[2] She graduated in 1923 with a degree in architecture and was the first woman to be awarded the school medal for academic excellence[1] by the American Institute of Architects (AIA).

These medals were granted each year to an outstanding student in each of the architectural programs recognized by the AIA.

They bought a 1789 abandoned farm in Hadlyme, New London County, Connecticut, and set about renovating it.

In 1933, they opened a joint architectural practice in their home and began working mostly on residences, completing some 70 drawings before 1940.

Before her retirement in 1977, Pfeiffer completed over 170 residential designs, mostly in Connecticut, but she did two Arizona ranches, as well as a bank and a church.