Will your green roof bring you money?

Things are not going well in our Flemish cities. The air is so dirty and unhealthy that we urgently need to do something about it. Every leaf or blade of green helps. And for those who do not have a garden to plant a tree, a green roof may be a smart alternative. Not yet convinced about moss or grass on your roof? Too expensive? According to Dr. Kathleen Smolders (UHasselt) it is a smart investment.