Energy For Home Builders, HVAC Installers, and Homeowners.

Welcome To CLE

With an ever-growing demand for energy efficiency in all aspects of life, we have a variety of services to meet all your energy needs.


Trusted by Fortune 500 Companies
CLE has completed and certified over 13,000 Energy Star homes! Our services include:


MEP Design Services, HERS Verifications, Energy Star Certification, Build-It-Green, Residential Title 24, CalGreen Inspections, IECC-Remrate Energy Calculations, and Energy Consulting.

All Services


T24 lighting Calculations, T24 Envelope Calculations, T24 Mechanical Calculations.

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MEP Design

Work with CLE for mechanical, electrical, and plumbing design services.

All Services

Mechanical/ HVAC Design

Choose the CLE team for the design of your next HVAC system.

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Electrical Design

CLE can provide you with single line diagrams, load calculation and electrical layouts

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Plumbing Design

Plumbing Design, including Sewer, waste, vent, and drain, and isometric layouts.

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Testing Verifications

CLE can provide you with a wide variety of inspection and compliance documentation services.

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Energy Calculations

Your team at CLE offers detail-oriented, precise Title 24 energy in California and Energy calculations across the country saving you on construction cost

All Services

About CLE

Founded in 1988 by company president Bill Lilly, CLE provides energy consulting services to the new home, existing‑home, multi‑family, and commercial building markets. 

Holding a California State General Contractor's License, as well as licenses for mechanical and insulation contracting, CLE is a certified Home Energy Rating Systems provider by Calcerts, Inc., California Energy Registry, and RESNET. CLE has provided engineering services throughout California.


Licensed Engineer on Staff

Built It Green Certification

Energy Efficient Mortgage Program (EEM)

HERS Testing

Green Built Homes of America ©

California Energy Registry


National Comfort Institute

Accredited Resnet Rating Provider for Arizona & Nevada

State License Matrix


Get In Touch With CLE