A Case Study on Sustainable Building

Table of Contents

• 1. Introduction
• Report Body
• 2. Principles of Sustainability
• 3. The Factors
  • 3.1 Energy Efficiency
  • 3.2 Water Efficiency
  • 3.3 Materials Efficiency
  • 3.4 Indoor Environment Quality
• 4. The Case Study
• 5. Analysis of The Case Study Performance
  • 5.1 Energy Efficiency
  • 5.2 Water Efficiency
  • 5.3 Materials Efficiency
  • 5.4 Indoor Environment Quality
• 6. Conclusion
• 7. Appendix
• 8. References

List of Figures

• Figure 1 the principles of sustainable building (EP minerals 2015) 3
• Figure 2 location Map of HCT Green-Nest Eco House (HCT 2015). 18
• Figure 3 sketch of ground floor & first floor (HCT 2015) 18
• Figure 4 double glazed window (HCT Green-Nest Eco house 2015. 35
• Figure 5 solar panels (HCT Green-Nest Eco house 2015).. 35
• Figure 6 Green Walls (HCT Green-Nest Eco house 2015) 36
• Figure 7 Indoor plants (HCT Green-Nest Eco house 2015) 36
• Figure 8 LED (HCT Green-Nest Eco house 2015) 37
• Figure 9 Insulated Concrete Form (HCT Green-Nest Eco house 2015) 37
• Figure 10 VRF System (HCT Green-Nest Eco house 2015) 37
• Figure 11 HRV System (HCT Green-Nest Eco house 2015). 38
• Figure 12 ashcrete. 38
• Figure 13 nudura walls. 38
• Figure 14 CLT wood. 39
• Figure 15 ferrok. 39
• Figure 16 water efficiency. 39

List of Tables              

• Table 1 rating energy efficincy according to LEED.. 9
• Table 2 rating energy efficiency according to BREAM 9
• Table 3 rating water efficincy according to LEED.. 11
• Table 4 rating water efficiency according to BREAM 11
• Table 5 rating materials efficincy according to LEED.. 15
• Table 6 rating materials efficiency according to BREAM 15
• Table 7 criteria of Indoor Environmental Quality According to LEED 2009 V₃ (USGBC 2017) 17
• Table 8 criteria of Indoor Environmental Quality According to BREEAM (BREEAM 2016). 17
• Table 9 HCT Eco-house – energy efficiency technologies (HCT 2015) 19
• Table 10 energy performance of HCT Green-Nest according to LEED 2009 (V₃) 21
• Table 11 energy performance of HCT Green-Nest according to BREEAM… 22
• Table 12 HCT Eco-house – water efficiency technologies (HCT 2015) 23
• Table 13 water performance of HCT Green-Nest according to LEED.. 25
• Table 14 water performance of HCT Green-Nest according to BREEAM… 26
• Table 15 HCT Eco-house – materials efficiency technologies Source: (Higher College of Technology 2015. 27
• Table 16  Materials performance of HCT Green-Nest according to LEED 2009 (V₃). 28
• Table 17 Materials Efficiency performance of HCT Green-Nest according to BREEAM… 29
• Table 18  HCT Eco-house – Indoor Environmental Quality Technologies Source: (Higher College of Technology 2015. 30
• Table 19  Energy performance of HCT Green-Nest according to LEED 2009 (V₃) 32
• Table 19  Indoor Environmental Quality of HCT Green-Nest according to BREEAM… 33

1. Introduction

Green building is a technique of developing the environment. It aids humans, the society, the ecological life, and the bottom line of builder. It is all about tailoring a construction and its location to the native environment, in a way to decrease consumption of the resource, whereas growth life’s quality. There are many kinds for green building which cannot be singular “look” around the world. However, resource efficient and natural benefits able to be highlighted in a construction; they also can be unseen inside any architectural project. As well, a sustainable building is not gathering of ecological components or a little piecemeal alteration of a previously designed average building.  These methods not only increase the cost of the building, but may also result marginal source savings at top. The real sustainable building uses a complete process to programming, preparation, designing, and building or renewing a construction and locations. It covers gathering often-interlinked cases like site and weather, constricting orientation and system, comfort ability and lighting, matters, etc. and enhancing all these features in well-organized strategy (Karolides 2002). 

The major aim of the case study is to provide the requirements and main reasons why the engineer should save the environment and how to build the perfect green building in the local area. The case study finds out the solutions which can be the most effective in Oman’s economy supported with a literature review and analysis. The case study contains an explanation of the concept and Basics of sustainability, how it developed through the time. The main factors of sustainability are identified and the importance of sustainability internationally, locally, and especially in Oman is explained.

For this purpose, a sustainable project in Oman has been chosen to simplify the idea of sustainability and evaluate its performance using an international assessment scheme for sustainability. As well as, introducing the chosen sustainable project in Oman, discussing, and analyzing using sustainable factors, supported with literature review and figures. The data were collected out of searching and reading articles, journals, books, and the help of websites, plus, visiting the sustainable site.

This case study explores the concept, basics, and process of green building, principle, the factors of sustainable building, and its importance in the world, Middle East and Oman. As well, introduce the chosen sustainable project in Oman, discussing, and analyzing using sustainable factors, supported with literature review and figures.

2. Principles of Sustainability

Over several previous years and until now, the world is thinking about how can balance between the demands of human beings and the capacity of the eco-system of the planet to achieve the goal of sustainability. Furthermore, the concept of sustainability respects three major sectors: environment, social and economic without affecting the quality of life for coming generations. That means, the world has to think about the environment besides caring about developing their economies. At the same time, the world need to think about the health and social status of people (Circular ecology 2017).

