History of L & S Energy Services


L&S Energy Services is a customer-focused, energy efficiency driven organization. We guide each of our customers in an objective and impartial manner, assisting them in selecting the best path toward meeting their energy efficiency goals. We seek to educate our customers about the economic benefits of energy efficient buildings and/or systems and thereby help create a more energy independent society through energy conservation and energy efficient building improvements.

missionDennis Landsberg was a founding principal of the Fleming Group and served as a Vice President from 1977 to 1986. The Fleming Group performed energy efficiency studies, end-use metering, monitoring and analysis of advanced energy technologies and evaluation of utility energy efficiency programs. Work included all of the data collection for ELCAP, a Pacific Northwest Labs project that was the first major end-use metering project in the US. The Fleming Group also prepared the DOE Technical Support Document that put for the DOE-2 computer program as the Standard Evaluation Technique.

In 1985 he started Landsberg Engineering, P.C. as an engineering affiliate of the Fleming Group. In 1986 he became President of the Fleming Group. During this period the ASEAM Energy Analysis Computer Program was developed, an updated version of GSA’s Energy Analysis Guide for Architects and Engineers was written and analysis was performed on PG&E’s ACT2 project.

In 1993, the Fleming Group was sold and Dennis Landsberg began an energy efficiency practice under Landsberg Engineering, P.C. Notable accomplishments included energy studies of US Embassy Facilities in 30 countries, evaluation of the first super ESPC project at Fort Polk, LA for Oak Ridge National Laboratories and end-use metering of data centers for Lawrence Berkley Laboratories.

New Picture for L&S Website
L&S President Dennis Landsberg, PhD
inducted to AEE Energy Managers Hall of Fame (2015).

In October 2006 Ron Slosberg joined and L&S Energy Services, Inc. was formed. The firm has grown and continually increased its energy analysis capabilities. Highlights include energy modeling of three new US Embassy facilities, ASHRAE’s Energy Efficiency Guides for Existing Commercial Buildings and development of the NYSERDA Combined Heat and Power Program. Since 2010, L&S has worked extensively with National Grid and assisted in the development of their Custom Express measures.

L&S also has a strong presence on the national stage. Ron Slosberg is Regional Vice President of the Association of Energy Engineers and Dennis Landsberg chaired the recent publication of ASHRAE Guideline 14 – Calculation of Energy Demand and Water Savings. He is a voting member of the ASHRAE standing special project committee for Standard 100 – Energy Efficiency in Existing Buildings, SPC211Building Energy Audits and is currently Secretary of ASHRAE Technical Committee 7.6 – Building Energy Systems.


Corporate Headquarters

L&S Energy Services, Inc.
58 Clifton Country Road
Clifton Park, NY 12065
Phone: 518.383.9405
Fax: 518.383.9406

Metropolitan New York City

L&S Energy Services, Inc.
Phone: 518.383.9405

Las Vegas, Nevada

L&S Energy Services, Inc.
c/o Dennis Landsberg
35 Via Paradiso Street
Henderson, NV 89011
Phone: 702.280.5742

Columbus, Ohio

L&S Energy Services, Inc.
c/o Yigit Guctas
397 Keith Way
Lewis Center, OH 43035
Phone: 614.403.9354

Contact L & S Energy Services

To learn more about our company, send us a message or call 518-383-9405.