An assessment of materials and process details as an indicator of environmental impact of green roof market solutions
Student name: Ms Shikha Ranjha
Guide: Prof R.L.Sawhney
Year of completion: 2012
Host Organisation: Institut Umwelt und Naturiliche Ressourcen Zhaw, Wadenswil, Switzerland
Supervisor (Host Organisation): Dr Stephan Brenneisen
Abstract: Purpose: A market service such as a Green roof installation, involves manufacturing and disposal of
a lot of materials that make up each layer of the green roof. These materials affect the environment
most during the first and disposal stages of their life cycle. The purpose of this study is to compare
these materials and process involved in their manufacturing for Green Roof market solutions
provided by at least three different companies.
Methodology/Approach: The analysis of environmental impact of materials involved in each layer is
done quantitatively. It is mainly based on Embodied energy, Ecological scarcity, and Greenhouse gas
emission calculations per unit roof area. These calculations have been done for the
Extraction/Fabrication, and Demolition/Disposal stages of their life cycle.
Findings: The green roof systems that contain more amounts of technical substrate for vegetation
have a high environmental impact. The manufacturers in making their system light weight use energy
intensive mineral aggregates or expanded clay. This increases the amount of embodied energy in the
product and also put pressure on natural resources for their extraction. The impact is also higher for
intensive roofs which have higher thickness of growth medium in comparison to extensive roofs.
Practical implications: Product Designers and Green Roof landscape artists can use the
methodology and findings to decide on which materials to avoid or use in designing a more
sustainable product. The results of the study can also be used by customers in making a decision
while choosing the type of green roof they want.
Originality/Value: The study points out the significance of use of certain kind of materials in market
products and the impact they have on the environment during their life cycle.
Keywords: Green roofs, Materials management, Embodied energy, Ecological scarcity,
Environmental impact.