As a result of scientists’ efforts, the concept of sustainable development has several meanings and justifications. The most common definition was said by Brundtland Commistion which states that, “sustainable development is development that meets the needs of the present without compromising the ability of future generation to meet their own needs “(ibid).

Sustainable development is one of the common challenges that facing humanity in the world. It is important to know that the concept of sustainable development appeared in the 1970s at a time when manufacturing processes were increasing. In 1987, a report was sent by the Commission for the Environment and Social Development that contained one of the concepts of sustainable development, which is concerned with increasing development while taking into consideration the environmental aspect (Yalkner 2005).

Figure 1: the principles of sustainable building (EP minerals 2015)

Eco-houses have been evolving for many decades. As a solution of the main environmental issues that the world is facing such as, global warming, climate change, ozone depletion and deforestations etc. About 21% of all primary energy is consumed by residential buildings in United States which implicates cooling, heating, water heating, cooking and operating electrical devices. As a result, engineers think about eco- friendly residential buildings which consume less energy with exploit any residues produced by the building like reuse wastewater that is produced from the same house, use friendly materials with high efficiency and quality (Kruger and Seville 2013).

Green buildings are designed, constructed and operated on ecological principles that contribute to increasing the efficiency of the building to fulfill the aim of minimizing the negative ecological impact from buildings (ibid).

Therefore, the United States of America thought that it is impossible to achieve sustainability on its own, so it is necessary for the rest of the countries to cooperate and solidarity with them to maintain health and environment suitable for living. This partnership should be based on general Assembly Resolutions 44/228, which were agreed upon on 22-December- 1989 which was adopted when the countries of the world were hosted at the United Nations conference aimed at taking some necessary measures to solve the problems of environment and development. In Agenda 21, the significant problems of these days were clearly addressed, which were aimed at making the world ready to confront and challenge problems that the next century could face (United Nations Conference on Environment & Development 1992).

As a result of the importance of sustainability around the world, some organizations or systems have been established to measure the environmental impacts and the factors that need to be covered by each environmentally friendly building such as Leadership in Energy and Environmental Design (LEED), Environmental Environment Assessment (BREEAM) (Bernardi et al., 2017). This indicates the extent of interest and cooperation of regional and international countries to achieve sustainability goals.

In the Middle East, it has become clear that there are many charities, environmental organizations and other interested parties in the field of environment. Most of them are affiliated with non-governmental organizations and this is evidence of the reflection of the culture and interest of the individual and society in preserving the environment. At the same time, the efforts of the government in this field cannot be denied. Despite the many obstacles and challenges facing the countries of the Middle East in achieving the sustainability of buildings, but there is an important example of some Arab countries that have an active role in this sector like Qatar, Lebanon and the United Arab Emirates (UAE). These countries have developed greenhouses standers, and this is a sign of the importance of sustainability for the communities, the economy and especially for environment (Issa et al. 2015).

United Arab Emirates changed the building codes and regulations, which include both government and residential buildings through the promulgation of a law by Dubai Municipality in 2014, which stipulates that everyone is required to implement all specifications to maintain a sustainable environment in order to reducing energy consumption and improving the performance of the building, so this will improve the economy, quality of life improve people’s livelihood and well-being (Ibid).

Oman is rising at steady pace as an outcome of the strong government spending and the active economic execution. The markets and the infrastructures of Oman will increase greatly as the ministry is going ahead with massive scale infrastructures constrictions and centering on the industrial capacity’s development. The green building concept, while has been worked on by various countries, is very new to Oman. Meanwhile Oman is a successful country; it has several new projects under construction or on plan for building in store, which provides huge chance for the concept of green principles to be incorporated along with the development of the country. Therefore, it is intelligent to push the concept of green building quickly as possible into building industry to improve the chance of green building for the next new missions and projects (Powmya and Abidin. 2014). Between the years 2012 and 2016, the construction projects in Oman have increased annually 9.4%, and probably will extend till 2021. Hence, Omani government has decided to generally practice the green or sustainable construction to reduce the demand on water needs and energy, and to limit the environmental influences associated with the development and rapid construction. The Omani government is operating continuously in building extensive infrastructure projects (Safinia et al. 2017)

The benefits of eco-houses around the world and especially in Oman can be divided into three main parts; environmental, economic and social benefits:

• Environmental Benefits

The entire objective behind green building is to maintain our environment and prevent the reduction of the natural resource in our planet. When the sustainable replacements are built during each stage of the development of the project it facilitates:

1.      Reduction of emissions.	5. Saving of water.
2.      Control of the temperature.	6. Reduction of waste streams.
3.      Waste Reduction.	7. improvement in water and air quality.
4.      Protection of ecosystem.	8. replenishment natural resources.

• Economic Benefits

Sustainable building does not improve only the environment’s excellence, but it also supports a lot of economic effects as well. Of course, by reducing the consumption of energy, building with sustainable materials, and developing water competence, it results:

1.      Enhancement of building’s life cycle.	4.   Increase residents attendance and activities.
2.      Decrease operating charges.	5.      Increase property cost.
3.      Supports and helps the growth of the “Green Market”.

