No, building is not a resource
Human resource
A factory building is a physical resource used for manufacturing goods. It is considered a capital resource as it contributes to the production process and adds value to the final product.
A resource is a material that is useful to humans (such as water,building marerial,fossil fuels,crops...etc)
Wood was the most commonly used natural resource for building. It was readily available, easy to work with, and provided a versatile material for constructing structures. Additionally, it offered natural insulation and was a sustainable resource when harvested responsibly.
That could be related to a number of issues. One could be your wheat production. If your main building is at a certain level, you are not allowed to build unless you have a certain wheat production. Another reason is that you are only allowed to build one building/resource field at a time. Romans are excluded from this rule and may build one building and one resource at the same time.
yes it is, it can be crushed and reprocess into alternative building materials
Cedar timber.
One example of a natural resource found on land is timber, which is harvested from forests and used for building materials, paper products, and fuel.
you research technologies by accessing the academy of your town. Each Technology have building and resource pre requisites.
It increases the supply of electricity from alternative sources
Concrete is a man-made material that is produced by mixing cement with aggregates and water. It is not a natural resource, but rather a construction material that is widely used for building structures.
A green building that is designed and built to be environmentally friendly and resource-efficient throughout the life of the building. When constructing a green building you should look to use all of the latest technologies that are aimed at being environmentally friendly such as solar panels and water efficency products.