About Us

MEP Engineering Services for a More Sustainable Planet

Comprehensive Services, Challenging Projects

Your Full-Service Engineering Partner

Founded in 1973, Grumman|Butkus Associates is a nationally recognized firm specializing in sustainable design engineering and energy efficiency consulting. Our award-winning services include facility assessment and analysis, MEP engineering design, commissioning, retro-commissioning, monitoring-based commissioning, and energy efficiency and LEED consulting.

We help clients achieve goals and solve tough problems, with particular expertise in energy-intensive and complex facilities, including:




Mission Critical

Senior Living

Sports / Recreation


Lab / Science

Multifamily Residential


Cultural / Religious

Pharmaceutical / Industrial

Multidiscipline Sustainable Engineering

We haven’t met a problem we couldn’t solve.

Long view of Hyatt Regency Maui at dusk with palm trees

Hyatt Regency Maui Resort and Spa

Heat recovery technology made a dramatic difference for this massive leisure property, saving energy and money

UIUC, Materials Research Laboratory exterior

University of Illinois at Urbana-Champaign, MRL and MNTL

Two complex engineering buildings received large-scale renovations, resulting in award-winning energy savings

801 Grand, Des Moines, Lobby Entrance

801 Grand, Des Moines

Energy modeling, facility assessment, troubleshooting, and combined low/no cost and capital improvements provided long-term benefits for this Des Moines skyscraper

Honoring Our Roots

Sustainable Expansion

From its beginnings over 50 years ago as a small energy consulting firm, under the direction of Dave Grumman and Al Butkus, GBA has grown to include more than 150 professionals in four offices, serving clients throughout North America.

Sustainable engineering remains the bedrock of all we do. From building performance assessments and studies, through design, commissioning services, and post-occupancy engineering analytics, GBA has the expertise you need to create more efficient, economical, environmentally beneficial facilities.

May 1973

Dave Grumman founds Enercon Ltd. at 708 Church Street in Evanston, IL

Dave Grumman Al Butkus

Al Butkus joins the company the following year. Early clients include Hyatt Hotels, the College of Lake County, Springfield’s Lincoln Library, and Mercy Hospital of Chicago.

Sep 1981

First ASHRAE Illinois award

College of Lake County

The firm wins its first ASHRAE award, for a design project at the College of Lake County. Awards for work at Mt. Prospect High School and Rush University Medical Center quickly follow. Al Butkus becomes a principal of the firm.

Nov 1981

GBA opens an office in suburban Milwaukee

Jeff Connor

Jeff Conner becomes the Wisconsin operation’s President and Managing Principal. The move initiates a geographic expansion, and services also greatly expand to a wide range of services, including full MEP design.

Jun 1982

Enercon begins doing business as Grumman | Butkus Associates

Enercon begins doing business as Grumman | Butkus Associates

Chicago-based graphic designer Hayward Blake creates the firm’s distinctive logo. Al Butkus’ role in the firm’s leadership continues to grow; in 1988 he assumes the role of President, with Dave Grumman as Chairman.

Aug 1991

The U.S. Department of Energy honors GBA with the Energy Innovation Award

trib pressroom photo

The Chicago Tribune Freedom Center renovation project also garners the firm’s first ASHRAE Society-level award (industrial facilities, second place).

Sep 1999

GBA Illinois relocates to 820 Davis Street

Four people gathered around a table

The move accommodates steady growth in the Illinois team. A second Wisconsin office, in Madison, is also launched.

Jan 2001

Dan Doyle named President of the Illinois corporation

Dan Doyle

Doyle had joined the firm as one of its earliest employees, in 1980. Al Butkus moves to the role of Senior Principal, with Dave Grumman retaining the Chair position.

Nov 2002

Bob Bayne becomes President of the Wisconsin corporation

Bob Bayne

Bayne had joined the firm in 1988, initially as part of the Illinois office. Jeff Conner retains the role of Chairman.

Jan 2003

ASHRAE gives GBA its first first-place Society-level awards

Hyatt Regency Maui Resort

The awards honored sustainability-oriented design projects at the Hyatt Regency Maui Resort and Spa and the Hyatt Regency Aruba Resort Spa and Casino.

May 2009

Heartland Community College Workforce Development Center receives a LEED certification

Heartland Phase I

The Heartland Community College Workforce Development Center, Normal, IL, is the first building funded by the state of Illinois to receive a LEED certification, with an engineering design by GBA.

Mar 2010

Patient Care Tower at Advocate Lutheran General receives LEED Gold certification

LGH Patient Tower

The new Patient Care Tower at Advocate Lutheran General Hospital, Park Ridge, IL, with engineering design by GBA, receives LEED Gold certification: the first hospital in the Midwest to do so.

Apr 2010

R&D Magazine Lab of the Year recognition

Daniel and Ada Rice Plant Conservation science laboratory at Chicago Botanic Garden

The GBA-designed Daniel and Ada Rice Plant Conservation Science Center, at the Chicago Botanic Garden, is named Laboratory of the Year by R&D Magazine.

Apr 2013

Continuing Care Retirement Community achieves LEED Gold certification

mather south

The Mather South, Evanston, IL, becomes the nation’s first Continuing Care Retirement Community to achieve LEED Gold certification; GBA provided commissioning services.

Oct 2013

GBA opens its New York regional office

Brooklyn Bridge, New York City, symbolizing the opening of GBA's New York Regional Office

Serving a growing demand for commissioning services, GBA opens its New York regional office, in Hoboken, NJ. Also in 2013, GBA’s first LEED Platinum project is certified: Radio Flyer HQ renovation in Chicago, IL, commissioned by the Evanston team.

Jan 2014

Chad Luning becomes President of the Illinois corporation

Chad Luning in his office 2013

Luning had joined the firm in 1991. Dan Doyle moves to the role of Chairman.

May 2014

GBA enlarges its Evanston office


GBA Illinois expands to a second floor of 820 Davis, accommodating growth in the firm.

May 2020

Trend Sumo receives registered trademark status

Trend Sumo data visualization on monitors

Trend Sumo®, GBA’s in-house fault detection and diagnostics platform, receives registered trademark status from the US Patent and Trademark Office; the firm’s Energy Sumo® energy dashboard platform follows in 2022.

Jan 2023

GBA earns Energy Efficiency Service Provider of the Year award

utility awards

ComEd names the company its 2022 Energy Efficiency Service Provider of the Year for the utility’s Energy Efficiency Program; the latest of many utility awards.

May 2023

GBA celebrates 50th anniversary

GBA Hard Hat

Grumman|Butkus Associates celebrates 50 years in business!

GBA Logo

Our Logo

The GBA logo was designed in the early years of the firm to represent both Dave Grumman’s commitment to energy conservation and his love of sailing.

The symbol in the logo is based on the Greek letter “eta,” which is used as an engineering symbol for efficiency; it also recalls the look of sails on Lake Michigan. The stripes symbolize energy exchange. This image reflects the firm’s dynamic approach to every project.


Our Leaders

The firm is guided by a team of highly experienced engineers and management professionals, who are as dedicated to sustainability as they are to customer service. Core principles of collaboration and creativity are part of the company’s DNA, just as they were when GBA was founded in 1973.

Meet Our Leaders

GBA founders and principals