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LDR has a team of professionals, with years of combined experience in the building science and construction industry, who are led by the following Professional Engineers.


Sean Liaw, B.Eng., M.Eng., BEP, FEC, P.Eng.

Sean is a Senior Building Science Consultant and a Principal of LDR.  He has Master of Engineering Degree in Civil Engineering (1992), for which he conducted research on the cavity pressurization of various rain screen wall designs.  Since then, he has worked for 25 years on projects in British Columbia, Washington State, Alberta, and Ontario.   For most of those years, he has been based in the Lower Mainland.  He is a member of Engineers and Geoscientists BC, has been recognized as a Building Envelope Professional (BEP) since April 11, 2000, and is a member of two Committees at Engineers and Geoscientists BC (Building Enclosure and Consulting Practice).  He founded and served as manager of the exp (formerly known as Trow Associates Inc.) Building Science Division in BC, is a former principal at RDH Building Engineering Ltd., and is one of the founders of LDR Engineering Group.


Sean has been involved in assessments of over 150 building envelope failures.  He has acted as the P.Eng. on over 50 building envelope rehabilitations, performing field reviews and construction contract administration.  In fact, he was involved in some of the earliest exterior wall re-cladding rehabilitations with rainscreen in the Lower Mainland (circa mid-1990s).


In addition to assessment and rehabilitation of existing building envelopes, Sean has acted as a building envelope consultant on numerous (over 50) new construction projects, ranging from single family dwellings to high rises of over 40 stories.  Services provided typically included the review of architectural drawings and specifications for building envelope issues, the review of the building envelope during construction, and the review of building envelope related shop drawings. 


Samer (Sam) Daibess, B.A.SC., P.Eng.

Sam is a Senior Building Science Consultant and a Principal of LDR.  Sam is a professional engineer with over 19 years of experience in engineering consulting, with the majority of his experience in the building science field. Sam has provided services on hundreds of building science projects throughout his career as a building science consultant. Prior to LDR, he founded JSD Engineering, served as senior project engineer and manager of exp (formerly known as Trow Associates Inc.), and served as a project engineer and manager of Morrison Hershfield, and he is a co-founder of LDR Engineering Group. He is a member of Engineers and Geoscientists of BC, and has been on the British Columbia Building Envelope Council (BCBEC) Board of Directors since 2008. Among the many roles that Sam held at BCBEC, he was recently the President of BCBEC. He is currently the Past President of BCBEC.


Sam specializes in the investigation of building enclosure failures, and building enclosure rehabilitation design and field review. Sam has acted as the engineer of record and project manager on tens of targeted and full building enclosure rehabilitation projects on multi-residential low-rise and high-rise buildings. Sam also specializes in new construction design and field reviews, project management and contract administration, re-roofing and waterproofing, building condition surveys, project supervision, performance verification, concrete parking structures condition assessments, and concrete parking structures restoration design and field reviews.



Christopher is a Senior Building Science Consultant.  He has been involved in the building science industry for over 15 years.  During that time he earned a Master of Applied Science degree in Civil Engineering, specializing in building science engineering, from the University of Waterloo.  Since then, he has worked for 12 years in British Columbia, based in the Lower Mainland.  He is a member of the Association of Professional Engineers and Geoscientists of BC (APEGBC), a Certified Passive House Designer, instructed the Building Science 2 (BLDG4100) class at British Columbia Institute of Technology (BCIT), and is currently instructing Building Envelope Performance (BLDC3050) and Basic Project Management Skills (BLDT2021).


Christopher’s work experience has included a wide range projects including managing or contributing to a variety of projects including new construction, rehabilitation (both targeted and complete rehabilitation), warranty reviews, depreciation reports, insurance claims, building enclosure condition assessments, forensic investigation, research, and both field and laboratory testing.  Through this experience he has extensive experience with various building enclosure elements such as roofing, waterproofing, cladding, and windows.  He has worked on both residential and commercial buildings, and on low rise combustible (wood frame) to high rise non-combustible (concrete frame) buildings.


Resumes with more detailed descriptions of our team members’ experience are available upon request.

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