Okay kiddo, so you know how when we build houses and buildings, we often use a lot of things that aren't very good for the environment? Like some materials might create a lot of pollution or use up a lot of energy?
Well, some people want to make sure that when we build things, we try to be more friendly to the environment. So they made a set of rules called the National Green Building Standard.
These rules tell builders how to make houses and buildings that use less energy, create less pollution, and are overall better for the environment. They might even use things like special light bulbs, insulation, or toilets that don't use as much water.
So when someone builds a house or building and follows these rules, they can say it meets the National Green Building Standard. This is kind of like getting a gold star for being good to the environment!