About Us

Our value to our clients is rooted...

Our Markets & Facilities

D2 ENGINEERING provides complete mechanical, electrical, and plumbing design services. We also provide construction services and HVAC and electrical commissioning. Our goal is to provide the client with a reliable, comfortable facility - designed, installed, and commissioned to meet all requirements.

  • Office Buildings
  • Data Centers/Server Rooms
  • Laboratories/Clean Rooms
  • Warehouse Buildings
  • Schools
  • Hospitals and Medical Centers
  • Restaurants
  • Retail Facilities
  • Miscellaneous Structures

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

Mechanical, Electrical, Plumbing Engineering Design Services

mechanical engineering

Mechanical Engineering

Delivering high quality, professional engineering design and construction services.

Electrical Engineering

Electrical Engineering

Mission Critical - consulting services to complete design and construction services; to build a facility from the ground up.

Plumbing Engineering

Solutions that are practical, effective, and proven as well as ideas that are well-honed to the business challenges our clients face

Other Services

Engineering Construction


  • Analysis of Project M/E/P Requirements
  • Comparative Reliability Analysis
  • Life Cycle Studies and Cost Analysis

Design & Pre-Construction

Mechanical/Plumbing systems design and coordination with Architect & Civil Engineer.

Electrical design and coordination with Architect and all other disciplines. SEE MORE NOW!


  • Development of HVAC and Electrical Commissioning Procedures and Specifications tailored for the specific project
  • Building Systems Integration Testing
  • Factory Witness & Acceptance Testing

D2 ENGINEERING is gaining in stature as a respected engineering design company.

Since 2001, D2 ENGINEERING, has successfully completed over 3000 projects

Meet Our Team

About us

D2 ENGINEERING is an experienced engineering design company providing superior engineering design, construction services, and commissioning for new construction, renovations, mission critical and tenant fit outs.

D2 ENGINEERING offers a vast knowledge of design and expertise in commercial facilities. We focus on providing for our client the quality performance achieved in a cost effective and timely manner. The principals and key personnel of D2 ENGINEERING are experienced in mechanical, electrical, and plumbing systems. The principals have over 25 years of experience.

  • Mechanical Engineering
  • Electrical Engineering
  • Plumbing Engineering

Serving the Washington, D.C., Maryland and Virginia metropolitan area.

Our Clients