50th Anniversary

Facebook Twitter LinkedIn

Phone Icon (816) 350-1473



12/03/1931 – 08/27/2022

Clarence Mabin

It is with sad hearts that we announce the passing of Clarence Mabin, former owner and president of Custom Engineering. 

Clarence began his working career as a dining car waiter for the Burlington Railroad in Lincoln, Nebraska. In 1954, Missouri integrated its public schools and Clarence had the opportunity to enroll at St. Joseph Junior College in their pre-engineering curriculum. Clarence graduated in 1958 and was listed academically in the top 5% of his class. 

Clarence applied and was accepted at the University of Missouri, College of Engineering in Columbia, Missouri. In 1961, he received a Bachelor of Science Degree in Civil Engineering and became the first African American to complete this curriculum. In 1998, one of his first instructors would nominate him for the highest honor given to a Missouri engineering graduate. 

Clarence Mabin was a member of the Civil Engineering Academy of Distinguished Alumni and through that group; he supported more than $400,000 in endowed scholarships for transfer students. In addition, as a member of the Dean’s Engineering Advisory Council, Mr. Mabin regularly had met with the Dean of the MU College of Engineering, to give input on the direction of the college. 

In 1999, Clarence Mabin received the college’s highest honor, the Missouri Honor Award for Distinguished Service in Engineering, and in 2004 Mr. Mabin received the MU Alumni Association’s highest honor, the Faculty-Alumni Award. Clarence was nationally known for his expertise in poles, highway signage, and outdoor lights. He designed the lighting foundations for the light poles at Memorial Stadium in Columbia, Missouri. Mr. Mabin considered the knowledge he gained at MU the foundation for a successful career that has led him to senior engineering positions in Nebraska with previous employers. 

Complimenting these skills was a personal and company objective to develop young minority technical and professional personnel. Based on his commitment and aggressive marketing approach, he received the 1996 Minority Enterprise Development Award, the Kansas City Chamber of Commerce Top 10 Business Award for 1998, A Harmony Hero Award in 1998, and has been featured in publications such as the Kansas City, Missouri Star Newspaper, the University of Missouri Engineering Alumni Publication and the Kansas City Business Journal. 

In 2017, Clarence sold his remaining stock in Custom Engineering and moved back to Nebraska to be closer to his family

Kansas City Business Journal Features CEO Joe Davis

Twenty to Know - Engineering

July 9, 2021

On July 9, 2021 the Kansas City Business Journal featured 20 people in engineering. The 20 to Know list is filled with key people and influencers. We are proud to be one of the few. The excerpt below is from the full Business Journal article, found here.

Joseph Davis
Custom Engineering

Davis has led Custom Engineering since 1999, balancing responsibility for overseeing big projects as well as Custom’s business operations, including everything from budgeting to HR. The firm has grown to rank No. 20 on the Kansas City Business Journal’s Minority-Owned Businesses List. And it has continued to grow, expanding in St. Louis and acquiring a nine-employee firm in Columbia in 2019.

The mechanical and electrical engineering company has won a long list of high-profile jobs, including work on Kansas City International Airport, the Kansas City streetcar extension and the Major League Soccer stadium in St. Louis.

KC Biz Journal Twenty to Know

Joseph Davis


St. Louis MLS Stadium Support Facilities

March 4, 2021

St. Louis City SC is the Major League Soccer team set to make its home in St. Louis in 2023. Custom Engineering is working with ME Group and HOK to provide mechanical, electrical, and plumbing engineering design for the Training Center, Administration Building, and Maintenance Building south of Market Street. A full press release and renderings of the stadium and support facilities can be found here

The Kansas City Streetcar Extension is Happening!

December 9, 2020

Custom Engineering is working with HNTB to provide mechanical, electrical, and plumbing enigneering design for the expansion of the vehicle maintenance facility. "The Federal Transit Administration (FTA) and Department of Transportation (DOT) have officially recommended that the KC Streetcar Main Street Extension to UMKC receive the full federal funding requested to build the project under the FTA’s New Starts Capital Investment Grants (CIG) Program." Read the full press release from the KC Street Car here.

