The current demographic and socioeconomic scene causes an increase of people living in substandard housing(1,2) , affecting both public and individual health(1,3–7). The aim of this study is to determine the health-related Quality of life (HRQoL) quality of life in people who live in substandard housing. To that, the SF-12v2 questionnaire was used on 46 adults living in Gran Canaria´s (Spain) settlements between February and April 2022. The results were low in all the domains and summative components of the questionnaire, apart from the vitality domain. The mean physical component summary (PCS) was 48.9 (±10.8) and the mental component summary (MCS) was 43.75 (±11.16), both values below the standard population norm (50±10). The best valued dimension was Vitality (M=54.52) and the worst was Body Pain (38.16). The country of birth, age, the characteristics of the home and the environment were determinant for the scores. The present study reflects that living in substandard housing influences HRQoL, we have brought the participants closer to the health services and a map of the housing situation in the south of Gran Canaria has been generated, as well as a methodology that can be exported to other territories.

The identification of potential participants was carried out by snowball sampling. Known individuals were identified with 4 methods: • Canary Islands Health Service: An information record sheet (Annex 1) was distributed among the health workers of the ZBS of Maspalomas and Vecindario to introduce the study and collect information about participants, settlements or resources. Likewise, collaboration was requested from the Mental Health Units of Barrio Atlántico and Vecindario, as well as the Assertive Community Treatment Team (ETAC). • Public agencies: Telephone contact with Social Services of the municipalities that host the basic health areas that are studied. In addition, Social Inclusion programs and Civil Protection were contacted. • Privately based entities: Personal contact with Cáritas Diocesana de Canarias and Spanish Red Cross. • Informal methods: Fieldwork visiting the settlements, press search and contact with neighborhood associations. Through this process, a database was generated to coordinate the visits which would be arranged with each of the participants through contact by phone, to first inform of the research and to choose a date for the visit either in the Reference Health Center or in their home. At the time of the personal contact, we carried a presentation of the researchers, reference institution, project and then we offered the informed consent and authorization for data management (Annex 3). Data collection was carried out in Gran Canaria between January and March 2022. For the measurement of self-perceived quality of life, this study used the SF-12 health questionnaire in its version 2 (Annex 1). Due to its brevity, ease of use[17] and use in other reference studies[3]. The housing characteristics analysis tool (Annex 2) was elaborated adding interesting elements for the study to a social assessment questionnaire[18,19]. This Household Questionnaire consists of 21 items that encompass 6 dimensions of housing: Property, Inhabitants, Housing Characteristics, Supplies, Intrinsic Problems and Neighborhood. Both questionnaires share a section that reflects the date of birth, nationality and gender.