Dr. Badois is in a suburb of Paris called Soisy Sous Montmorency. His office is across the street from Hotel de Ville de Soisy (city hall) Dr. Badois sent excellent directions by eMail explaining how to get to his office:
From Charles de Gaulle Airport, about 40 minutes by taxi. From Paris, take a taxi or the train ( about 35 minutes) at "Gare du Nord" Station, direction Pontoise (upstairs from metro), stop at "Enghien Les Bains" Station. Then you can choose beetween taking the bus (N°11) to "Hôtel de Ville de Soisy" (Town Hall) or a taxi to my office, which is close to the post office of Soisy and adjacent to a Pharmacy (green cross) and a medical laboratory.
We were driving a rental car. We departed Chartres the morning of the day of my appointment. We arrived at Soisy by noon and took lunch at a nice Thai restaurant. We blundered about some one way streets a bit, but eventually located the Hotel de Ville. The office itself is upstairs in a building adjacent to the pharmacy. We buzzed Dr. Badois at 2:20 PM; he opened the door and we went up to his office.
By the time of my second appointment, we had returned the rental car and were staying at a hotel in Paris. We used the RCRF rail system to get from the Gare Nord to Enghien Les Bains. The directions said to take bus #11 to Soisy. However, we were early, the weather was great, and there was no bus standing there, so we decided to walk. We knew it was about a mile or so from our driving experience at the first appointment. We set off confidently, and only had to stop and ask directions twice.