The objective of this study was to determine the extent to which residential developments in Kisii Town complied with Building Coverage Ratio (BCR) and Floor Area Ratio (FAR) physical planning standards. To attain this, analysis was undertaken using paired sample t-test, one sample t-test and correlational analysis. Results revealed that on average, though the recommended mean standard for BCR was 69.10%, the observed mean compliance was 75.55%, depicting noncompliance. At the same time, the observed mean compliance for FAR was 189.81 against the mean recommended standard of 311.51, suggesting overall compliance. Nevertheless, when developments were individually analysed, it was found out that 42%, 18.6%, 20%, 16.1%, 9.8%, 15% and 43% in Nyanchwa, Jogoo, Nyamataro, Egesa, Daraja Mbili, Mwembe and Nyamage did not respectively comply with the recommended FAR. The null hypothesis of no statistically significant difference between the recommended physical planning standards and their observed extent of compliance was as well tested. Results found a statistically significant difference (M=199.62, SD = 130.26) and (M = 136.84, SD = 60.21), that was significant, t (12) = 3.001, p = .011, an indication of inadequate development control. The study concluded that the County Government of Kisii had failed to effectively regulate residential building developments in the study area, thus negating the objective of sustainable urban development. A policy recommendation was made for adoption of a strict enforcement and monitoring regime that ensures overall compliance with recommended FAR and BCR in Kisii Town.