Expertise
- - Services
    Engineering
    
    Bridge Engineering
    
    Construction Engineering
    
    Fire Protection and Life Safety
    
    Geotechnical and Geological
    
    Heavy Movable Structures
    
    Materials Engineering
    
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    Seismic Engineering
    
    Structural Engineering
    
    Architecture
    
    Architectural Finishes and Materials
    
    Building Enclosures
    
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    Enclosure Commissioning
    
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    Research
    
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    Field
    
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    Condition Evaluation
    
    Construction Observation and Troubleshooting
    
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    Litigation Consulting
    
    Design
    
    Design-Build
    
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    Systems and Components
  - Markets
    Clients from markets and industries across the built world rely on our interdisciplinary team of engineers, architects, and materials scientists to develop an all-around understanding of their needs, provide expert consultation on available options, and develop solutions that deliver lasting value.
    Buildings
    
    Construction
    
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    Industrial
    
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    Testing and Research
  - Laboratories
    Our extensive in-house laboratory and testing capabilities are second to none. With laboratories in our Austin and Cleveland offices as well as a 70,000-square-foot state-of-the-art testing and applied research facility at our Northbrook, Illinois, headquarters, we have the advanced testing and forensic capabilities to solve virtually any problem related to structures, construction materials, or manufactured components.
  - People
    We strive to make a positive difference in the world by consistently setting the standard in every key aspect of our business, starting with the extraordinary people we employ. Connect directly with an expert on our team.
Projects
- - SEARCH FOR
    WJE PROJECTS
    Our team has investigated, tested, and innovated on more than 200,000 projects involving almost every type of construction material, structural system, and manufactured component. We take a hands-on, empirical, and investigative approach to every assignment. Although materials, technologies, and structures change, our basic philosophy doesn’t. Founder Jack Janney’s advice to “ask the structure” continues to guide our project work today.
Knowledge
- - Articles
    We’re passionate about our work and believe it is our responsibility to share our experiences and lessons learned for the enrichment of our clients and the advancement of our industry. We hope you learn something new that helps you better understand and address a challenge you face in your own work.
  - Webinars
    We regularly host webinars on interesting topics and challenges related to the built world. We encourage you to search through our library for subjects of interest to you. Watch, listen, and share with others.
  - Videos
    Experience our capabilities, project work, laboratories, and company culture as told by our staff and clients in this selection of videos.
  - Websites
    Learn the “what” and “why” and “when” of facade and seismic ordinances in various cities throughout the United States, as well as our recent efforts with sustainable (low carbon) concrete.
    
    SustainableConcrete.com
    
    FacadeOrdinance.com
    
    SeismicOrdinances.com
Careers
- - Careers at WJE
    A career at WJE means working alongside industry gurus to solve the most significant, interesting, and challenging problems of the built world. Whether you'd bring years of experience to our team or you're just out of school, a career at WJE may be the right choice for you.
  - Job Openings
  - Benefits
  - FAQ
  - Mission, Vision,
    and Values
    Using a set of key principles to guide us, we aspire to consistently deliver practical, innovative, and technically sound solutions—to make a positive difference in the world by consistently setting the standard in every key aspect of our operations, starting with the people we employ, the expectations we have, and the environment we create.
Offices
- - OFFICES
    With hundreds of professionals in North America and Europe, WJE can respond quickly to assignments around the world. No matter where you are, we can help.
    AMERICAS
    
    Atlanta
    
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    San Francisco
    
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    Washington, DC
    
    EUROPE
    
    London
About
- - Mission, Vision,
    and Values
    Using a set of key principles to guide us, we aspire to consistently deliver practical, innovative, and technically sound solutions—to make a positive difference in the world by consistently setting the standard in every key aspect of our operations, starting with the people we employ, the expectations we have, and the environment we create.
  - Our History
    Each year, our employees contribute their time, resources, and energy to a wide variety of organizations and events, seeking to make a difference. Our people work hard to leave their communities better than they found them.
  - Safety
    Commitment
    The most important thing in our business is the safety of our people. We strive for a safe, accident-free work environment through a dedicated and concerted effort by each and every individual.
  - Sustainable
    Solutions
    WJE is committed to sustainability in construction, applying a long-term lens to materials selection, performance testing, systems integration, repair design, and conservation.

KNOWLEDGE // ARTICLES

The Imperfect Storm (Window)

David S. Patterson, Senior Principal, Princeton
Jeffrey N. Sutterlin, Associate Principal and Unit Manager, Princeton

In high-performance buildings, windows are often the first place condensation appears. Understanding why requires a closer look at how glazing systems interact with interior humidity, airflow, and thermal resistance.

In this article, architectural engineer Jeffrey Sutterlin, and architect David Patterson address the importance of proper air sealing of interior glazing systems and the potential problems that can result without it.

This article appeared in the April 2026 issue of Construction Specifier and is posted with their permission.

READ ARTICLE (PDF)

Founded in 1956, Wiss, Janney, Elstner Associates (WJE) is an interdisciplinary firm of engineers, architects, and materials scientists committed to helping clients solve, repair, and avoid problems in the built world. Supported by unparalleled laboratory and field-testing capabilities, our experts draw on more than seventy years of experience to deliver innovative and practical solutions grounded in deep technical expertise.

Ask the Structure and Solutions for the Built World are trademarks of Wiss, Janney, Elstner Associates, Inc.

© COPYRIGHT WISS, JANNEY, ELSTNER ASSOCIATES, INC., NORTHBROOK, ILLINOIS. ALL RIGHTS RESERVED.

Engineering

Architecture

Laboratory

Field

Forensics

Design

SustainableConcrete.com

FacadeOrdinance.com

SeismicOrdinances.com

AMERICAS

EUROPE

KNOWLEDGE // ARTICLES

The Imperfect Storm (Window)

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