Maybe I'm inferring a subtext here, but I think you're asking about how environment facilitates this. It's definitely true that homes with lawns make this easier than say apartments. Part of this is that you're more likely to spend time outside owning a home as you need to simply work on the yard. But the main causal factor is likely just seeing people frequently. Like one reason it was easier to make friends in school was simply because you sat next to people and see them every day. That builds relationships. The same thing happens with work, you spend 8+ hrs a day there with the same people. Some businesses try to curb this, which is curbing natural human interactions and others encourage it too much which feels forced. Weirdly the most significant factor to building relationships is spending time with people. More so than things like religion (correlates because time in church), politics, or other things that we think are major barriers and encourages us to turn to bubbles.