Singleton Yard

COVID-19 Response

March 23, 2020

COVID-19 - Our Commitment to Employees, Partners, Clients, and Community
Our Action Plan
With the ongoing developments of COVID-19, we hope you and those closest to you are remaining healthy and unaffected.

In light of the seriousness of the current situation, we have activated our Business Continuity Plan (BCP) and as a result are operating at normal capacity with no interruptions or changes to commitments to deadlines and service to our clients.

At both Custom and Timberlake Engineering, the health, safety, and wellbeing of our employees, partners, clients, and communities are our top priorities.

Commitment to Employees
To ensure we are providing a safe and healthy work environment, we are closely following the guidance of the Centers for Disease Control (CDC) and the World Health Organization (WHO) and have taken necessary precautions by cancelling all nonessential travel and discouraging staff from attending external events and conferences, and practicing social distancing.  We will continue to use virtual meetings and teleworking as is increasingly becoming our common practice.

Our Commitment to You
We understand the concern and uncertainty surrounding the Coronavirus (COVID-19) and we are committed to providing our clients and their employees with the very best service possible during this difficult period. This communication is intended to inform you of how we are meeting this challenge head on: 

  • 90% of our employees are now working at home/remotely until this crisis passes. By this Monday (March 23), this percentage will rise to 100% although we will have skeleton crews at each office throughout the week as necessary to respond to our commitments.  These measures apply to all Custom Engineering offices, including Custom Engineering HQ in Independence, MO, Custom Engineering-St. Louis, and Timberlake Engineering in Columbia MO.
  • We will continue to monitor both local and national sources to ensure we keep abreast of the most current information available. With this in mind, our procedures and approach to this pandemic is subject to change as recommendations and requirements change.   

While we will remain fully operational and are working hard to minimize the negative impact on service and quality to our clients, we want you to know we can meet this challenge.

Thank you for your support and trust in Custom Engineering and Timberlake Engineering.  Working together, we will overcome this challenge to our communities and country.


Joseph T. Davis, PE

President & CEO

Custom Engineering

Custom Engineering Adds Nine Employees with Acquisition

November 5, 2019


Custom Engineering, a mechanical and electrical engineering design firm, has acquired Timberlake Engineering of Columbia, MO. The acquisition was made final on October 24, 2019. This strategic move will give Custom Engineering and Timberlake Engineering a greater presence across the state with firmly established offices in the Kansas City, St. Louis, and Columbia areas. With the addition of the Columbia staff members, all offices increase their capacity for larger and more numerous projects to serve their respective local markets. The acquisition further meets the demands of all clients to increase capacity as they would like to award more work; a proving testament to this company’s dedicated team of professionals focused on professionalism, efficiency, and responsiveness.

Timberlake Engineering was founded in 1999 and is a full-service mechanical/HVAC, electrical, lighting, and plumbing, LEED consulting engineering firm, with a diverse experience base that mirrors that of Custom Engineering. The firm was named Columbia Business Times’ TOP OF THE TOWN “Top Engineer” in 2015.

In regards to the acquisition, Custom Engineering CEO, Joseph Davis, PE, says, “Timberlake’s outstanding team of professionals and strength of reputation made them very attractive as a complement to our existing team. It’s all about the people; when we began to learn of the outstanding client satisfaction, repeat business, and dedicated team who do things the right way, we knew it was a great fit. The culture of quality and responsiveness to meet client demands is taken very seriously, so it quickly became evident the Timberlake Team was the right move.” It is important to iterate that there will be no major changes for existing client relationships. Custom Engineering and Timberlake Engineering were built on client relationships, and Custom Engineering intends to continue that principle in the Columbia office.

