuring indoor air quality standards.
• Energize ConnecticutminorGTM or Marketing PartnerThrough BuildGreenCT's Connecticut Passive House community, Energize Connecticut offers 75% cost reimbursement for Phius professional training under their Passive House & All Electric Homes Initiative.
• City of DenverminorGTM or Marketing PartnerThe City of Denver may reimburse professionals for the cost of Phius training through their Climate Action, Sustainability and Resiliency department's Professional Development Rebates program.

Scale indicators5 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Passivhaus Institut (PHI): The Darmstadt, Germany-based originator of the international Passive House standard. Phius is effectively the North American adaptation of PHI's framework and competes/coexists with PHI's own international Certifier/Passive House Designer ecosystem. They share underlying building science DNA but Phius is climate-tailored to NA conditions.
• U.S. Green Building Council (USGBC): Operates the LEED green building rating system, the dominant North American voluntary green certification framework for buildings. LEED and Phius both certify professionals and buildings, and increasingly overlap on net-zero / decarbonization pathways, putting them in direct competition for designer and project-level adoption.
• International Passive House Association (iPHA): The global network of Passive House stakeholders, with member organizations across dozens of countries. As the worldwide umbrella for Passive House professionals, iPHA both competes and coordinates with Phius for the same practitioner and project pipelines outside PHI's home German ecosystem.
• Green Building Initiative (GBI): Runs the Green Globes certification program alongside other ANSI-accredited green building assessments. GBI is a direct alternative to Phius for owners/developers seeking a third-party-certified high-performance building rating in North America.

Emerging players

• Architecture 2030: A nonprofit advocacy and standards organization driving the 2030 Challenge for net-zero carbon buildings. Targets the same designer/owner decision-makers as Phius and shapes the demand pool that Phius certification ultimately serves.
• Building Performance Institute (BPI): A credentialing body for building performance and home energy professionals (Building Analysts, Envelope Specialists). BPI competes with Phius for technician-level training dollars and influences the rater/verifier talent pool Phius draws from.
• Enterprise Green Communities: Provides green building certification and technical assistance specifically for affordable housing — directly intersecting with Phius's multifamily certification opportunity, and competing for developer-driven project certifications.
• International Living Building Institute: Operates the Living Building Challenge and Petal certification programs — rigorous performance-based green building standards often cited alongside Phius in the high-performance / zero-carbon conversation. Targets a similar self-selected audience of leading-edge design professionals.

Broad incumbents

• RESNET: The Residential Energy Services Network operates the HERS Index and trains/rates the certified raters that Phius relies on for residential verification. While a partner (rater co-requisite), RESNET is also the incumbent energy-rating brand that Phius certification sits on top of.
• ASHRAE: The dominant HVAC and building systems standards body, including 90.1 and thermal comfort standards that Phius-style certifications integrate with. Competes for technical authority on thermal envelope, IAQ, and energy performance at the code/specification level.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights7 records

Customer concentration

• Xx.com/PHIUS1
• YouTubeyoutube.com/channel/UC37iRgzDQK-OgyoLTOn7GoA
• Facebookfacebook.com/PHIUS1
• LinkedInlinkedin.com/company/passive-house-institute-us-phius-/mycompany/verification/?viewAsMember=true
• Instagraminstagram.com/phius_official

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Passive House Institute US