Keeping plants alive requires labour and water. Labour is expensive. Water needs to be kept carefully contained, unless you want it to destroy your building.
It's easy if you select the right houseplants. Most of my houseplants don't require a lot of water. I have a sunroom with cactuses that I give occasional drinks in the winter, and then every 2-3 weeks in the summer I drag the hose in and soak the pot. Doesn't take much time at all.
IMO, they will probably choose the plants carefully and set up an automatic watering system.
IMO, they will probably choose the plants carefully and set up an automatic watering system.