Defective Premises Act 1972. This Act imposes a duty on those who do work on a dwelling to see that the work is done in a workmanlike or professional manner with proper materials so that the dwelling will be fit for habitation when completed. The Building Safety Act 2022 significantly amended this Act, extending the limitation period for claims from 6 to 30 years retrospectively and 15 years prospectively. This has made it a powerful legal tool for homeowners to seek redress against developers for historical defects, including fire safety defects that render a dwelling unfit for habitation. This page provides a structured summary, key provisions, and practical guidance on the application of Defective Premises Act 1972 to UK fire safety engineering, building design, and Building Safety Act compliance.