• Social Benefits

Well, when most of the economic and environmental benefits of the sustainable building are identified, the greenhouse’s social benefits are often not recognized. After developing indoor environmental goodness, you are able to:

1.      Improve health and comfort.	4.      Reduce stress on native infrastructure.
2.      Form the perfect pleasing environment.	5.      Upsurge the resident’s morale.
3.      Enhance employee productivity

The movement of the sustainable building is here and growing as the time passes, the benefits are unlimited over the future and it shall be more than what is expected on the present time (Design Build Blog 2011; Khan 2017)

3. Factors of Sustainability

These days, the importance of sustainable buildings has been increasingly acknowledged. Many architects have been designing green buildings, considering the essentials of the environment, society and economy (Avsatthi 2014). As has been mentioned before, there are many systems that have the responsibility to evaluate the environmental impact of the building. In this case study the sustainable building was assessed by using LEED 2009 and BREEAM rating systems. The building can qualify for four certification levels, for instance Certified (40 – 49 points), Silver (50 – 59), Gold (60 – 79 points) and Platinum (80 points and above) (USGBC 2017) (Furr et.al.). Creation of sustainable building depends on different factors. In this case study four factors have been identified as follows:

• Energy Efficiency

Energy efficiency is reducing the amount of energy that is consumed in houses by selecting appropriate equipment that has high efficiency and quality. Furthermore, demanded energy can be minimized by the building design itself (Kruger and Seville 2013).

3.1.1 Justification

As the Sultanate of Oman is famous for its relatively hot climate, it is noticeable that the demand for energy has increased as a result of the use of air conditioners continuously during the day. In addition, the use of electrical devices, which drain a lot of energy during the summer compared to other seasons therefore, lead to spend a lot of money on the payment of the electricity bill, besides the increasing of gases emitted (Atalla et. al 2016). In this case, this factor has a very important role in saving money, energy and keeps non-renewable resources to be available for future generations. Where, in the developed countries more than 40% CO2 emissions are produced from powering building, cooling and heating.  The purpose of designing energy-efficient buildings is to reduce the energy consumption as little as possible. Moreover, Energy efficiency in building is helping consumers to save money for a long time as well as it is cost effective. Also it can help to meet the targets of energy and the shortage of energy resources (Zhang and Cooke 2010).

3.1.2 Technologies

Most studies have proved that buildings have the possibility for improvement of energy efficiency ranging from 20% – 30%. This can be attained by optimizing the management system of the building, heating and cooling system, distribution of water and energy and lighting. Energy-efficient technologies examples are listed below:  

• Energy Generation:

1. Attaching solar panels to the building roofs.
2. Attaching mini-wind turbines to the walls of the building to generate electricity.

• Heating & Cooling Technology:

1. The use of energy in residential building accounted for 55% and in commercial buildings accounted for 35%. This energy goes to heating and air conditioning (HVAC) cooling. The building can be heated by recycling heat generated from electronic appliances.

• Lighting:

1. Lighting of houses accounts for 4% of energy consumption and in commercial buildings accounts for 30%. In the buildings, the good practice for reducing energy consumption are smart meters and light control. Smart meters help in identifying the solution for improving energy efficiency; because it works as an observer to know how and where energy is consumed in the building. Light control allows lighting to be turned off when no one is present; this is done because it contains a network of sensors (Smith n.d).
2. It is appreciated that 20% of world electricity is consumed in lighting. The demand for electricity can be reduced by 75% by using (LED) lighting, which is more efficient than traditional lights. Moreover, 60 million of plug-in hybrid cars can be charged up by using the saved energy which is produced from using light control technology and LED lighting (Zhang and Cooke 2010), (Kruger and Seville 2013).

• Insulation:

1. Designing green roof and green living walls to insulate heat, avoiding floods and absorbing water (Plant Connection 2018, Zhang and Cooke 2010).
2. Using windows of double glazing or triple glazing to prevent loss of normal heat (Zhang and Cooke 2010, Kruger and Seville 2013, SCS 2013).

• Level of Expectation

Table 1: Rating energy efficiency according to LEED.

Energy Efficiency – LEED 2009 (V3)
Category		Points
On-site Renewable Energy	·         1% of using renewable energy. ·         3% of using renewable energy. ·         5% of using renewable energy. ·         7% of using renewable energy. ·         9% of using renewable energy. ·         11% of using renewable energy. ·         13% of using renewable energy.	1 2 3 4 5 6 7
Enhanced Commissioning		2
Optimize Energy Performance		19
Enhanced Refrigerant Management		2

 Table 2: Rating energy efficiency according to BREAM.

Energy Efficiency – BREEAM
Category	Credits
Reduction of Energy Use and Carbon Emissions	12
External Lighting	1
Energy Monitoring	2
Energy Efficient Cold Storage	2

• 
  Water Efficiency

It is an important thing in our life to access clean water with the increasing development of sustainable buildings. for that, the strategies in sustainability have essential roles to save the environment and reduce the problems of water. (Bock 2013)

• Justification

This factor used to manage the balance between environmental defines and economic wealth. (Donoghue.2009). Gary water can be used indoor in the toilets and also for irrigation and other purposes outside the building. (USGBC 2017). the second point with increasing the water efficiency in the buildings which will reduce the load on public water source and wastewater. (Bock 2013).

• Technologies

There is a request for extending the resources of water in different uses and preventing pollution for that there are technologies could reduce the pollutions and save the water.

• Deploy Environment-Friendly Plumbing Fixtures:

1. Combine binary plumbing systems that use recycled water for toilet cleaning or greywater system that regain rainwater or other non-potable water for site irrigation.
2. utilize profuse-low-flush toilets and low-flow showerheads, then mean water-conserving supply grant to border wastewater which will help to conserve water (Green Building Advisor 2015).

• Use Non-Potable Water:

1. Set up recirculating systems to be used for the center of hot water allocation, and prepare heating systems for more distant locations (Matheson 2017).

