It’s a Tuesday morning in the year 2036. A maintenance worker arrives at your apartment to take a look at that crack in your kitchen wall. She carries no drywall, sealant, or fillers. Instead, she checks to see whether the friendly bacteria in the wall itself have started healing the fissure. Next, she leans out the window to see whether the moss coating in your living wall is still lush and able to filter out pollutants from the city air. Befor…