A Study of Environmentalist Friendly Architecture and Green Buildings

Abstract

Green buildings are created to build a structure that is environmentally friendly and energy-efficient over its life cycle, which is surely essential in the construction industry. The question about effectiveness of Green building has been, nevertheless, debatable regarding the safety and design of the building. This research project will determine the efficiency, security and comfort of such construction by examining the main elements of Green building. The focus will be on the structural, industrial and financial position of building performance. Additionally, occupant satisfaction about Green buildings has been considered for research to analyze building condition in terms of regulations, acoustic and thermal comfort. This research was conducted using more than twenty sources of academic journals, books, and papers. The main elements of Green building include recycled and insulation materials, new wall-roof systems, and increased ventilation. It is shown that properties of recycled components and insulation materials can lead to moisture and mold problems and fire issues by presenting risks of building performance that can damage the building structure. As for the financial performance of Green buildings, it is estimated that green materials are more expensive than expected and can undergo financial loss because of the green rating standards. These arguments indicate that industry, performance and financial risks can be an obstacle to improve building performance and prevent these drawbacks of Green construction.

Introduction

In recent years, buildings with minimum impact on the environment are becoming more evident in the construction industry. These Green buildings are considered as current and the prospective view of the construction with the tasks to reduce harm to the ecology and the environment. To achieve these goals each element of the building will be created with specific products and systems instead of traditional materials. Although these elements are operated in a resource- and energy-efficient manner, their properties are undervalued and can lead to moisture and mold problems, which can be caused by poor and unsafe design. Some experts believe that new materials are sustainable and reduce negative environmental impact; however, towards the realization of such ecological construction, it can lose robustness and security of the building itself. Because the green materials are recently established, often there is less information about them and that can cause difficulty for owners and constructor. In addition, financial efficiency is not sufficiently reflected in the construction comparing with conventional housing. From the users’ view, sometimes their expectations about Green buildings are not totally justified. This research project will argue that despite the relevance of reducing negative environmental effects, Green construction may not be a quite productive way of improving buildings’ safety and design due to the performance, industrial and financial risks. This paper will focus first on the green materials and systems’ operation in the building, then consider the financial condition of the building, and finally, analyze occupants’ reaction about their houses.

Performance of Green building materials

Use of recycled and insulation materials for energy savings

One of the main features of Green buildings is using products which have no negative impact on the environment. Over the years, traditional materials such as steel, cement, glass, aluminum, plastics, and bricks have been used in the construction industry (Reddy 2004, 900). Moreover, these materials are easily available for buildings because their production companies are numerous and have been working for a long time. However, if traditional products were used considerably and continuously it would affect the environment adversely and reduce energy resources (Giama and Papadopoulos 2016, 92). Consequently, there is a high demand for replacing these materials by “green” components to solve such problems. For this reason, recycled products have an important place among green materials in reducing consumption of resources and energy. A considerable amout of natural resources can be saved using these components in the construction (Sun and Fang 2011, 90). Similarly, thermal insulation materials are also used as a major one of the structural elements of the building’s envelope in reducing thermal transmittance (Hidalgo and Welch 2015, 286). There are many types of insulation materials and it is used depending on the required applications in different building components (Rostam and Mahdavinejad 2015, 645). In Green buildings, carbohydrate-based foam insulation is applied for saving energy and it is increased to achieve better energy performance (Odom and Scott 2009, 20). Thus, these green materials are incorporated for resource and energy conservation in the construction.

Impact of green materials on building design

Green building materials can affect the structural design of buildings negatively despite the positive impact on the environment and energy. Experts say that implementation of new materials may present various difficulties for constructors and developers. According to Odom and Scott (2008), these products are mostly made by mixing synthetic and natural materials in a building envelope that can cause an increase of risk for moisture condensation. Furthermore, as they are produced fairly recently, there may be insufficient knowledge and unfamiliarity with the structure of products that can be the biggest challenge for construction (Hwang and Jian 2013, 276). For instance, in order to deliver the buildings with the required performance there is a need to understand permeance, water-related and other properties of the new products (Ibid). Moreover, together with new materials, use of recycling components may pose another obstacle for establishing sustainable building. Because they were reused in the new structure, they may not provide an ideal performance in water-shedding, which could improve the efficiency of condensation by causing the water to be repelled (Odom and Scott 2009, 20). In addition, these materials may not be effortlessly integrated into the adjacent new products (Ibid). After recycling, the qualities of existing components, such as flashing, rainwater barriers, and air barriers can be changed and perform in an opposite way (Odom and Scott 2008, 37). These materials may also lose their durability, quality and do not last for a long time due to their products which were already used and have completed their function in the construction (Hunag and Wang 2014, 355). That is why some characteristics of Green construction materials may present performance risks in terms of properties, qualities, and durability and may affect the buildings outcome adversely.