• Environment-Friendly Irrigation Technologies:

1. Blend self-closing nozzles of hoses or state of the irrigation controllers.
2. utilize micro-irrigation mechanism for turf areas (Matheson 2017).

• Level of Expectation

Water Efficiency – LEED 2009 (V3)
Category		Points
Water Efficient Landscaping	·         Reduce potable water consumption for irrigation by 50%. ·         No potable water use or irrigation.	2 Points 4 Points
Innovative Wastewater Technology	·         Reduce potable water use by 50% ·         Treat 50% of wastewater and use treated water on site.	2 Points
Water Use Reduction	·         Reduce by 30%. ·         Reduce 35%. ·         Reduce 40%.	2Points 3 Points 4 Points

 Table 3: Rating water efficiency according to LEED.

Table 4: Rating water efficiency according to BREAM.

Water Efficiency – BREEAM
Category	Credits
Water consumption	5
Water control	1
Water equipment efficiency	1
Water leak detection	2

• Materials Efficiency

material efficiency is a description of uses of materials in green building if it is new or recycled. there are many advantages to use recycled materials they are very strong fast to build and reduce the landfill.

• Justification

To reuse constructing substances merchandise to limit call because of maiden materials and reduce waste, thereby lessening influences related to the extraction or processing regarding maiden resources. To make bigger require for constructing materials merchandise so much are extracted yet built inside the region, thereby helping the uses over original sources yet reducing the environmental impacts resultant from transportation. To minimize the usage and depletion of perfect frank materials to ensure long-cycle renewable materials all the materials used in the construction should be through replacing to them with swiftly renewable materials (USGBC 2017). Sustainable building reduce waste as they have not undergone extraction or processing stages before use locally-sourced materials are more sustainable because they reduce their environment impact by eliminating the need for transportation. (Sustainability Workshop 2016)

• Technologies

In the green building, the processes of construction respect the environment and save it and try to reduce the pollutions in different ways. moreover, it is economical and sustainable. green building is used a recycled material to improve our environment and use huge numbers of landfill (Legrand 2017).

• Recycled Plastic:

It is used in creating concrete that not only reduces the pollution, but reduces cost, weight of concrete and provide new ways to use landfill plastic. Moreover, it is used to make polymeric timbers for use in everything from table to fences (Green Building Solutions 2010).  Recycling plastic is supporting land fill space and saving of money. Recycled plastic can be mixed with virgin plastic (plastic never been used before) to minimize the cost without any sacrificing the performance. Recycled plastic can be used to create polymeric timbers which able to use for everything, such as picnic tables into boundaries, therefore saving the trees (Green Building Solutions 2018). Plastics can be used in construction due to their light weight and excellent insulating abilities, also because its superfine, airtight, and waterproof. Plastic has a good point in covering and insulating roofs, floors, and facades. Moreover, gutters, rainwater pipes, and flue gas outlets can be made with plastic. Plastic is also plays a good factor in manufacturing kitchens, bathrooms, doors, glazing spacers, pipes, building sheets, and plastic reinforces concrete, and in foundation (Sustainable Building with Plastic 2013).

• Wood:

According to architecture and design articles the home or work or school have been surrounded by wood influence the body and environment specially, (CLT) it is one of the strongest wood. (Hanley 2015)

1. Bamboo: is stronger than steel. It is lightweight and water resistant. In addition, it is easily grown that is making it one of the most cost effective in construction’s materials (kati 2012).
2. Cross Laminated Timber (CLT).Wood as a building material has obtained favour with many architects and builders. One of the modern technologies used is Cross Laminated Timber (CLT), a process that looks like plywood, but on a larger scale. As stated by the American Wood Council, the panels made of cross laminated timber are designed and completed from industrial dried lumber collected and stacked accurately at right angles and glued across their whole surface. They are practically strong as steel, keep their static resistance, shape stays forever, and allows the motivation of loads on every side (Hanley S. 2015).

• Ashcrete:

It is using fly ash by product of burning coal. besides, it is a concrete alternative uses ash instead of Portland cement. It is can replaced 97 % of traditional ingredients in concrete by recycled materials. (Peckenham 2016). Ashcrete or Fly ash able to be a cost-effective alternative for Portland Cement in several markets, which can be used as a primary material in bricks, blocks, and paving. Basically, Fly ash can be recognized as an eco-friendly product for the environment, due to its by-product and has less embodied energy. Fly ash also offered in two different colours, and colouring can be available at the work site. In addition, it needs low water ratio comparing to Portland cement and adjustability mush easier to use in cold weather. Moreover, it can be used as admixture due to the high workability. It reduces emissions of CO₂, heat of hydration, cracking problems, bleeding, and permeability (Rodriguez J. 2017).

• Ferrock

1. It offers a stronger alternative to cement manufacturing methods. Actually, it is a carbon negative cement which helps to reduce the amount of carbon emission. in addition, the construction is made with ferrock cement will be strong and will not need to repair or replacement (Mahendriyani 2016).

• Level of Expectation

Materials Efficiency – LEED 2009 (V3)
Criteria		Points
Recycled materials	·         10% of using recycled materials.   ·         20% of using recycled materials.	1 2
Materials reuse	·         5% of reusing materials.   ·         10% of reusing materials.	1 2
Certified wood	·         50 % of using certified wood.	1

Table 5: Rating materials efficiency according to LEED.

 

Table 6: Rating materials efficiency according to BREAM.

Materials Efficiency – BREEAM
Category	Credits
Life cycle impacts	1
Insulation	1
Designing for durability and resilience	1
Materials efficiency	1

• Indoor Environmental Quality

Indoor environmental quality indicates to the quality of building’s environment, especially with regards to the health, safety and well-being of the inhabitants. There are several criteria that determine the indoor environmental quality such as moist conditions, air quality and lighting (USGBC 2014, CDC 2017).

