Electrical, Mechanical, Plumbing Engineering Design Services


About D2 Engineering

Since 2001, D2 ENGINEERING, has successfully completed over 3000 projects for commercial, office tenant, medical, institutional, data centers, mission critical 24/7, government, multi-family high-rises, hotels and recreational facilities.

electrical construction Donegan Engineering Inc, was started in 1989 by James T. Donegan, P.E. Superior Engineers, Inc. was founded in 1996 by Sam Davati, P.E. The two companies merged in 2001 and formed D2 Engineering, LLC. The company provides mechanical, electrical, and plumbing design services to a wide variety of commercial clients, primarily in the Washington DC area.

Our value to our clients is rooted in our own business values and practices.

  • Delivering high quality, professional engineering design and construction services while adhering to a specified schedule and staying within budget.
  • Teamwork approach between our professional staff and the client to really understand the client’s goals and have the resources to act on them.
  • Flexibility and willingness to do business our client’s way by focusing on their unique needs and adding our professional services – bringing value to the partnership, be it anywhere from consulting services to complete design and construction services; to build a facility from the ground up.
  • Solutions that are practical, effective, and proven as well as ideas that are well-honed to the business challenges our clients face on a daily basis – these principles are grounded in experience from having successfully garnered a proven track record with clients whose needs we have served in the past and continue to serve today.

mechanicalWhy D2 Engineering?

- Principals are both professional engineers all with more than 25   years of experience in the field.
- Specializing in Design and Construction Services for Commercial,   Medical and Institutional Facilities.

D2 ENGINEERING is gaining in stature as a respected engineering design company through sustained relationships with our existing clients and creating relationships with new clients.

Key Personnel

Terry Donegan Mechanical Engineer and Sam Davati Electrical Engineer


Senior Electrical Engineer & President: Sam Davati, P.E.

Mechanical Plumbing Design and CS:
Senior Mechanical Engineer & President: James T. Donegan, P.E.

Plumbing Designer: Daljit Gabri, CIPE
(PDF resume)
CAD Draftsman: Tai Shiu

Cad Drafters and Support Personnel:

Shirley Thomas

Sandy Oh

Diana Lopez

Michael Yu

Galene Wong


On the left is James T. Donegan (Terry)
on the right is Sam Davati

19522 Club House Road,   Montgomery Village, Maryland   20886   Ph: 301.208.9576   Fax: 301.208.9405