I am an architectural historian, former National Park Service historian, architectural photographer, and licensed tour guide who has been giving these D.C. tours for years.
They have been well received by locals and visitors to D.C. who want something other than memorized, superficial spiels on Washington history and buildings.
The tours are given at 10:30am, 1:00 pm, or 3pm. Which tour and at what time depends on demand.
Please feel free to email me at architecturalphoto@mac.com, call me at 301 467 2831, or see my postings on facebook , BillLebovich.com, or twitter.