 As principal of Louis Sauer Associates, Architects, Philadelphia, his work in the period 1961–79 focused on over 90 residential and urban design commissions in differing contexts, from central city urban infill to suburban and rural areas, and new town developments at Reston (Virginia), Columbia (Maryland) and Montreal (Quebec).His innovations in low-rise high-density housing breathed new life into the previously maligned 'row-housing' form.Sauer's designs for the David Buten House Philadelphia in particular, and Pastorius Mews, were early templates for the system he developed.