Caring for a Garden in an Office Building

We live in a condo and our unit faces an office building. On the second floor there is an outdoor patio - where I have occasionally seen a person sit at the table - and a surrounding garden space that has a few trees planted in it that match the surrounding elements. Yesterday many bags of dirt suddenly appeared. Shortly thereafter a large crew of about ten people arrived and started working on planting additional shrubs and plants and flowers. It took most of the day. Because it is an office building I’m not sure how easy it was to get the tools, equipment and plants up there? And I’m not sure there is even a water spout to attach a hose. Between the office building and our condo we have the same landscaping crew attending to the gardening needs. But I have never seen anyone doing anything on the second floor area. It’s in a strange place. In the end the garden looked nice enough. I guess we will see over time how long it will last. We used to have gardens in our Midwest home and our little patio on Capitol Hill. Now we just have a few window boxes with coco liners that I haven’t even planted this summer. It’s really hard to keep the flowers going with a western hot exposure. My husband has a miniature rose plant that he attends to. I hope it all works out well across the street. It was at least entertaining to watch the crew put it all together.