Follow us

SearchEsegui ricerca

Follow us

Keep you up to date!
Register now | Login

Residential Renovation towards nearly zero energy CITIES

The big picture is the greener picture

Life cycle analysis is a tool to evaluate the environmental impact over the life time of buildings 

The big picture is the greener picture

Life cycle analysis serves as a tool to evaluate the environmental impact over the life time of buildings and thus to improve their green performance beyond a mere reduction of energy consumption.

The building sector has become much greener. To get such credentials it has adopted methods borrowed from other industries, such as life cycle analysis (LCA), which looks at the environmental impact of a building at every stage from its creation to its decommissioning. “Taking a global view over the entire life cycle of a building avoids a shift of burden”, tells Katrin Lenz, an expert in LCA at the Fraunhofer Institute for Building Physics in Stuttgart, Germany.

This global approach matters because it gives a more accurate view on how green a building is.  “It is important to assess all measures for their global ecological impact over the entire life time of a building to ensure energy performance measures are not offset by other negative ecological impacts,” remarks Raphael Bointner, researcher at the Energy Economics Group, Vienna University of Technology, in Austria. For example, he adds: “Insulating buildings with Styrofoam is improving the energy performance.” But Bointner believes that LCA can be useful to put a number on such measure constitute a compromise as producing and recycling the material but also removing it after its life cycle comes at a cost for the environment.

Others warn of the limitations of such approach. “LCA is important to assess the ecological impact of new building materials and case studies,”  tells Hildegund Mötzl, head of research and development at the Austrian Institute for Building and Ecology in Vienna, “but results become quite predictable with the implementation of standard solutions.” For example, once a heating and ventilation solution for a case study has been established to be ecologically sound by LCA, this will hold true for similar buildings. Since many assumptions and average measures are incorporated into an LCA it will only produce general estimates. Mötzl therefore believes the considerable effort is not warranted for every individual building.

In other countries, such as the UK, the uptake of sustainable building solutions has been slow. And since building regulations are not as stringent as in Germany, for example, new financial mechanisms and information are required to provide evidence that sustainable buildings create high-value assets and are profitable, according to Mark Gillott, co-director of the Institute of Sustainable Energy Technology, Faculty of Engineering at the University of Nottingham, UK. He believes that the ecological impact derived from LCA can thus also be turned into information of economic value to help building developers know how their initial investments into sustainable technologies can be recovered in the long term. He points out “Investors need more accurate information about a development than the LCA of a prototype can provide.”

By contrast, in German speaking countries where the adoption of ecological building solutions has been better, experts are still seeking improvements. Bointner places his trust in local best practice models to stimulate the uptake of sustainable technologies in architecture. He coordinates the EU funded project AIDA, which aims to create local expertise in the building sector about near zero emission buildings (nZEB). This are designed to encourage local governments to take the lead. Private investors are expected to follow suit after they observe the cost savings made. Mötzl agrees: “besides regulations, the decisive factor to stimulate ecological solutions in architecture is creating local know-how and positive experiences.”

07 December 2012

By Stefan Grünert