Civil Engineering Reference
In-Depth Information
management, renovation, demolition and utilization—built environment is affected
by various micro-, meso- and macro-level factors.
It is estimated that about 20 % of the US population suffers from asthma,
emphysema, bronchitis, diabetes or cardiovascular diseases and are thus especially
susceptible to external air pollution (American Lung Association
2005
). Outdoor
air quality plays an important role in maintaining good human health. Air pollution
causes large increases in medical expenses and morbidity and is estimated to cause
about 800,000 annual premature deaths globally (Cohen et al.
2005
). Much
research, digital maps and standards on the health effects (respiratory and car-
diovascular effects, cancer, infection, etc.) of outdoor air pollution, a premise's
microclimate and property valuation, have been published in the last decade.
These and other problems are related to a built environment's air pollution, a
premise's microclimate, health effects and real estate market value.
The imperative to reduce atmospheric carbon is well documented and one
significant area of production is from the built form which is responsible for up to
40 % of global energy consumption and 30 % of the world's carbon emissions.
Over the full life cycle of buildings, which includes construction and demolition,
80-90 % of this energy is used during the operational phase to heat, cool, venti-
late, light and run appliances. The balance of 10-20 % represents the embodied
energy and is consumed during the building process of construction and produc-
tion of the raw materials themselves. The need for the transport of goods and
services, delivery of water and waste services to and from buildings adds further to
account of emissions that the built form is responsible for and the total can be
described as the carbon footprint (Goodfield et al.
2011
).
Next, we present a few examples of components that comprise energy-efficient
built environment (energy carrier networks, pedestrian pavements in cities, trees
and the open green spaces).
Employing different energy carrier networks in connection with distributed
renewable energy generation is an attractive way to improve energy sustainability
in urban areas. An effective option to increase local renewable energy production
is to convert surplus electricity into, e.g., thermal energy (Niemi et al.
2012
).
Mendoza et al. (
2012
) examine the relevance of incorporating comprehensive
life cycle environmental data into the design and management of pedestrian
pavements to minimize the impact on the built environment. The overall primary
energy demand and global-warming potential of concrete, asphalt and granite
sidewalks are assessed. A design with a long functional lifetime reduces its overall
primary energy demand and global-warming potential due to lower maintenance
and repair requirements. However, long-lived construction solutions do not ensure
a lower life cycle primary energy demand and global-warming potential than for
shorter-lived designs; these values depend on the environmental suitability of the
materials chosen for paving. Asphalt sidewalks reduce long-term global-warming
potential under exposure conditions where the functional lifetime of the pavements
is less than 15 years. In places where it is known that a concrete sidewalk can have
a life of at least 40 years, a concrete sidewalk is the best for minimizing both long-
term primary energy demand and global-warming potential. Granite sidewalks are