• Justification

Indoor Environmental Quality plays an important role in health, safety and efficiency of work for occupants who spend their time inside the building (Kruger and Seville 2013). The selection of indoor environmental quality factor based on the Oman future vision for 2020 which put emphasis on providing greater social and health care for the citizens as well as protecting the natural wealth (MECA 2015). The consideration of this factor can enhance the building occupant’s lives, provide comfort environment where people can perform well and feel relax.

• Technologies

Several measures are suggested to eliminate the indoor pollutants, and the new effective measures in this area will be mentioned below:

• Safer Materials:

1. Using building materials that do not contain (VOCs) volatile organic compounds or produce irritating or noxious odors like Khimji Paints (Muscat Daily 2015), Sadolin Paints (Times of Oman 2012) and Jotun Paints (Jotun n.d.).
2. Designing exterior entrances with systems of permanent entryway that can hold and catch dirt particles.

• Privacy of Acoustic and Comfort:

1. Using sound observing materials like thick carpet, furniture with thick cushioning, heavy and thick curtains, floor de-couplers and limp mass sheets (Gromicko 2018). Using sound isolation equipment that helps to reduce the impact noise such as using silentstep, which is working as a damping material (Castro 2016). In addition, designing an acoustic metasurface that consists of air cylinders or spheres impressed in water mold to control sound transmission in the applications of airborne (Gori et. al. 2016).
2. Using systems of masking sound.
3. Using ducts of big diameter with high velocity airflow.

• Value Aesthetic Concerns:

1. Providing windows that help for natural ventilation and views. Moreover, providing spaces that meet human needs (WBDG 2017).

• Providing Ventilation & Maintaining Acceptable Indoor Air Quality:

1. Implementing Energy Recovery Ventilation (ERV) and Heat Recovery Ventilation (HRV) systems (WBDG 2017). They are systems that can reduce heat loss, provide good ventilation and reduce indoor moisture (Level Org. 2017).

   • Level of Expectation

Indoor Environmental Quality – LEED 2009 (V3)
Criteria	Points
Low-emitting Materials	4 points
Increased Ventilation	1 point
Daylight and Views	2 points

Table 7: Criteria of Indoor Environmental Quality According to LEED 2009 V₃ (USGBC 2017).

Indoor Environmental Quality- BREEAM
Criteria	Credits
Visual Comfort	Up to 6 Credits
Acoustic Performance	Up to 4 Credits
Indoor Air Quality	5 Credits
Thermal Comfort	3 Credits

Table 8: Criteria of Indoor Environmental Quality According to BREEAM (BREEAM 2016).

2. The Case Study

Figure 2: Location Map of HCT Green-Nest Eco House (HCT 2015).

Figure 3: Sketch of ground floor & first floor (HCT 2015).

The selected case study in this paper is HCT Green-Nest Eco House which is located in the campus of the Higher College of Technology in Muscat. This building was one of the participants in the competition of the best sustainable building in Oman that was sponsored by Scientific Research Council Oman.It is a two-store building where the ground floor consists of a courtyard in the front side, a Kitchen, a Living Room, two dining areas, Majilis Room and a toilet. The first floor comprises a master bedroom, two bathrooms, two bedrooms and a balcony. That building occupies an area of around 396 m³ of land.

As a result of its distinctive characteristics of sustainable building based on the long-term plans of the Sultanate of Oman in the field of energy conservation and the replacement of non- renewable energy with renewable resources. This building has been awarded the first prize. Furthermore, it has an important role in increasing awareness among youth and developing their skills in this regard (HCT Green-Nest Eco house 2015).

The design of HTC Green-Nest building considered Omani architectural style influenced by the culture of the country aspects such as a distinct. It is worth mentioning that it is also equipped with a cooling system, ventilation, operating equipment and LED lights and others that are powered by solar energy. One of the other most important point of this building is its respect of   3R s concepts reduces, reuse and recycle. An example is the treatment of grey water to reuse again for other purposes like irrigation. There is a lot of vegetation surrounding the building, which can provide home owners with some agricultural products, and also contribute to providing a nice atmosphere outside the building and it can reduce the heat that entered inside this eco-house (HCT Green-Nest Eco house 2015). Next section will analyze the grade of sustainability fulfilled by this building by using the factors that are mentioned previously. 

3. Analysis of the Case Study Performance

This part will analyze and discuss the real performance of the chosen case study which is HCT Green-Nest Eco-house by taking in our consideration the international systems like LEED and BREEAM for evaluating the performance of building which are built on the basis of sustainable building construction principles.

• Energy Efficiency

The technologies that implemented in HCT Green-Nest regarding to energy efficiency factor and the benefits of them are illustrated in the table below. In addition, each technology will be discussed.  

Criteria	Technology used	Benefits
On-site renewable energy	Solar panels at the roof	§  100% of needing energy is provided. §  76 of solar panels provide enough clean energy for one year
Optimize energy performance	LED lighting system	§  Reducing energy demand by more than 60% §  Zero emissions §  Excellent bright §  Its lifetime about 50,000-80,000 hours.
	Double glazed windows	§  Providing natural sun light during morning time to minimize the demand of energy. §  Insulating heat from outside.
	Green walls	§  Reduce the heat absorbed through the wall
Enhanced refrigerant management	VRF system	§  Saving 44% of energy consumption

Table 9: HCT Eco-house – energy efficiency technologies (HCT 2015)

1. Solar panels: The main source of electrical power in HCT Green-Nest is solar energy; 76 solar panels were used in the roof of the building. It is worth mentioning that the solar energy which is generated by this approach can provide energy for one year. Furthermore, this technology can provide 100% of energy that the building need to operate electrical appliances and heat water. So, this applied technology has helped to increase the efficiency of the building’s energy (HCT 2015).

