The Housing Act 2004 introduced a new way in which local authorities ("councils") assess housing conditions in England and Wales. It uses a risk assessment approach called the Housing Health and Safety Rating System (HHSRS); the aim is to provide a system (not a standard) to enable risks from hazards to health and safety in dwellings to be removed or minimised.
It replaces the fitness standard which dated back to 1919. The fitness standard did not deal with many of the hazards that affected health and safety; in addition it was only a pass/fail standard with assessments giving no indication as to how unfit (or how fit) a property was. Assessments made under the fitness standard were 'property based' and did not directly consider the effect of the particular defect or omission, on the occupant or visitor. The HHSRS on the other hand addresses all the key issues that affect health and safety, it provides an analysis of just how hazardous a property is and includes evidence and statistical information to assist inspectors in making their judgements.
Each year on average, housing conditions are implicated in up to 50,000 deaths and around 0.5 million illnesses requiring medical attention. These statistics and many others form part of the evidence base of the system and are drawn from extensive research in the UK (in this case the Home Accident Surveillance System). The fitness standard did not address many of the conditions that caused these deaths and injuries.