This evidence sheet is published by The Built Review.
Americans spend 87% of their time inside buildings and a further 6% inside vehicles. The environmental health scientist Neil Klepeis established that in 2001, using 9,386 24-hour diaries collected by telephone across the United States over two years, and they held steady across regions and across a decade. Everything below happens inside that 87%.
The sport scientist Birgit Wallmann-Sperlich followed twelve people out of a conventional office into one designed to be active and biophilic at once, surveying them a month before the move and three and seven months after. Standing time during office hours rose by about 40 minutes a day, at p below 0.01. Nothing else moved. Not work engagement, not satisfaction with the office, not performance.
The biologist Daniel Brown ran the most rigorous test in this group and most of it came out null. Ninety-four office workers at an international company were randomised in 2014 to a control group, to a lunchtime walk through trees and maintained grass, or to a lunchtime walk through housing estates and industrial areas, twice a week for eight weeks, and 73 finished. Resting autonomic function did not differ between the groups. Self-reported mental health rose by 2.7 SF-8 points in the nature group alone, with a confidence interval running from 0.0 to 5.4. Adherence was 42 and 43%, and Brown concludes that two suggested active lunchtimes a week with little support is not enough to change anything.
The psychologist Patrik Andreasson asked eight office workers in 2025 to do at least 30 minutes of their work outdoors every day for a week. They managed 322 minutes across the week, roughly 64 minutes a day, mostly in urban nature. Self-rated stress was 15% below the previous week. It was significant on a paired t-test and not on a Wilcoxon test, and Andreasson reports both rather than choosing.
The psychologist Margherita Pasini followed 57 employees of an Italian office through a move they helped design, and 45 to 47 of them answered the survey after it. A view connected with nature correlated 0.54 with job satisfaction. Areas set aside for destressing correlated 0.58 and natural light 0.50. The view ranked second of the three.
The information systems researcher Tobias Ramm had 15 students from Cologne play a puzzle game indoors and outdoors in 2024. Groups finished in 103.2 seconds outdoors against 122.4 indoors, 15.68% faster. Individuals finished 5.64% faster outdoors, in 100.3 seconds against 106.3.
The samples on this sheet run 8, 12, 15, 57 and 94. Klepeis is the exception at 9,386, and it records where people are rather than what being there does to them.
