Joseph Lstiburek's picture
Ph.D., P.Eng., ASHRAE Fellow
Principal, Building Science Corporation

Joseph Lstiburek is the founding principal of Building Science Corporation.  Dr. Lstiburek’s work ranges widely, from providing expert witness testimony to overseeing research and development projects, to writing for the ASHRAE Journal and  Dr. Lstiburek’s commitment to advancing the building industry has had a lasting impact on building codes and practices throughout the world, particularly in the areas of air barriers, vapor barriers, and vented and unvented roof assemblies.  For example, his work with industry partners through the Department of Energy’s Building America program led to significant research into the wetting and drying of walls and ultimately to a major code change relaxing the requirement for vapor barriers in the International Residential Code.

Dr. Lstiburek is also an acclaimed educator who has taught thousands of professionals over the past three decades and written countless papers as well as the best-selling Builder Guides.  Fittingly, the Wall Street Journal has described him as "the dean of North American building science."  He has a joy for telling tall tales to his protégés and audiences.

Dr. Lstiburek holds a Bachelor of Applied Science in Mechanical Engineering, a Master of Engineering in Civil Engineering, and a Doctor of Philosophy (Ph.D.) in Building Science.  While still an undergrad, Dr. Lstiburek worked as a residential construction manager; during his Master’s degree, he developed the Air Drywall Approach to air barriers.  Other formative experiences include working on the Canada-wide Super Energy Efficient Housing R-2000 program and serving as senior engineer on commercial construction projects for Trow in Toronto.  Dr. Lstiburek founded BSC in 1990 with his business partner Betsy Pettit, and he has been a key figure in establishing BSC as one of the most influential, innovative, and respected building science firms in North America.

View Joseph Lstiburek's Resume

View Joseph Lstiburek's Master's Thesis

View Joseph Lstiburek's Doctoral Thesis

View Joseph Lstiburek's Paper "A New Approach To Affordable Low Energy House Construction"

Betsy Pettit's picture
M.Arch., FAIA
President, Building Science Corporation

Betsy Pettit is the president of Building Science Corporation and is a registered architect with over 35 years of professional experience in the design and renovation of residential, commercial, and institutional buildings.  With a particular passion for and commitment to environmentally responsible design, Ms. Pettit managed Building Science Corporation’s role in the Department of Energy’s Building America project for the past twenty years, which has involved the design of over 2,000 high performance houses throughout the United States.

Consistent with her philosophy that environmental responsibility ought to also be economical, Ms. Pettit has done extensive work to advance the building industry in the area of energy efficient affordable housing, partnering with Habitat for Humanity, as well as developers and builders across the United States.  She is the former Director of Modernization and Redevelopment in the public housing division of the Commonwealth of Massachusetts Executive Offices of Communities and Development, where she oversaw over $120 million of building improvements to Massachusetts’ 40,000 units of public housing.

Ms. Pettit has given seminars on the subject of healthy and environmentally responsible housing to builders and architects across the country, and she has contributed to many procedural and technical manuals and papers to guide designers and contractors in the area of high performance design.  She has also served as chair of the Northeast Sustainable Energy Association (NESEA) Buildings Conference, where BSC staff members are frequent presenters.

Ms. Pettit holds a Bachelor of Applied Science in Environmental Design from Miami University and a Master of Architecture from North Carolina State University.  Based on Ms. Pettit’s “notable contributions to the advancement of the profession of architecture,” she was elected to the College of Fellows of the American Institute of Architects in February 2008. 