2. LED lighting system: Green-Nest building used LED lights instead of conventional lights, and this type has the ability to reduce more than 60% of consumed energy. This in turn contributes to improving the quality and performance of energy. One other benefit that this technology provides is the reduction of emissions of gases besides decreasing the consumption of energy. In addition, it can work at the same performance level during its lifetime which is about 50,000-80,000 hours (HCT 2015, Eartheasy 2014). Overall, it is a good option, but it may become better if the building provides lighting control technology to ensure that energy is not depleted when no one is present or during daylight (Smith n.d.).

3. Double glazed windows: HCT Eco-house used the technology of double glazed windows due to its performance has advanced significantly. It plays a role in optimizing the heat insulation of the building and therefore, reduced the demand of energy as well as saving money (HCT 2015). It is worth noting that another type of glazed windows may be preferable to be used in the HCT Eco-house than double glazed windows which is the triple glazed windows because of its great efficiency in energy conservation (SCS 2013).

4. Green walls: It is good that the green building has implemented one of the technologies used to insulate the external heat from inside the house thus leading to optimization of the performance of energy (HCT 2015, Plant Connection 2018). It can be observed that HCT Green-Nest designers considered the warm atmosphere in the Sultanate of Oman while designing the exterior walls of the building.
5. VRF system: It is worth mentioning that the Variable Refrigerant Flow System was applied in HCT Green-Nest. It has sustainable features like it consumes less energy compared with the HVAC system, less maintenance cost and less operating cost. According to York company website, VRF can save about 39% of energy that leads to increased energy efficiency (York 2016).

5.1.1 Energy Performance of HCT Green-Nest According to LEED 2009 (V₃):

HCT Eco-house has achieved excellent energy efficiency criteria. As table 10 shows, HCT Green-Nest was evaluated according to LEED rating system.  It got 7 points (excellent) in using renewable energy because it exceeded 13% of using renewable energy. This high performance was achieved due to the use of solar panels which covered 100% of energy needs. In addition, it got 19 points (excellent) in the criterion of optimizing energy performance because it implemented some technologies that reduced the demand of energy as mentioned before Moreover, the refrigerant management was enhanced through using the Variable Refrigerant Flow System because of that, it was rated to get 2 points (good). The criterion of enhanced commissioning was not rated high because HCT Eco-house’s performance is quite weak in this area.

Energy Efficiency – LEED 2009 (V3)
Criteria		Points	HCT Green-Nest Rating
On-site Renewable Energy	·         1% of using renewable energy. ·         3% of using renewable energy. ·         5% of using renewable energy. ·         7% of using renewable energy. ·         9% of using renewable energy. ·         11% of using renewable energy. ·         More than 13% of using renewable energy.	1 Point 2 Points 3 Points 4 Points 5 Points 6 Points 7 Points	ü
Enhanced Commissioning		2 points	–
Optimize Energy Performance		19 Points	ü
Enhanced Refrigerant Management		2 Points	ü

Table10: Energy performance of HCT Green-Nest according to LEED 2009 (V₃).

5.1.2 Energy Performance of HCT Green-Nest According to BREEAM:

According to BREEAM rating system, criteria of energy efficiency of HCT Eco-house was evaluated as shown in table 11. In reduction of energy use and carbon emission criterion, it got 12 credits (excellent) for the reason of using energy efficient equipment (A++) and low emission appliances. HCT Eco-house got 2 credits (good) in energy monitoring criterion due to the HCT Eco-house’s efficient monitoring of energy. In addition, the criterion of energy efficient cold storage got 2 credits (good) as a result of using Variable Refrigerant Flow System (VRF) which is characterized by sustainable features as mentioned before

Energy Efficiency – BREEAM
Criteria	Credits	HCT Green-Nest Rating
Reduction of Energy Use and Carbon Emissions	12 Credits	ü
External Lighting	1 Credit	–
Energy Monitoring	2 Credits	ü
Energy Efficient Cold Storage	2 Credits	ü

Table11: Energy performance of HCT Green-Nest according to BREEAM.

• Water Efficiency

Criteria	Technology used	Benefits
Innovative wastewater technology	Sequencing batch reactor (SBR) technology.	§  Cleaning 98% of wastewater in 6 hours.

Table 12: HCT Eco-house – water efficiency technology (HCT 2015)

