Simpson Gumpertz & Heger

Simpson Gumpertz & Heger is an engineering firm founded in 1956 and headquartered in Waltham, Massachusetts. It occupies an unusual position in the market, doing new structural design and building enclosure work alongside one of the country’s most established forensic and failure investigation practices. That combination is the point: the firm’s design guidance is informed by decades of taking apart buildings that leaked, cracked or fell down. Enclosure consulting covers curtain wall, roofing, waterproofing and thermal performance, and SGH is regularly retained by owners as a peer reviewer on complex facades. The firm handled building enclosure and structural engineering on the $306 million critical care tower at Bon Secours St. Mary’s Hospital in Richmond, Virginia. It also works on infrastructure, nuclear and industrial structures, and maintains a materials science laboratory.

Three MIT professors started the practice in 1956 — Howard Simpson, Werner Gumpertz and Frank Heger — and incorporated it two years later. That academic origin still shows in how the firm is organised. Alongside structures and building enclosures, SGH keeps standing groups for advanced analysis, performance and code consulting, and applied science and research, the last of which underwrites work that most consultants would subcontract.

Headcount now sits at roughly 800. Headquarters is split across two Boston-area addresses: about 110,000 square feet at 20 CityPoint in Waltham, which holds the physical, materials and digital laboratories plus an expanded experimentation centre, and a smaller downtown office of about 14,000 square feet in the Prudential Tower.

The office map has grown steadily rather than by merger. Boston opened in 1956, San Francisco in 1975, Washington, D.C. in 2000, Los Angeles in 2003, New York in 2005, Newport Beach in 2008, Oakland in 2012, Chicago in 2014, Houston in 2015, Atlanta in 2020, Denver in 2023 and Tampa in 2025. Staff passed 500 in 2015 and 750 in 2024.

Work is grouped into ten markets — commercial, culture and entertainment, education, energy, government, health care and life sciences, industrial, infrastructure and transportation, residential, and science and defense. Enclosure services split into three practical buckets: assessments and due diligence surveys that document existing conditions and support dispute resolution; selecting, detailing and integrating wall and fenestration systems, including custom curtain wall, panelised assemblies and structural glass; and roofing and waterproofing design, third-party installation inspection and performance investigation.

The project record is unusually legible. The firm analysed the 1981 Hyatt Regency walkway collapse, carried out the global analysis of the World Trade Center towers under impact damage and fire for the National Institute of Standards and Technology, and worked on the John Hancock Tower, Grand Central Terminal, Epcot’s Spaceship Earth, NASA’s Vehicle Assembly Building, the MWRA Deer Island egg-shaped digesters, Yale’s Beinecke Library, the New York State Capitol, Seabrook Station, Diablo Canyon and, in 2023, the settlement remediation at Millennium Tower, 301 Mission Street in San Francisco.

Owners typically bring SGH in for one of three reasons: a new structure or facade that needs designing, an existing building behaving in a way nobody can explain, or a peer review where the answer has to survive scrutiny. The forensic practice and the design practice sit in the same firm, which is the point.