Coupled with recycled components, insulation materials may increase industry risks. Properties of expandable foam insulation materials are quite different from traditional insulation, that constructors used to apply in buildings. For example, some of the carbohydrate-based foam insulation products hold more water compared to the traditional hydrocarbon-based foam insulation (Odom and Scott 2009, 20). If retaining of water into insulation increases, it will affect negatively on the wall performance leading to moisture problems in the design because of their water absorption qualities (Ibid). In addition, the performance of insulation materials for fire security is an equally important issue in building management along with protecting the environment. Thermal insulation materials are mostly combustible and may compromise the fire safety design of the building (Hidalgo and Welch 2015, 292). The reason is an emitting of pyrolysis gas, which has the ability to ignite and releases flammable gasses contained toxic species (Ibid). Moreover, Chow (2003) mentions that using thermal insulation envelop materials as the main part of the walls in the construction of Green buildings might start up fire rapidly with 15 minutes. Such hazardous properties of increasing insulation might put in danger the whole building. Given these points indicate that the rise in the use of insulation products can lead to the poor performance of Green buildings and may contribute to fire hazards although it can maintain energy.

New systems of Green building

Use of wall systems containing insulated products

The roof and walls of the construction represent the important components responsible for excluding moisture in the building (Tobias and Vavaroutsos 2012, 45). Compared to the traditional buildings, load-bearing walls of Green buildings, which support the weight of the home above, become thicker for waste minimization benefiting in terms of energy efficiency (OECD 2003, 27). By contrast, such new wall system products involve unexpected problems related to moisture flows. For instance, the amount of condensation can be increased because of changing the course of moisture flows through the wall and roof system (Odom and Scott 2008, 39). As noted above, a new insulation material, which retains a large amount of water, is the main element of the wall system in Green buildings. The dew point in walls, the temperature at which dew forms, can change due to increasing insulation (Ibid 2009, 20). Because of that, condensation can be harmful and drying potential can be diminished, which may lead to loss of wall structure (Ibid). Also, this material is specially added into wall cavities and within the building interior making it convenient for sound mitigation (Tobias and Vavaroutsos 2012, 50). However, using this material, there can be formed an extensive amount of mold in wall cavities. To explain, if water were to flow through a water resistive barrier, wet-dry cycling process, which helps to maintain wall design, would not occur (Odom and Scott 2008, 39). Therefore, new wall systems of Green buildings with increasing insulation may damage the primary structure of construction.

The work of increased ventilation for Green construction

One of the main elements of Green building is increased ventilation, which provides convenience for building occupants. To reduce air pollutants, it is necessary to regulate the ventilation inside the building. According to the OECD (2003), the reason is that indoor air pollution has become the serious environmental issue regarding building activities as well as health problems. It is estimated that if ventilation of buildings is increased, the indoor pollutant levels could be reduced (Wei 2015, 14). Moreover, the majority of people spend as much as 90 percent of their time indoors, that is why a high degree of air pollutants is of particular concern (OECD 2003). Therefore, in Green buildings, designers focus mostly on good indoor air quality (IAQ) which is not only the prime element of the healthy building but also consists of building parameters such as comfort, lighting, acoustics and vibration (Spengler and Chen 2000, 568). In the way of achieving IAQ goals, the “stack effect” is considered as a significant phenomenon in the building design that enables a natural flow of the air during the summer and winter (Tobias and Vavaroutsos 2012, 64). With this intention, ventilation in Green buildings is increased to benefit from the “stack effect”, cooling air to the degree needed to assure occupant comfort and allowing hotter air to rise where it is exhausted (Ibid). Thus, increased ventilation helps to advance users’ comfort and buildings’ productivity.