Bachelor of Environmental Design, Miami University, Oxford, Ohio

Master of Architecture, North Carolina State University, Raleigh, North Carolina

Professional Registrations     

Registered Architect: Massachusetts, Georgia, Maryland, Ohio, Oklahoma, New Hampshire

Professional Certifications     

National Council of Architectural Registration Boards (NCARB) Certification

Professional Affiliations     

Fellow, American Institute of Architects (AIA)

Member, American Institute of Architects (AIA)

Committee on the Environment, American Institute of Architects (AIA)

Member, Boston Society of Architects (BSA)

Past Co-Chair, Indoor Air Quality Committee, Boston Society of Architects (BSA)

Past Board of Directors, Energy and Environmental Building Association (EEBA)


Peter Baker's picture
B.Sc., P.Eng., P.E.
Senior Associate, Building Science Corporation

Peter Baker is an expert in building forensics and the building enclosure design of residential, commercial and institutional buildings, particularly with respect to energy efficiency, durability, constructability, and water management.

Mr. Baker conducts field investigations of existing buildings with problems such as leaks, rot, mold, decay, odors, poor indoor air quality, and uncontrolled humidity.  With over a decade of first-hand insight into the realities of construction, Mr. Baker determines the underlying cause or causes of building failures and makes repair recommendations that not only account for the owner’s long-term goals and constraints, but that also take into account the repair’s effect on the building’s current occupants, the constructability of the repairs, and the availability and compatibility of repair materials.

With respect to new construction, Mr. Baker has partnered with major developers, contractors and architects, reviewing drawings and developing design standards to mitigate the risk of technical failures in both commercial and residential buildings in all climate zones.  Mr. Baker has made valuable contributions to the advancement of energy efficient design in his role as project manager for the Department of Energy’s Building America program.  Mr. Baker has also performed both laboratory and field exposure testing to examine the long-term system deflection resistance capacities of wall assemblies insulated on the exterior.  This research has been used to validate and develop attachment guidelines for various cladding types installed over continuous exterior insulation. Additionally, in collaboration with Catholic Charities Group and Louisiana State University, Mr. Baker developed flood resistant design concepts to assist with their re-building efforts after hurricane Katrina. Mr. Baker’s approach used energy efficiency and durability gains to offset the cost of the additional structural measures required for hurricane and flood resistance.

Mr. Baker holds a Bachelor of Science in Civil Engineering from University of Alberta and is a registered professional engineer in the Province of Alberta, Canada.

Kohta Ueno's picture
Senior Associate, Building Science Corporation

Kohta Ueno’s work at BSC includes forensic field investigations of building failures and consulting work for new and retrofit construction in the design of building enclosure and mechanical systems.  Mr. Ueno also frequently performs computer modeling (using WUFI, THERM, and HEAT3) as well as field testing and verification, HVAC design, and residential energy analysis and simulations.

Mr. Ueno has conducted extensive research and field work on building science topics under the Department of Energy’s Building America program. This researched covered topics as varied as the hygrothermal behavior of basement wall insulation, double stud wall durability, interior insulation retrofits of mass masonry buildings, multifamily ventilation systems, and simplified space conditioning systems. Earlier research work included monitoring of vapor control in above grade walls, self-dehumidifying roof assemblies, drainage and drying of wall cladding materials, and comparative performance of interior foundation insulation systems.

Mr. Ueno is a dynamic speaker and a frequent presenter at academic and industry conferences such as the Northeast Sustainable Energy Association (NESEA) Buildings Conference, the Energy & Environmental Building Alliance’s (EEBA) Excellence in Building Conference, the Passive House Conference, and the Boston Society of Architects’ Architecture Boston Expo.

Mr. Ueno received his undergraduate degree in Material Science at the Massachusetts Institute of Technology and his Master of Applied Science in Civil Engineering from the University of Waterloo.

View Kohta Ueno's M.A.Sc. Thesis

View Kohta Ueno's Fine Home Building Interview

Ashley Owens's picture
Graphics, Newsletter, and Website Manager, Building Science Corporation

Ashley Owens is a Registered Architect with over 12 years of experience in the building industry. She has been involved in the design and renovation of projects in the residential, commercial, and institutional sectors. She holds a Bachelor of Architecture degree from the Boston Architectural College and believes strongly in community involvement by the design profession.