Director, Oregon Zoo

-- Heidi Rahn

“Equilibrium is a team player, committed to keeping a project on schedule and creative when presented with challenging design scenarios.”  

AT EQUILIBRIUM ENGINEERS, we believe that a well-balanced team is essential to both delivering service to our clients and building a resilient business. The size of our firm and diversity of backgrounds of our staff allow us to provide experience-based service in a timely and affordable fashion. We bring a collaborative, creative approach to each new project, and have the depth of knowledge to handle projects of all sizes and degrees of complexity.

Ed Quesenberry, S.E. is the Founding Principal of Equilibrium Engineers LLC. Ed has over 30 years of structural engineering consulting experience on a broad range of building types, including civic, commercial, educational, medical and housing facilities in California, Oregon and Washington.

Ed graduated from California Polytechnic State University in San Luis Obispo with a Bachelor of Science degree in Architectural Engineering. He is a registered Civil and Structural Engineer in most western states.

Supporting and advancing the structural engineering profession is a passion of Ed’s. He has served as President of the Structural Engineers Association of Oregon (SEAO), is a Past President of the Board of Directors of the National Council of Structural Engineers Associations (NCSEA), and is a driving force behind NCSEA’s We SEE Above & Beyond Campaign www.weseeaboveandbeyond

In his spare time, Ed enjoys exploring the Pacific Northwest on his road bike or can be found knee deep in a river hunting for any fish that will take his fly.




Leif Erickson, S.E. is the Managing Principal of Equilibrium Engineers, LLC. He is a registered Structural Engineer in Oregon, and Professional Engineer in both Oregon and California. Leif joined Equilibrium Engineers in 2021, bringing with him over 10 years of structural engineering consulting experience in various project types including residential, commercial, medical, educational facilities, seismic retrofit, as well as temporary works and demolition.
Leif has a Master of Engineering degree from Portland State University, focused on structural engineering. At Equilibrium Engineers he is responsible for the coordination of projects from Schematic Design through Construction Administration to meet the goals and budgets of his clients. He has developed a strong background in Building Information Modeling (BIM) and strives to bridge the gap between engineering design and document creation in the most efficient way possible to meet project deadlines and budgets.

Leif enjoys spending time with his family outside of work.  He inherited a mini horse farm through his wife where he becomes the horse show assistant when she shows them in regional competitions.  He also enjoys SCUBA diving and exploring the underwater world.



Leif Erickson, S.E.

JoMarie Farrell, P.E. is an Associate with Equilibrium Engineers LLC. She is a licensed PE in both Oregon and California. JoMarie has over 29 years of structural engineering consulting experience on a broad range of building types, including housing, hotel, commercial, medical, educational, transit, and government facilities in Oregon, Washington, and Wyoming.

JoMarie has a Bachelor of Science degree in Civil Engineering from The University of Portland. At Equilibrium Engineers she is responsible for the coordination of projects from Schematic Design through Construction Administration. In addition, she is responsible for adhering to the budget and schedule parameters of each project. She serves as the day-to-day contact with the client on all of her projects. Ms. Farrell joined Equilibrium Engineers in 2008.

JoMarie started working in construction in 1987—as an on-site administrative assistant to the architect on the Portland Center for the Performing Arts in Downtown Portland. She loved the built environment so much that she returned to school to study civil engineering with an emphasis on structural design.

JoMarie enjoys volunteering for the Structural Engineers Association of Oregon (SEAO) and is a former Director of the Board. She is the current newsletter editor for their monthly publication, and she enjoys assisting with SEAO’s annual awards program.



Jomarie farrell, p.e.

Mark Forster is the BIM Manager with Equilibrium Engineers, LLC and is responsible for AutoCAD drafting and Revit modeling. He is also responsible for the setup and execution of Autodesk and add-in products within the firm, and manages our company’s BIM standards. Mark joined Equilibrium Engineers in 2017.

Starting on the path of becoming a computer programmer, Mark eventually took more of an interest in the drafting field and eventually graduated from PCC Sylvania with an Associate degree in Architectural Drafting. His skills as a designer and CAD technician vastly grew over time. His expertise began by learning the art of hand drafting, extended to learning AutoCAD Version 2.5, and has continued with every new software release. Throughout his 30 year drafting/designer career, his knowledge has expanded to multiple platforms, including DCA, Land Desktop Development, Civil 3D, MicroStation, and Revit. 

When he’s not building 3D Revit models, Mark enjoys wood-working and small remodeling projects to express his passions outside of work.


BIM Manager


Sam Bucich, P.E. is a Project Engineer at Equilibrium Engineers. She is a licensed PE in Washington with 5 years of structural engineering experience ranging from new construction to deep foundation design in the US, Canada, and Australia.

Sam has a Bachelor of Science degree in Civil Engineering as well as a Master of Science degree in Structural Engineering from Washington State University. At Equilibrium Engineers she is responsible for the coordination of projects from Schematic Design through Construction Administration to ensure that the specific needs of each client are met on time and within their budget.

Outside of work Sam enjoys reading, crafting, riding her motorcycle, and trying out all of the great food in the area. But her favorite thing to do is just spend time with her husband and their chihuahua Jeffery.


project engineer

Sam bucich, p.e.

Brennen Johnson is a Structural Designer with Equilibrium Engineers, LLC. He joined Equilibrium Engineers in 2023 as an entry-level designer. Brennen graduated from Washington State University in 2021 with a Bachelor of Science in Civil Engineering. He worked for a non-profit teaching engineering concepts to underrepresented communities before joining the Equilibrium Engineers team.

Outside work, Brennen can usually be found at a gym playing basketball or enjoying nature on the top of a mountain.


Structural Designer

Brennen Johnson

All rights reserved.

8625 SW Cascade Ave
Suite 605
Beaverton, Oregon