A Green Building Envelope: A Crucial Contribution to Biophilic Cities - Biotechnologies and Biomimetics for Civil Engineering - page 133

forms and images into its buildings and cityscapes, and designs and plans in
conjunction with nature; it transform cities from gray and lifeless to green and
biodiverse (Beatley 2008 ).
Biophilic design is an innovative way of designing urban areas where we live,
work, and learn, creating healthy and productive habitats for city dwellers. It is
based on the theory of ''biophilia'' which contends that human health and well-
being has a biologically-based need to affiliate with nature.
While parks have often been a part of cities, architects and designers today are
incorporating nature into their designs through a variety of innovations such as
green roofs and vertical gardens, a renewed focus on local and natural materials,
and reclamation or restoration of spaces (Derr and Lance 2012 ).
This chapter will show within an ecological engineering context the impact of
green roofs and green façades in (dense) urban areas. An overview and comparison
of different types of horizontal and vertical green for housing, industrial, and other
commercial buildings will be given. Some concrete examples will be elaborated to
show possibilities of their multifunctionality.
There is a growing body of evidence of the positive physical and mental health
benefits associated with greenery and green elements in the built environment
(Beatley and Newman 2013 ). Realization of vegetated roofs and façades finds
more and more frequent application in the building sector; although for large scale
application, there is in general, still hesitation among policy makers and designers.
That is a great pity as financial details show that applications of green roofs are not
(any) more expensive than for example traditional flat roofs (Bohemen et al. 2009 ;
Köhler 2012 ).
Greening of outside walls or facades of buildings gains also more interest in
recent years. Although these concepts are not new (in the eighties of the twentieth
century, different reports and topics have been published, research into the use of
green inside cities increased substantially). In particular, the amount of publica-
tions, articles, and research focused on the use of green roofs and green façades has
increased in recent years (Köhler 2008 ). Despite the interest (under city dwellers,
architects, city planners, policy makers, and scientists) in a green building enve-
lope with corresponding positive claims, hard data about the effect of urban green
is sometimes missing or not well studied yet. However, nowadays the environ-
mental impact of buildings on the inner and outer climate becomes more and more
apparent.
Green buildings are designed to reduce the overall impact of the built envi-
ronment on human health and the natural environment. Buildings in which we
spend a great part of our life to protect us from nature's extremes, yet they also
affect our health and environment in countless ways (EPA 2010 ). Green building
strategies not only stand for sustainable materials in their construction (e.g.,
reused, recycled-content, or made from renewable resources), but also by using of
natural processes (e.g., shading effect of trees, insulation capacities of green roofs
and green façades, mitigation of urban heat due to evapotranspiration). The green
building strategy in the presented chapter focuses on one key aspect of the
''greening process'' namely the use of plants on and around urban buildings.