Dwellings failing the minimum standard are those posing a Category 1 hazard under the Housing Health and Safety Rating System (HHSRS). From 2008 the survey is able to estimate the presence of 26 of the 29 HHSRS hazards. However to maintain consistency and avoid a break in the time series from 2006, Decent Homes estimates continue to be based on 15 hazards for the 'minimum standard' criterion. Estimates for the HHSRS tables (DA4101-3) are based on the 26 hazards covered by the survey.

The Tolerable Standard is a minimum standard for habitability introduced in the 1969 Housing (Scotland) Act, and updated by the 1987, 2001 and 2006 Acts. A dwelling meets the tolerable standard if it:• is structurally stable;• is substantially free from rising or penetrating damp;• has satisfactory provision for lighting, ventilation and heating;• has an adequate piped supply of wholesome water available within the house;• has a sink provided with a satisfactory supply of both hot and cold water within the house;• has a water closet or waterless closet available for the exclusive use of the occupants of the house and suitably located within the house;• has a fixed bath or shower and a wash-hand basin, each provided with a satisfactory supply of both hot and cold water and suitably located within the house;• has an effective system for the drainage and disposal of foul and surface water;• has satisfactory facilities for the cooking of food within the house;• has satisfactory access to all external doors and outbuildings;• has electrical installations that are adequate and safe to use. The "electrical installation" is the electrical wiring and associated components and fittings, but excludes equipment and appliances;• has satisfactory thermal insulation. The Scottish Housing Quality Standard (SHQS) was announced by the Minister for Communities in February 2004. A target was agreed that all social landlords must ensure that all their dwellings pass the SHQS by 2015. Private owners and private landlords are currently under no obligation to bring their properties up to a standard which meets the SHQS. However SHCS collects the same data for all dwellings to allow comparison across the housing stock. The SHQS is an aggregation of the results from 55 different elements grouped into 5 higher-level criteria, which in turn provide a single pass/fail classification for all dwellings. The 5 higher-level criteria specify that the dwelling must be: • above the statutory tolerable standard;• free from serious disrepair; • energy efficient; • with modern facilities and services; • healthy, safe and secure.

Overall proxy measure of WHQS - The previous housing conditions survey in Wales, the Living in Wales Property Survey 2008, assessed the social housing stock in Wales against elements of the WHQS; Living in Wales 2008: Welsh Housing Quality Standard. In that assessment, a dwelling was considered to have met the WHQS if it passed all 13 primary elements and at least 9 (or 75%) of the 13 secondary elements, as measured by the 2008 Survey. This was a proxy measure since the Survey only assessed a subset of elements in the standard. The same methodology has been followed to calculate an overall proxy measure of WHQS using the data from the 2017-18 Survey. The overall modified proxy measure includes the questions 'Is there a shower as welll as a bath?' and 'Are there adequate facilities for washing, drying and aring clothes?'This report uses only a subset of the elements required to fully assess the WHQS, therefore care should be taken when using the figures provided. Official statistics on WHQS for social landlord housing are produced by the Welsh Government based on returns from social landlords. Users wanting to look at trends in meeting the quality standard for social housing over time should use the Official Statistics, those wanting to compare across tenures should use this report (noting that only a subset of elements have been measured). The two data sources are not directly comparable.

The term "acceptable standard" includes dwellings deemed to be "satisfactory" or "acceptable" in standard.