1. Sequencing batch reactors: The HCT Green-Nest greywater system is working on a process to collect and filter the used water from shower, sinks, lavatory, laundry, and car washing water. to confirm the quality of the water released, an industrial grade filter used, and the treated water will be used for watering plants (HCT. 2015). SBRs or Sequencing batch reactors use an isolated pre-treatment unit to stop and hold the sold matter and biological aeration with settling tank. The small wastewater treatment systems are completing cleaning the incoming water up to 98%, with respect for Aquato system and Klaro E Professional (GRAF. 2018) (HCT. 2015). The most significant benefit of SBR is equalization, primary clarification and secondary clarification, with biological treatment can be achieved in only one reactor, moreover, easy to control and high flexibility operating, minimal footprint, and of course, saving the costs by excluding clarifiers and other apparatus. As usual, everything has disadvantages, and SBR technology may has a higher level of preservation related to conventional systems associated with advanced controls, automatic valves, and automatic switches, with the higher level of advanced technologies required compared to other systems, especially for large buildings. Also, a potential of discharging settled sludge or floating through decant stage with some SBR arrangements, and potential aeration devices plugging during particular operational cycles, considering the aeration system which used by the industrialist (EPA. 1999).
2. Watering system: since the houses especially in Oman have large gardens and areas, a watering system is a great technology to use, while keeping in mind the water outcoming from the SBR technology. The various drip nozzles and micro spray together with the water coming from graywater system, guarantee best distribution of water to provide separately each plant with accurate volume of water needed, plus, water timer control which represents efficient and intelligent watering technology. The timer works on scheduled plan according to the water requirement of the plants, this avoids duplicating the water needed per day or not watering at all. The technology places a huge importance on the careful collection of materials. Taking care to warrant ecological compatibility and avoid the using of substance like phthalate and metals which effect on the environment and health. The system gears itself accurately towards the requirements of your flowers, vegetable, hedges and bushes. The water provided is exact zones that need it, without waste, resulting it both ecologically friendly and economical for you, which will save your money (HCT. 2015; Karcher 2015).
3. Natural water-filtering of plants: there are several innovative technologies can be used beside SBR technology, which is the only used in HCT Green-Nest house. Natural water-filtering of plants, it is a form of bioremediation, which a number of scientists, engineers, and ecologists have learned to use for largeescale filtration of polluted water. ecologist John Todd developed consolidated environmental systems which treat sewage and wastewater by fungi, natural aquatic plants, and other organisms. These basically have been used in commercial scale operation, however, ecologists and studies show that this technology may be used for residents in the next few years. As the technology uses natural plants for filtering the water, this will reduce the cost of developing the efficiency of water, moreover, the technology from the environment to the environment which highly saves the ecological system, on the other side, it has very good acceptance from the community especially for the people works truly hard to reduce the use of fresh water (Rich S. 2014).

• Water Performance of HCT Green-Nest According to LEED 2009

As shown in the table below, according to LEED standards, if the innovative wastewater technology -SBR in our case- treats around 50% of the wastewater released and reducing the use of potable water by 50%, gets 2 points. Well, SBR system in HCT Green-Nest building has high percentage of treated water comparing to other technologies, with 98% treated water, which is almost double the value given in the standards. Thus, the greywater system in HCT Green-Nest takes 4 points.

Water Efficiency – LEED 2009 (V3)
Category		Points	HCT Green-Nest Rating
Water Efficient Landscaping	·         Reduce potable water consumption for irrigation by 50%. ·         No potable water use or irrigation.	2 Points   4 Points
Innovative Wastewater Technology	·         Reduce potable water use by 50% ·         Treat 50% of wastewater and use treated water on site.	2 Points	ü
Water Use Reduction	·         Reduce by 30%. ·         Reduce 35%. ·         Reduce 40%.	2Points 3 Points 4 Points

Table13: Water performance of HCT Green-Nest according to LEED 2009 (V₃).

5.2.2 Water Performance of HCT Green-Nest According to BREEAM:

As shown in the table below, according to BREAM rating system, HCT Green-Nest house got 5 credits in water consumption criteria. plus, one credit in water control because of the smart controlling system used. The SBR technology is efficiently perfect and manufactured with high quality materials which give it one credit in water efficient equipment. Otherwise, the house got no credits in leak detection because of not using any technology of this purpose. 

Water Efficiency – BREEAM
Criteria	Credits	HCT Green-Nest Rating
Water consumption	5	ü
Water control	1	ü
Water efficient equipment	1	ü
Water leak detection	2

Table14: Water performance of HCT Green-Nest according to BREEAM.

• Materials efficiency

Criteria	Technology used	Benefits
Recycled materials	Nudura wall system            Recycled furniture	–          Highly insulated concrete wall. –          Made of recycled materials   –          Achieving 3Rs Concepts (Reduce, Reuse and Recycle)
Insulation	Using of Polystyrene material	–          Well insulated material –          Reduce heat transfer

Table 15: HCT Eco-house – materials efficiency technologies Source: (Higher College of Technology 2015).

1. Nudura wall system: It is a highly insulated concrete wall, with no air spaces or studs. Nudura wall is very soundproof. If there an airport or any noises places. it will not be any sound to hear. it is very quiet, strong and fast to build. Likewise, it is built by ICF (international finance corporation). It is must keeping the Styrofoam on it to create insulation and thermal barriers with the concrete. All the webs are from recycled materials. It is about 70% of weight of the wall (Nudura 2017).
2. Polystyrene: To reduce the heat transfer from the ground 50 mm layer of polystyrene materials is used and floor is covered with locally available terrazzo tile. polystyrene is very widely used, and it is used to rigid insulation in HCT from the heat because it is wonderful moisture resistance, performance, and affordability. It saves the building from weather and the health of humans (Wilson 2009).
3. Recycled furniture: HCT Green-Nest used the furniture which is made from recycled materials especially wood. It is give retired materials a new and appealing attractive look. Actually, it has an important role in the environment. It has the ability of reducing waste materials that cause pollutants by applying the 3Rs Concept (Reduce, Reuse and Recycle) (City of Belmont 2017). As a result of that, there will be few manufacturing processes and few materials will be used (HCT 2015).

5.3.1 Energy Performance of HCT Green-Nest According to LEED 2009 (V₃):

According to LEED rating system, criteria of materials efficiency of HCT Green-Nest was evaluated as shown in table 19. In criteria of using recycled materials, it got 2 points (good) because of using Nudura Wall System. It is concrete wall with high insulation and it made of recycled materials. HCT Eco-house can reach higher performance if other alternative materials are used instead of cement in concrete such as fly ash which considered as waste. So it can achieve the 3Rs concept in effective way.  

