Following the life-cycle approaches in building industry what my first post was about as well as my area of interest; this post will be dealing about Green Building Certification Systems (GBCS) and their own individual criteria concerning the life-cycle criteria for each one.
Altohugh the main GBCS are LEED-USA, BREEAM-UK, DGNB-Germany, HQE-France and VERDE-Spain, this post will focus on LEED, BREEAM and DGNB due to their development and extended use even in Spain (LEED, BREEAM) at the expense of its own VERDE certification system.
There is growing demand of these sustainable certifications and therefore of documentation regarding Life Cycle Assessment. LCA is recognized as a strong and unique quantitative tool to assess the environmental impact of building, accepted by internacional ISO standards (ISO 14040). However, it is not yet a consistent requirement of Green Building rating system due to the long life cycle of building materials, as well as the different phases of operation and uncertainty of the end-of-life; each certification gives a different point of view regarding the use of this LCA perspective.
In terms of the life cycle of the materials, LEED followed a criterion mainly centered on the recycled quantities and use of regional materials without consideration of environmental assessment of materials, consumptions and hazardous substances until the last version LEED v4. It means, its new approach about LCA requests an Environmental Product Declaration (EPD) or another accepted method of reporting to reveal the mandatory LCA-based data.
BREEAM certification incorporates the environmental assessment of materials, with a specific LCA tool to counsel about the selection of materials. Integrates criteria about reuse of existing materials, components and with special consideration on the required documented origins. The life cycle study only refers to the construction materials and other life cycle stages, such as the operation/use or the demolition are not measured. The results are expressed in units such as kg CO2 equivalent and afterwards transformed into the categories. Apart from that, there is not criteria about hazardous elements.
Although, BREEAM and LEED are at this time the most used systems, European standards (CEN) are being developed with focus on economic and social sustainability on behalf of the German DGNB. DGNB includes evaluation of materials in the chapter of Environmental Quality, with focus on the entire LCA of building material usage and energy operation. In addition it also includes an assessment of the building containing hazardous substances. Concerning waste management of materials, DGNB assesses in the category of technical quality criteria for cleaning and maintenance to ensure longevity and criteria of how easy it is to separate materials by building alterations and demolition or the usage into new material alterations. DGNB has also a European Sustainable Construction database (ESUCO) LCA database based on EPD (EN 15804) that contains environmental data on over 500 construction materials.
Thus, despite of the overly complexity to develop complete LCAs for regular use, there is a growing demand of this aproaches in the stated GBCS that are also working to make it more accessible and easy to be used.