He built in a variety of styles: "semi-Dutch, semi-Flamboyant a la George & Peto" at West Hartlepool, half-timbered on houses and schools (for example Bryerswood and Peel school. For churches he favoured late Gothic styles, often with a French influence. Pevsner (2005) likens his work to that of R B Preston, referring to his "effective but reserved Arts and Crafts detailing". See Architectural style.
Frank Freeman, like his father, designed many types of building and won commissions through competitions. There are no buildings prior to 1904 attributed to Frank Freeman so it is difficult to know what he worked on when his father was alive. There is also some confusion about who designed some of the buildings in the years immediately after Knill Freeman’s death. This is further confused because Frank worked on a number of buildings started by his father, (for instance St Catherine, Horwich and St Aidan, Bamber Bridge), signed his name “Richard Freeman” and designed in a similar style. He was particularly known for designing war memorials.