M. Dennis Knight has over 40 years’ experience in the design, construction, operation and maintenance of high performance buildings.  He is an ASHRAE Director at Large, an ASHRAE Fellow (FASHRAE) and ASHRAE Distinguished Lecturer.  Mr. Knight’s expertise lies in Building Information Modeling (BIM) and Integrated Building Design. He currently chairs both the ASHRAE BIM Multi-disciplinary Task Group, where he is the liaison to the International Building Smart Alliance, and the annual ASHRAE Energy Modeling Conference.

Mr. Knight founded Whole Buildings Systems, LLC, in 2010 after having owned both an engineering firm and a construction company, and most recently as a Principal at Liollio Architecture in Charleston, South Carolina. He is a registered mechanical and fire protection engineer, an ACG certified Commissioning Authority, an ASHRAE certified Building Energy Modeling Professional (BEMP), a LEED NC and EB O&M Accredited Professional and a Building Performance Institute (BPI) certified Building Energy Analyst (BA) and Envelope Professional (EP).

During his career, Mr. Knight has commissioned hundreds of new buildings and audited or retro-commissioned over 100 million square feet of existing commercial, federal and industrial building stock.  He introduced Revit 3D drawing to a 30 person architectural firm and provides whole building energy simulation analysis using Trane Trace 700. 

Mr. Knight frequently lectures in the US and abroad on high performance building tools and technology and has authored numerous publications and white papers on a variety of technical topics.  He has developed curriculum and teaches on BIM, Integrated Building Design, Life Cycle Cost Analysis, ASHRAE 90.1  and IECC energy code compliance, energy management for historic structures in hot and humid climates, and energy modeling and commissioning of energy using systems.

Mr. Knight’s vision for Whole Building Systems is to assist owners, architects, contractors and facility management professionals to adopt new tools and process improvement strategies that will result in the design, construction, operations and maintenance of high performance building that meet the triple bottom line.

Mr. Knight holds a Bachelors of Science in Physics from the College of Charleston.


  • National Institute of Building Science, Whole Building Design Guide; HVAC Web Pages, Co-Author; www.wbdg.org

  • ASHRAE Journal Article, May 2006 “Specifications for Integrated Building Design”; Co-Author

  • ASHRAE Applications Handbook 2007 Edition – Chapter 57 “Integrated Building Design”; Subcommittee Chair and Co-Author

  • ASHRAE Journal Article, September 2008 “Teams Contracts & BIM”; Author

  • ASHRAE Journal Article, June 2010 “BIM for Energy Modeling”; Co-Author

  • City of Charleston Sustainability Plan (also known as “The Charleston Green Plan”), Co-Author

Honors and Awards:

  • ASHRAE Director at Large – 2014

  • ASHRAE Fellow - 2012

  • City of Charleston Stewardship Award - 2010

  • ASHRAE Distinguished Lecturer - 2008, 2009, 2010, 2011

  • ASHRAE Regional Service Award - 2009

  • USGBC SC Chapter Annual Leadership Award - 2008

  • AIA Charleston Chapter Special Leadership Award - 2008

  • ASHRAE Research Promotion “Top Dog” Award - 2004 and 2005

  • Charleston Joint Engineers Society Engineer of the Year Award - 2002-2003

  • Past President Charleston Chapter ASHRAE - 1986 and 2000

  • Chairman, Construction Board of Adjustments and Appeals, Town of Mt. Pleasant, SC - 1999

Susan E. Collins  |   Principal and Chief Operating Officer


Ms. Collins has 30 years' of strategic planning, marketing and product development in the technology, communications and energy sectors. Prior to joining WBS, Ms. Collins held executive level positions as Senior Vice President of the DIRECTV satellite service, where she helped to launch the product and Vice President of Marketing for Virgin Mobile USA, Richard Branson’s youth oriented mobile phone start-up in the US.

As Chief Operating Officer for Whole Building Systems, Ms. Collins is responsible for strategic planning, operations and business development. On the client side she assists clients in developing strategic energy management plans and writing design requirements and standards. Using EPA Portfolio Manager she sets performance criteria through benchmarking and analysis, prioritizes energy conservation measures and assists clients in attaining energy certification including LEED and the Energy Star Label. Ms. Collins assisted the Charleston County School District in the development of design requirements for their $800 million new construction and major renovation 2016 capital project program. A LEED Accredited Professional, she assisted the City of Charleston with the creation of a sustainability plan and the launch of CharlestonWISE, the City’s residential energy efficiency program. Ms. Collins is an Accredited South Carolina Energy Manager and holds several certifications from the Building Performance Institute (BPI) including Building Analyst and Envelope Professional. She holds a Masters of Science in Historic Preservation from the Savannah College of Art and Design and assisted in the development of BPI training curriculum for the proper weatherization of historic buildings in hot and humid climates. She is a voting member of ASHRAE GPC-34, a committee that is writing a standard of care for energy efficiency in historic structures. She is an Advisory Board member for the American College of the Building Arts in Charleston, South Carolina, currently assisting them with their 2016 - 2020 Strategic Plan. She is also a graduate of ACBA with an AAS in Architectural Stone and Preservation Masonry, and teaches as an adjunct for the College on an as needed basis.  She recently earned her WELL AP accreditation. 

Joel H. McKellar | Director of Building Performance Services



Mr. McKellar has spent over 12 years of his career optimizing the performance of buildings from design through occupancy. He has extensive experience in sustainable design consultation and project management (7+ million square feet), commissioning (125,000+ sf), energy management and auditing (12+ million sf) and LEED and Living Building Challenge certification administration (5+ million sf). At Whole Building Systems, Mr. McKellar provides commissioning services, high performance design consulting and will play a leadership role in advancing the definition of sustainable buildings to include occupant health, well-being and productivity.

Prior to joining WBS, Mr. McKellar served as Associate Director of Green Building Services at Harvard University where he was responsible for strategic planning efforts, policy guidance and direct project management of programs associated with sustainable design, construction and operations of Harvard University's 27 million square foot campus. He co-authored the Strategic Sustainability Plan at the Harvard Kennedy School of Government, updates to the University-wide Green Building Standards, and was responsible for technical reviews of the Harvard Green Revolving Fund and management of associated life cycle costing tools.  Prior to his work at Harvard, Mr. McKellar was a Research Strategist for the architectural firm LS3P ASSOCIATES LTD. in Charleston, SC. He currently sits on the Energy and Atmosphere Technical Advisory Group and the Market Leadership Advisory Board for the US Green Building Council.  



Kimberly G. Ledwell, EIT | Mechanical Design Services Coordinator


Ms. Ledwell has several years’ experience in the  design and specification of HVAC systems.  Prior to joining WBS she worked at NEWCOMB & BOYD LLP in Charleston where she produced design documents and analytical reports for projects in higher education, healthcare, compounding pharmacies, central energy plants, hotels, and other commercial buildings.

At WBS, Ms Ledwell provides MEP design and support including field site investigations, design layout and drawings, load calculations, equipment and system schedules, basis of design documentation and initial pricing estimates.  She is responsible for project management services from design through construction contract administration.  She is currently working on the design for the total HVAC replacement for the 200,000 sf St. John’s High School in Charleston.  She also provides design reviews and field support services for commissioning projects. 

She holds a BS in Physics and a Masters degree in Mechanical Engineering, both from Clemson University in South Carolina.