First Derivative Architectural Services provides architectural services to individual homeowners, builders, developers, designers, engineers, and other industry professionals.

FDAS opened its doors in 1998 in DeKalb, Illinois. In 2000, we moved our main office to Glen Ellyn, Illinois. Our work can be seen throughout Northern Illinois from Barrington to Naperville, and from Oak Park to Sterling, as well as Lakeside Michigan, Stilwell, Kansas, and Alberta Canada.

At FDAS we have tackled residential projects of all sizes and scopes ranging from small remodels with construction costs as low as $3000 up to new $1,500,000 homes.

Our architect, Heidi Lendi, has been a licensed architect with the state of Illinois since 1997 and with the state of Michigan since 2001. She has been NCARB (National Council of Architect Registration Boards) certified since 1998. NCARB certification requires a rigorous internship program and makes licensing in other states and countries easier. She has been a member of the AIA (American Institute of Architects) since 1998. She graduated with honors from Illinois Institute of Technology in Chicago with degrees in Architecture and Mathematics.

Heidi Lendi started FDAS after extensive experience working with a residential builder where she ran multiple subdivisions of semi-custom homes from $200,000 to $600,000. She has also worked on numerous retail stores, healthcare facilities, and educational institutions all over the country.