About Custom Engineering, Inc.: Custom Engineering, a certified MBE/DBE firm since 1992, specializes as a mechanical, electrical, and plumbing system design consultant for construction and rehabilitation projects in commercial and industrial facilities. Custom Engineering provides a knowledge pool of diversity for team collaboration on project strategies and scopes requiring multiple disciplines and ranging in size from small rehabs to multi-million-dollar facilities. The not all inclusive list of markets served are aviation, higher education, water/wastewater, healthcare, transportation, utilities, city, state, and federal.

Delbert Haff Fountain

Delbert Haff Fountain Re-Opens for Fountain Day 2019

April 16, 2019

Kansas City's Delbert Haff Fountain, located at Meyer Boulevard and Swope Parkway, was originally dedicated as a simple mirror pool in 1940. In 1966, the vertical jets were added. It was decided in 2015 that renovations needed to be made to the fountain and surrounding area. The concrete pool basin was delaminated and leaking, many of the pool light fixtures were not functional, moisture infiltration at the existing electrical vault near the pool was a recurring issue, and various plumbing and electrical fountain components were approaching the end their anticipated useful lifespans.

As part of the renovation project, the pool depth was decreased from 3 ft to 18” maximum, providing both water conservation and public safety enhancements to the site. The water feature in the pool was increased from three jets to seven, adding visual punch to the wide open site. To facilitate installation of new, larger capacity fountain pumps and a pool filtration system, a new concrete equipment vault was installed in place of the existing electrical fault. Configuration and layout of the new vault accommodates access and maintenance to the new equipment. Renovated fountain equipment items incorporated into the project by our design team include a new ship’s ladder into the vault (in lieu of a perpendicular ladder), new electrical transformer, meter and disconnect within line-of-sight of the fountain, fountain fill water flow control, and the inclusion of skimmer baskets in the pool filtration/treatment system. The new LED fountain lights are RGBW with color sequencing capabilities.

The fountain officially re-opened at the conculsion of the Fountain Day 2019 ceremony on April 16, 2019.

CEO Featured in "Thinking Bigger" Business Magazine

July 9, 2018

Custom Engineering is a certified minority-owned enterprise. Recently, CEO, Joe Davis, P.E. , LEED AP, spoke with Thinking Bigger Business Media, Inc. about why we obtain and maintain our certifications. ...

CEO Joe Davis said the mechanical and electrical engineering firm’s certifications related to being a minority-owned company helped land it such a major role in one of the city’s largest public infrastructure initiatives. “It’s highly unlikely we would be involved without certification,” Davis said. “Without it, large firms would most likely get all the work.”...“Certifications have been essential to our success in getting access to clients and contracts,” he said. “It’s not a guarantee, but it helps get your foot in the door.”

Click here for the full article.

KCI Taxiway B Rehabiliation is Underway!

August 8, 2018

The crews out at Kansas City International Airport are making progress on Phase II of the rehabilitiaon of Taxiway B. One of Custom Engineering's own is serving as resident engineer to oversee the installation of the airfield lighting and other electrical items. The project is set to be complete by December 1, 2018.

Taxiway B reabilitation

Our St. Louis Office Has Moved!

Our St. Louis team has moved into a new office space. Our new location is just south of downtown. The 7700 sqft facility has 6 offices, 21 workstations, a conference room, large training room, breakroom, and 21 parking spaces. We are excited about our growth and are getting settled in the office. You can find us at 1552 S. 7th St., St. Louis, MO 63104. Our phone number remains the same.

STL Office

Erin Decker

Erin Decker Promoted to Marketing Coordinator

January 4, 2018

Custom Engineering is pleased to announce that Erin Decker (formerly Project Assistant) has been promoted to Marketing Coordinator. Erin has been the company for nearly five years. In this time, she has been instrumental in helping us win projects by preparing resumes, project descriptions, proposals, and coordinating with clients. She also has the responsibility of website maintenance, social media, and client engagement. Erin often receives compliments from our clients on her prompt response to their request for information critical for meeting submittal deadlines. Congratulations, Erin!

