Green roofs and walls ENvironmental Economic and SocIal Savings:

Modelling uncertainty and investors / users preferences in all-inclusive

cost-benefit analysis of green roofs and walls

Nature-based solutions will play an important role in tackling urban challenges in a multifunctional way. Modern green roofs and walls are one of the most promising alternatives as they can green the grey infrastructure and value it in the long run (e.g., water management, biodiversity, air quality, aesthetics and well-being). Yet, green roofs and walls have been generally confined to specific cities or countries. An extensive use worldwide will happen when their economic merit is generally known and accepted.


Since green roofs and walls imply additional costs when compared to traditional solutions, this implies reliable life-cycle cost analyses. Yet,  current approaches do not address all social, environmental and economic aspects nor the complex relationship between them and so their real value is still not clear.




Our purpose  is to enhance existing cost-benefit analysis of green roofs and walls by developing major improvements. To this aim, the main strategy of the project is to include all environmental, economic and social impacts of green roofs/walls and convert them into monetary units to allow weighting different types of benefits and compare alternative scenarios. The model will also comprise an uncertainty model to cope with inaccurate forecasting and climate change. Finally, it will incorporate users/investors preferences through a multi-criteria model.


This all-inclusive model is a step foward and is crucial for a wide spreading of green roofs/walls in buildings and cities. It will improve decision-making process of using nature-based solutions as mechanism towards a more sustainable management of existing resources in the built environment.

  1. Survey of cost-benefit analysis of green roofs/walls

  2. Survey of green roofs/walls projects

  3. Long-term costs/benefits modelling

  4. Translation of benefits into economic gains

Task 1

  1. Establishing a methodological approach to perform cost-benefit analysis

  2. Modelling life-cycle costs         and benefits

  3. Modelling uncertainty in the evaluation

  4. Development of multicriteria model

  5. Development of the integrated model

Task 2

  1. Cost-benefit analysis of greening existing roofspaces in a city

  2. Cost-benefit analysis of greening transport infrastructures

  3. Cost-benefit analysis of greening primary schools

  4. Cost-benefit analysis of greening tourist accommodations

Task 3

Task 4

  1. Workshops

  2. Publications in international journals and conferences

  3. Web page

  4. Guideline towards evaluating green roofs/walls environmental economic and social savings

  5. user-friendly mobile app for quick assessment of the viability of green roofs/walls

Click to see when we are planning to do it !