Since 1910, LLI Engineering has been consistently recognized for providing top-quality engineering design services. 

Completing more than 10,000 major projects, representing over $3.5 billion in construction spending, with excellent client reviews, confirm why LLI has such a long and rich history. Our core values include providing straightforward communication, meticulous contract management, cost effective construction, and business driven client solutions.

Located near Pittsburgh, Pennsylvania, LLI Engineering has completed projects in over 20 different states. We specialize in commercial, critical facilities, infrastructure upgrades, green building design, energy conservation modifications, project engineering, and engineering estimates. LLI provides electrical, mechanical, piping, and structural engineering services.