Programmes in nature lowered anxiety, mostly in trials where the control group did nothing
A new head office in Thailand raised its staff's satisfaction with air, views and noise, and it also lengthened the commute for almost two thirds of them, which cost part of what the building did for their sleep. In Beijing, crowded homes and too little green space went with depression, and each went with it most strongly in a different group of residents. A pooled analysis from the same months put the drop in anxiety from programmes in nature at 0.83 standard deviations, measured mostly against doing nothing.
Written by
Christian Huser
neuecon partners
I think a finding should become a requirement for a building only when a study gives the size of its effect and the people it affects.
Four studies linked nature or better conditions with better mental health
In June 2026, I chose four studies for a trend report for The Built Review: a pooled analysis of systematic reviews of programmes in nature, a review of studies of sound, a survey of the staff of one firm before and after a move to a new office, and a survey of residents of Beijing about their homes and the green space near them. Each linked nature or better conditions with better mental health.
A large effect, measured against doing nothing
Programmes in nature lowered anxiety by 0.83 standard deviations. The psychologist Esmaeel Saeedy Robat and colleagues reached that figure in 2026 by merging the results of 30 systematic reviews, taken from a pool of 116 reviews that covered roughly 3,870 primary studies and an estimated ten million people. A standard deviation is the usual spread of the scores within a group, and by the usual convention in psychology a gap of 0.8 or more counts as large. Depressive symptoms fell by 0.72 standard deviations, and positive mood rose.
In most of the trials behind these figures, the control group did no activity. Saeedy Robat and colleagues write that these passive control groups limit what their figures show about nature compared with another treatment. The measured effect is almost certainly larger than the real one, and its true size will stay unknown until trials test nature against an active alternative.
Weak evidence on sound
In 2026, the architecture researcher Jingyi Mu and colleagues reviewed 180 studies of older adults, children, people with hearing loss and hospital patients. Across these groups, poor acoustics generally went with poorer health, weaker cognitive performance and worse mood. The authors rated their own certainty in most of these results as low or very low.
A longer commute offset part of what a new office gave
What a new office gave its staff depended partly on how they got to it. In a study published in 2026, the sociologist Dorota Weziak-Bialowolska and colleagues surveyed the staff of one firm in Thailand three times: in eight dispersed offices, while they worked from home during COVID-19, and in a single new head office designed for daylight, views and clean air.
After the move, the staff were more satisfied with every domain of the indoor environment, most of all with air, views and noise, and those who were more satisfied reported better wellbeing. The move also lengthened the commute for almost two thirds of the staff, and the longer commute offset part of the gain in sleep and wellbeing.
Crowding and green space went with depression in different residents of Beijing
The researcher Xuelu Wang and colleagues surveyed residents of Beijing and published the results in 2026. Each person answered once, so the links in their figures could run in either direction.
Crowded homes and too little green space nearby both went with a higher risk of depression. The link with crowding was strongest among local residents, and the link with green space among migrants. Both links also varied by gender and by family structure. The authors conclude that planning for mental health should cover indoor and outdoor conditions and aim at the groups exposed.
A requirement needs a size and a group of people
A garden takes space from another use. The 0.83 standard deviations were measured mostly against doing nothing, so they say little about what a garden adds compared with that other use. I think a finding should become a requirement for a building only when a study gives the size of its effect and the people it affects. A rule for every occupant would treat a local resident in a crowded home and a migrant with too little green space nearby as one case, although the Beijing survey found that different conditions went with depression in the two groups.
Sources
- Saeedy Robat and colleagues 2026, "A systematic overview and second-order meta-analysis of nature-based interventions for stress, anxiety and depression", Nature Human Behaviour. https://doi.org/10.1038/s41562-026-02433-4
- Mu, Qin and Wang 2026, "Effects of Acoustic Environments on Well-Being in Sensory-Vulnerable Populations: A Systematic Review", Journal of Multidisciplinary Healthcare. https://doi.org/10.2147/jmdh.s589528
- Weziak-Bialowolska, Powers Tomasso and Spengler 2026, "Workplace design for human flourishing: Evidence from a purpose-built, health-promoting corporate headquarters in Thailand", Journal of Building Engineering. https://doi.org/10.1016/j.jobe.2026.116546
- Wang, Liu and Wang 2026, "Enclosed by Walls, Embraced by Trees: Effects of Indoor Residential Crowding and Outdoor Green Space on Mental Health", Journal of Planning Education and Research. https://doi.org/10.1177/0739456x261432155
- The Built Review, "Nature helps mental health. How much, and for whom, is the harder part.", trend report Q2 2026, June 2026. https://thebuiltreview.com/trend/q2-2026