On the other hand, increased level of mechanical building ventilation can lead to moisture problems, which is harmful to building performance. Usually, expanded ventilation is accompanied by a large movement of air from one side of the building to another (Chen 2000, 571). With this in mind, when huge amounts of air are shifted around the building, at the same time architectural elements of building confine the flow of air from the supply side to the return side of the air-handler equipment, the building can become unbalanced or partly depressurized (Odom and Scott 2008, 40). Furthermore, in hot and humid climates, increased ventilation causes an increase of humidity levels (Ibid 2009, 20). It indicates that Green buildings in the countries with humid summers can be more exposed to danger because of increased ventilation. Increasing ventilation, humid outdoor air will be absorbed into building cavities as a result of unexpected pressurization. This process mostly causes an increase of mold in wall structures that is emerged from condensation of humid air (Ibid). Moreover, Spengler and Chen (2000, 591) noted that the rise in the use of ventilation system consumes more energy due to their complicated procedure. Such techniques can affect the performance of the building in terms of energy saving. Accordingly, although increased ventilation provides comfort for occupants, for the most part, it can be risky for building performance by causing moisture and mold problems.

Financial condition of Green building

Compared to traditional houses, Green construction costs are higher than expected and hence it influences inefficiently the financial performance of the building. It is estimated that capital costs for energy efficient and ecologically friendly materials have risen by 10-25%, although the extra cost should not be more than 1% (OECD 2003). An increase in cost is followed by a complication of design in which green systems are integrated into projects. Furthermore, Hwang and Jian (2013, 275) state that Green building materials are much more expensive than conventional products due to their implementation and testing them using new construction technologies. It is calculated that the cost of green products is 4-10% more than traditional construction materials such as plywood (Zhang and Shen 2011, 169). Moreover, after construction, every Green building has to be certified and assessed with green standards, which focus on site, water, energy, materials, and indoor environment (Fischer 2009). Such certification process is based on required rating systems such as LEED, BREEAM and The Green Globes etc. (Durmus-Pedini and Ashuri 2010). If certification is not reached as expected it can lead to expenditure related to litigation between the engineer and the owner and tax incentives (Ibid). Thus, construction of Green buildings may derive financial risks due to the high cost of new green materials and integrated systems. Also, there would be a loss of financial income if the building did not perform as it was planned initially.

Comfort of Green building for occupants

Occupants’ satisfaction about Green building have not been wholly as favorable as everyone expected. Studies have reported that there are high discomfort issues for occupants of Green buildings. These buildings are usually dependent upon natural ventilation and natural daylight; therefore, occupants often feel too cold during the winter and too hot during the summer (Azizi and Wilkinson 2015, 191). Due to the high level of humidity and high temperature during summer people may be dissatisfied with the thermal comfort of building (Zuo and Zhao 2014, 276). Some occupants pointed out that without the control of the thermal environment inside the building such as temperature and ventilation is a significant concern of Green building (Ibid). People like to control and set up the conditions to their liking; however, excessive amount of choice is also annoying. Leaman and Bordass (2007, 668) claim that instead of expending time with building controls, occupants want to use them occasionally and when need them. Moreover, occupants are even significantly less comfortable with noisy environments (Gou and Prasad 2013, 159). Because of basic acoustic failings, people can hear others at a distance, but are unable to hear close colleagues properly (Leaman and Bordass 2007, 668). These situations indicate that some green building users do not agree with the promised benefits in terms of thermal comfort, control settings, and noisy environments.

Conclusion

Green construction has considerable drawbacks, which may affect adversely on building’s performance and improvement. Gaining benefits in one area can mean sacrificing performance in another (Odom and Scott 2008). Green building products are likely to benefit in resource and energy conservation, as they contain energy efficiency elements and recycled materials. Nevertheless, the qualities of these materials may not be entirely accommodated in the building structure and hence may present performance risks relating to moisture problems and short-term sustainability. In addition, flammability of insulation products cause industry risks with fire safety issues. A lack of information within the industry about recently implemented products demands Green building knowledge to be spread among project participants. As for ventilation systems, they may harm design of the building due to the emergence of mold. Indeed, public dissatisfaction about discomfort in terms of temperature and noise demonstrates that construction of Green building needs further efforts in its design. Additionally, the high cost of green materials and new systems leads to financial issues. To reduce such performance and industry risks, it would be better to organize expertise that plans building performance with new materials and products. Such expertise and shared experience may gradually enhance building architecture with green design and give an opportunity to enhance building in terms of energy saving and secure structure as well.