Green Building

The rule of thumb for effective wind-driven cross ventilation suggests that the building length L should be less than five times of ceiling height H. This study uses a Large Eddy Simulation model and wind tunnel experiments to investigate the mechanism behind this rule of thumb. The numerical results reveal that the ventilation rate decreases as the building length increases. This is partly due to the pressure difference between the windward and leeward façades of long buildings (aspect ratio L/H ≥ 2.5) is smaller than that of a short building (L/H = 1.25). The other reason is owing to the internal friction, which can produce a sluggish zone with a low-wind speed inside the building. For buildings with aspect ratio L/H ≥ 5, the ventilation rate will be over-estimated, as much as about 20%, by ventilation models that do not consider the internal resistance. The location of the external openings can also influence the ventilation rate. When the openings are located in the opposite corners of the windward and leeward walls, also due to the internal friction, the ventilation was 15.5% less than that of openings on the centerline of the building. The mitigation effect of internal resistance on the ventilation rate can be quantified by a resistance model.

R&Sie(n)'s installation I'm Lost in Paris (2008), a disturbing take on the ecological house, epitomises the preoccupation of the French architect François Roche with the contradictions of modern nature. Javier Arbona tracks how Roche's notion of nature as ‘a partly human artifice’ which is both alien and personalised play out in his various projects, capitulating between attempts at overcoming alienation and heightening it. Copyright © 2010 John Wiley & Sons, Ltd.

"This paper describes a fire performance assessment of a sandwich panel
selected as the primary material in a high-performance house developed for the 2013
China Solar Decathlon competition. The sandwich panel has fiber reinforced polymer
skins and a foam plastic core. Evaluation of fire performance showed that the selected
panel would not comply with U.S. building code requirements for a single-family dwelling
without additional protection. However, the use of an intumescent fire protective
coating, coupled with the installation of a residential fire sprinkler system, is shown to
be effective in meeting the intent of the fire and life safety requirements of the International
Residential Code. Fire testing shows that the application of an intumescent fire
protective coating to the panels significantly decreases the heat release rate, the smoke
production characteristics, and the extent of flame spread on the panels."

The increasing attention to sustainability is pushing the construction sector to build more sustainable buildings. In this scenario, several sustainable development indicators have been proposed. The worldwide diffusion of sustainability rating systems and that of their structures are considered as proxy variables for the evaluation of sustainable constructions. Available rating systems span from energy consumption evaluation systems to life cycle analysis and total quality assessment systems. In these last systems, a multi-dimensional approach is proposed, as several building ratings are evaluated separately before being considered together. The description of assessment results from a sample of 490 buildings provides data to discuss construction characteristics that, currently, aim at being defined as sustainable. The paper shows that building energy performance is considered the most important criterion in sustainability rating systems, and the least achieved one in sustainability assessments. In contrast, other performance ratings of the building, such as water efficiency or indoor air quality, are achieved with a high rate of success in sustainability assessments.

Lime mortar is making a comeback in recent years due to the green building movement. However traditional quicklime based mortar has not had the benefit of extensive research and testing like concrete has for the decades it has been out of common use. Research done on concrete mix’s can be used improve the traditional lime mortar mix. In the course of this research, two distinct bonding mechanisms are examined, one carbonate based and one based on silica. This allows a concrete or lime paste to be optimized based on the aggregate used. As a result new lime based mortar mixes are possible and traditional quicklime mortars improved. Man made stone identical to natural stone is also discussed. The research also has implications for improving high strength concrete blends. Lastly the possibility of a new type of high strength concrete is explored that exploits the silica bonding mechanism.

""The LEED (Leadership in Energy and Environmental Design) standards of the non-profit U.S. Green Building Council have become the accepted benchmark for designating “green buildings” in the U.S. and many other countries. Throughout their ten-year history, the standards have remained flexible, changing with input from designers, builders, environmentalists, and others to incorporate new types of buildings and modify the existing standards to make them more geographically, economically, and functionally sensitive. In this paper, I examine through an urban political ecology lens how the LEED standards help to produce a particular kind of built environment.
Political ecology has broadened from its origins in the cultural ecology of the developing world to include urban and industrialized environments. In recent years, work in this area has focused on hybridity and socio-nature to explore the ways that urban environments are constructed and maintained through biological, political, and economic processes. Political ecologists have also shown sensitivity to the importance of scale in both the ecological and social constructionist senses. In this paper, I show how the LEED standards and the green buildings and built environments they help to produce are hybrids of material objects and human practices.""