Some sources:

1. https://www.footprintnetwork.org/our-work/ecological-footprint

2. https://www.footprintcalculator.org

3. https://books.google.co.uk/books?hl=en&lr=&id=WVNEAQAAQBAJ

4. https://www.sciencedirect.com/science/article/pii/S1470160X15005269

5. https://www.sciencedirect.com/science/article/pii/S0921800908003376

for buildings see

https://www.sciencedirect.com/science/article/abs/pii/S0360132316301640

The environmental footprint structure typically includes the following categories:

1. Carbon footprint: This measures the amount of greenhouse gases (primarily carbon dioxide) emitted as a result of an activity or product. Carbon footprint is a commonly used measure of environmental impact, as greenhouse gases contribute to global climate change.

2. Water footprint: This measures the amount of water used and/or polluted as a result of an activity or product. Water footprint is an important measure, as water scarcity is a growing concern in many parts of the world.

3. Land use footprint: This measures the amount of land required to support an activity or product. This includes both the physical space required (e.g. for buildings or infrastructure) and the land used for growing crops or raising livestock.

4. Biodiversity footprint: This measures the impact of an activity or product on biodiversity, including the loss of species and habitats.

5. Ecological footprint: This measures the overall impact of an activity or product on the environment, taking into account all of the above factors as well as other environmental impacts such as waste generation and pollution.