Living alone
The epidemiologist Amélie Keller pooled four cohorts from Denmark, France and the United Kingdom, 69,136 people surveyed in spring 2020, and put housing conditions against loneliness, anxiety and life satisfaction. Living alone carried an odds ratio of 3.08 for loneliness, at a confidence interval running from 1.87 to 5.07, and 1.27 for lower life satisfaction. Lacking outdoor space and living in a crowded household pointed the same way without reaching the same certainty.
The epidemiologist Jonathan Groot found the same shape in the young. Among 7,445 Danes of median age 20, surveyed at 18 and again three weeks into the first lockdown, living alone rather than with parents more than doubled the odds of loneliness starting, at 2.12. Having no access to outdoor space carried 1.72 for the onset of low mental wellbeing, and a denser household 1.26.
The sociologist Haena Lee used eight years of the Health and Retirement Study, 1,893 older Americans, with trained observers recording the state of the neighbourhood and the home rather than asking residents about it. The odds of falling were 2.65 where stairways were poorly maintained and 2.10 where there was green space, both at p below 0.05. Both were significant only for the people living alone. Among people living with others, not one environmental risk factor reached significance across the eight years.
The psychiatrist Stéphanie Bourion-Bédès surveyed 471 French children from 341 households during confinement. Living in an apartment gave an odds ratio of 1.8 for poor quality of life on the social support and peers dimension, never leaving home 2.6 and indoor noise 2.3. Conflict with the other occupants of the dwelling reached 2.9 for psychological wellbeing, 2.4 for the school environment and 2.2 for parent relations and autonomy.
2 studies describe the supply rather than the people. The geographer Phil Hubbard went through English planning appeals since the national space standard was introduced in 2015. Appeals by developers usually fail once a home is 10% or more below it, but where a council has not adopted the standard, inspectors have set it aside: one 2019 decision approved an 18-square-metre flat, more than 50% below the minimum for one person. The housing researcher Fanny Blanc and Scanlon report the counter-movement. Londoners aged 16 to 34 living alone fell 10% between 2001 and 2011, from 225,978 to 202,525, while those sharing with other adults rose 28% to 166,588.
The lighting researcher Kianoush Vali measured what the dwelling then supplies. 16 older adults living alone wore spectral sensors through a winter and a summer. Median daytime melanopic illuminance was 31.2 lux, far below what circadian regulation needs, and the window-to-wall ratio of the building explained only a modest part of it.
Keller’s 69,136 and Groot’s 7,445 are the large samples, both surveyed during lockdown. Lee followed 1,893 people for eight years, the only long run here. Vali worked with 16 people, and Hubbard and Blanc are analyses of decisions and statistics rather than of people.

The sources
- 69,136individuals pooled across four cohorts in Denmark, France and the UK, where people living alone reported loneliness at 3.08 times the odds of people living with others (95% CI 1.87 to 5.07). The same comparison gave 1.27 for life satisfaction.Keller et al., Scientific Reports, 2022 · 10.1038/s41598-022-09316-4
- 1,893older Americans followed for eight years, where poorly maintained stairways raised the odds of falling 2.65 times and the presence of green space raised them 2.10 times. Both held only for those living alone; for people living with others, no environmental risk factor was significant.Haena Lee and Janis Lim, Innovation in Aging, 2023 · 10.1093/geroni/igad055
- 7,445Danes of median age 20, where those living alone rather than with parents reached 2.12 times the odds of becoming lonely (95% CI 1.59 to 2.82). No access to outdoor space gave 1.72 for low mental wellbeing and a denser household 1.26.Groot et al., Scientific Reports, 2022 · 10.1038/s41598-022-04909-5
- 471French children from 341 households, where those living in an apartment reached 1.8 times the odds of scoring poorly on the social support and peers dimension of quality of life, with never leaving home at 2.6 and indoor noise at 2.3.Bourion-Bédès et al., BMC Public Health, 2022 · 10.1186/s12889-022-12941-3
- 18 m²was the floor area of a flat approved on appeal in England in 2019, more than 50% below the national space standard for one person. Appeals usually fail at 10% below, but where a council has not adopted the standard the inspectorate can set it aside.Phil Hubbard, Journal of Property Planning and Environmental Law, 2023 · 10.1108/jppel-01-2023-0002
- 31.2 luxmedian daytime melanopic illuminance measured on 16 older adults living alone across winter and summer, well below the recommended level. Their nights were not polluted with light, and the window-to-wall ratio of the building explained only a little of it.Kianoush Vali et al., CIE Proceedings, 2025 · 10.25039/x051.2025/v57y54
- −10%in Londoners aged 16 to 34 living alone between 2001 and 2011, from 225,978 to 202,525, while those sharing with other adults rose 28% to 166,588.Blanc and Scanlon, Buildings and Cities, 2022 · 10.5334/bc.182
Findings compiled by The Built Review