Review and Critical Analysis of International UHI Studies

� Spatial Constraints and Suitability: Some cities do not have the space for extra trees and
green areas so the technology is not suitable; and green roofs are not always appropriate
due to gradient and positioning
� Lack of knowledge and awareness: public knowledge about green roofs is lacking and
opinions that roofs are faulty and problematic affects the credibility of the entire industry;
and
� Lack of research and standards: this is true for many countries outside of Germany,
although the German system could be used as a benchmark [212].
� Implementation of Building Codes: Codes are difficult to implement particularly for
retrofitting, an approach which combines building codes and incentive schemes could be
more successful;
Scale and Magnitude
Again, national policy does not exist across any country in the world due to the way
governments are structured. However, cities in Canada, Germany, Austria, Switzerland and
Japan have by‐laws which mandate green roofs on new residential buildings and new buildings
over a certain size. Studies are planned across North America to further analyze the benefits of
green roofs. These studies are being sponsored by city governments, public/private partnerships
and university research [214]. One paper encourages businesses, individuals and governments to
promote green roofs by example in order for benefits to be realized by a wider audience and thus
translate into policy [214]. It appears that setting an example at community level is the best way
to influence policy.
Conclusion
The most important barrier identified was the lack of research undertaken into areas outside of
cool roofs which results in poor public perception and cynicism. A way of combating this is to
publish more guidance and manuals to educate the public and those that could be involved in the
technology in its life cycle. A paper written by researchers at the University of Athens
acknowledges that education is an important issue in the success of a mitigation program and
aims to remove these barriers through the implementation of an action plan that targets a change
in behaviors, and promotes and transforms the technology market [200].
Another idea put forward by LBNL is that utility companies offer incentives to customers to
plant shade trees around their homes, the benefit to the utility is that in California utilities are
allowed to slightly increase their prices if they are seen to promote green projects and energy
savings and share the savings with their stockholders [066].
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