What are the signature architectural details that make a Wilbraham building a Wilbraham building?

First we must agree to the overall elegance of design, the balance of windows to brick, the proportions of entrances, chimneys and more.

Most famously perhaps are Wilbraham’s sash windows, designs which some claim are original to her. Certainly she took the standard of sash window designs with frames and casements taken to a new level and included them in elegant and balanced proportions with high quality glass and frames.