Office Fitout Design & Construct. Sheldon was founded in Sydney in 1989, by a team determined to take on a fresh approach to the design and construct process. Results driven, in 30 years since inception, we've never stopped looking for more efficient and cost effective ways to do things. Our innovative team now includes divisions from interior design right through to furniture manufacturing, project management and electrical, each working together from start to finish on a project. From the beginning our teams are working together to ensure that all elements of your project have been thought about from all angles.