Think of two scenarios.
In the first, you’re back in high school, and your family just moved to a new city where you don’t know anyone. It’s your first day at school. How do you feel? How do you behave? Who do you talk to?
In the second scenario, you’re moving to a different high school where you know a few people but not that many? It’s your first day at school. How do you feel? How do you behave? Who do you talk to?
While the building may be different, the real environment that makes you feel welcome or not is the people you hang out with day after day, your friends and fellow students, the teachers and, to a lesser extent, assistant principals, counselors and the principal.
It’s the same thing when you go to work. It’s not the building or even the work that makes you feel welcome. It’s the people. If it’s your first day on the new job, you’re on shaky ground, not quite knowing how to behave, what the rules are, who’s really in charge, and where the best place to eat at the cafeteria is (just like in high school). It takes a while to learn all of that.
While you a contribute a certain element to the atmosphere, there is already a substantial atmosphere in place that you will mostly conform to. It takes a lot to change the atmosphere.
Contrast that with a start-up or newly formed company. The first couple of generations of workers at the new company get to create the new environment. Then, it tends to take on a life of its own and live on for decades. New CEOs, directors, supervisors, managers and staff come and go, but the culture lives on. Sure, it’s modified along the way with each new generation, but the basic structure of the culture remains.
After that, new leadership (not necessarily management) can change the environment with some dedicated work. It’s long term and needs to be focused. Like most other things, it starts from the top leadership levels.