@ElizaBennett - Something else to keep in mind with green building materials is what your floor covering will be. Carpet is made of synthetic materials these days and it also is known for outgassing.
So there are a few different options. You can get carpet made of wool or other natural fibers that hasn't been treated with toxic chemicals, or you can look into alternate flooring materials, like stone or (sustainable) wood. An advantage of hard flooring is that it is easier to keep really clean. You don't have to have it shampooed with harsh chemicals every year and it doesn't hold in allergens, indoor air pollution, etc.