Custom Engineering Supports the Edgemoor Team Selection

December 19, 2017

 Joe Davis, CEO of Custom Engineering, is excited about Kansas City's new terminal.  We are even more excited in the role we will play designing it.  A project of this scale doesn't come around to often and the impact on the community will be phenomenal. We have had access to decision makers and challenged to grow our company with their support.  We believe the community engagement and enhancement proposal the Edgemoor Team has presented to KCMO will be a catalyst for hiring and strengthening of MWBE professional services firms.  Time is of the essence and continued negotiations between KCMO and Edgemoor is strongly encouraged.

 Joe Davis

Society of Marketing Professional Services (SMPS) Mentor/Protege Program

Society of Marketing Professional Services (SMPS) Mentor/Protege Program

November 16, 2017

The 2017-2018 SMPS Kansas City class of mentors and protégés met on November 7 to kick-off the year and discussed schedules, roles and responsibilities and suggestions on how to enhance the professional relationship for the year. Custom Engineering's marketing coordinator, Erin Decker, is participating this year as a protégé. "I am excited to learn from someone who knows the industry so well and is willing to pass some of that knowledge on to me. I hope to learn just a fraction of what she does so that I can apply it to my own career and help my company move forward."

KCI Facility Shop Complex Nears Completion

November 16, 2017

Custom Engineering's team of mechanical and electrical engineers made a final visit to the KCI Facility Shop Complex to run through the final punch list for our scopes of work. in the photo to the right, mechanical engineer, Jeremy Walker, is cross referencing drawings with new ductwork and equipment and making sure all equipment shown on drawings matches the building layouts. 

Custom Engineering provided mechanical and electrical design services for a new maintenance complex. The main 15,000 sq. ft. facility includes administration offices with support areas, as well as individual shops including carpentry, equipment repair, metal, welding, paint and associated support areas including tool/part/equipment storage areas.

Electrical design services include power, lighting (interior and exterior), lightning protection, fire alarm, CCTV/access control systems, communications and data/IT design. Mechanical and plumbing design services comprised the 7,000 square feet of administration space to be conditioned with a variable refrigerant flow (VRF) system for energy savings to help meet LEED Gold standards. The outside air requirements utilize energy recovery units to recover exhaust and return energy. The remainder of the shop will be ventilated with wall propeller fans and heated with high efficiency gas fire unit heaters. Low flow plumbing fixtures will be used throughout. Ancillary systems include a paint booth, welding hood system, wood shop dust collection, emergency eyewash & safety showers and a truck dock lift.


KCI Facility Shop Complex

Meyer Circle Seahorse Fountain Flows Again

Meyer Circle Seahorse Fountain Flows Again

October 6, 2017

The Meyer Circle Seahorse Fountain is nearly complete. The water was turned back on for a test run on October 6, 2017. The fountain will be drained for a final punch list check on Monday, October 9, 2017.  Walter P Moore is the architect for the project.

 Custom Engineering provided MEP condition assessment, improvements design, and construction administration services for the renovation of the Meyer Circle Sea Horse Fountain. Originally constructed in 1925, this fountain has evolved into a Kansas City landmark. The fountain was in need of extensive repairs and had been dry since the fall of 2015. Underground vault flooding, damage to the fountains pumps, motors, and electrical systems, and leaks in the fountain pool were among the major obstacles to reliable fountain operation.

The project was completed in two phases. For Phase I Custom Engineering completed an assessment confirming existing conditions and compiled a study/report with recommendations for improvements. A preliminary construction cost estimate was also provided for budgetary reference. Phase II construction work included concrete and masonry wall repairs, fountain floor and wall waterproofing, site improvements, and complete replacement of the main electrical service, pump vault, pool plumbing and pool lighting. Custom Engineering provided a design for the new pump vault, pool piping and nozzles, pool lighting systems, and main electrical service.