Materials Efficiency – LEED 2009 (V3)
Criteria		Points	HCT Green-Nest Rating
Recycled materials	·         Uses 10% of the work   ·         20%	1 2	ü
Materials Reuse	·         5% ·         10%	1 2
Certified Wood	·         50 %	1

Table 16: Materials performance of HCT Green-Nest according to LEED 2009 (V₃).

5.3.2 Energy performance of HCT Green-Nest according to BREEAM:

As table 20 shows, HCT Eco-house was evaluated according to LEED rating system. It got 1 credit (good) in the criteria of using insulated materials as a result of using polystyrene material which has used in roof by 100 mm in thick which has the ability to minimize the transition of heat from the earth.

Materials Efficiency – BREEAM
Criteria	Credits	HCT Green-Nest Rating
Life cycle impacts	1
Insulation	1	ü
Designing for durability and resilience	1
Materials efficiency	1

Table 17: Materials Efficiency performance of HCT Green-Nest according to BREEAM.

• Indoor Environment Quality

The table 12 below shows the technologies that applied in Higher College of Technology Green-Nest Eco-house especially for Indoor Environmental Quality factor.

Criteria	Technology used	Benefits
Low-emitting materials	Insulated concrete form	§   Low toxicity §  Less emission of (VOCs)
	Jotun paint	§  Providing green building solutions (protective coating, fire proofing and no noisy smell and emissions.
Indoor air quality	Plants life &landscape	§  Help to reduce CO2 level §  Improving air quality
	HRV(Heat recovery ventilation )system	§  Purifying waste air §  Providing Oxygen
Daylight & views	Providing windows	§  Air purification §  Optimizing the atmosphere wind direction §  Maximizing natural light
Acoustic performance	VRF system	§  Low noise level
Thermal comfort	HRV(Heat recovery ventilation )system	§  Maintaining temperature among (25̊-27 ̊) and relative humidity in between (50-70)%

Table 18: HCT Eco-house – Indoor Environmental Quality Technologies Source: (Higher College of Technology 2015).

5. Insulated Concrete Form (ICF): The type of concrete that is used to build HCT Green-Nest Eco-house is Insulated Concrete Form (HCT 2015); it has the ability to resist fire approximately more than four hours (Building blocks 2018). So that can avoid spreading fire around the house. At the same time has made use of material with less emission so it will not harm occupant’s health. In addition, it does not cost physically and better than ordinary concrete (LOGix 2018).
6. Jotun paint: Jotun is the type of paint that is used in HCT Green-Nest, characterized by sustainable features that have been confirmed and tested by LEED 2009. It contains less toxic material compared with other type of paints. For this reason, people living in the building will not be exposed to diseases resulting from VOCs emissions (Jotun 2018).
7. Plants life &landscape: The building has beautiful plants that give elegance and comfort to those who are seeing them. In addition, those plants can have a main role in purifying air by minimizing Carbon Dioxide) CO₂ (level and increasing Oxygen) O₂ (.Moreover, the outside plants have a role in reducing the temperature of the earth and thus reduce the amount of heat that disturb the home. All in all, that will provide cool weather inside HCT Eco-house as a result of that will be no need to use cooling systems and that will help to improve people health.
8. (HRV) Heat Recovery Ventilation System: HCT Green-Nest has implemented one of the technologies used to increase the ventilation and to provide thermal comfort. It has used HRV system that can preserve the interior temperature between of 25co – 27co and the relative humidity between 50% – 70% (HCT 2015). It can maintain indoor air quality by ventilate fresh air. Moreover, it can provide appropriate movement and distribution for the air due to the proper location for indoor unit (HCT 2015, Level.Org 2017).
9. Providing windows: It is clear that during the design of HCT Green-Nest, was taking into consideration the suitable locations of windows to obtain natural daylight, allowing residents of the house to forgo using electrical lighting thus keeping their money that bayed on electricity. In addition to allowing air freshening, this makes people feel comfortable and gives them better health at their house (HCT Green-Nest 2015),( Responsible energy 2015).
10. VRF system: The VRF system that used in HCT Green-Nest is characterized by features that give the residents a comfortable feeling. This is because it is environmental friendly refrigerant and does not cause noise; this feature is not available in all air conditioners. In addition, it does not release toxic gases as a result of its active carbon filter that work to purifying the air before allowing it to distribute inside the house (HCT 2015).

• Indoor Environmental Quality of HCT Green-Nest according to LEED 2009 (V₃):

Criteria’s of Indoor Environmental Quality has achieved an excellent level in HCT Eco-house. As illustrated in table 13 the performance of the IEQ criteria is rated according to LEED rating system. It got 4 points (very good) in using low- emitting materials such as, Jotun paint which has been certified by LEED as a sustainable solution to solve the problems of environmentally friendly homes (Jotun 2018) in addition to use friendly type of concert  that called Insulated Concrete Form. It is possible to evaluate the building in terms of ventilation by giving it 1 point (good), as a result of using HRV (Heat recovery ventilation) system, indoor plants, landscape, and providing windows which all can help to purifying air and improving occupant’s health. Moreover, the criteria of daylight and views are rated as 2 point (good) because of providing windows in all rooms inside the building. 

Indoor Environmental Quality – LEED 2009 (V3)
Criteria	Points	HCT Green-Nest Rating
Low-emitting Materials	4 points	ü
Increased Ventilation	1 point	ü
Daylight and Views	2 points	ü

Table19: Energy performance of HCT Green-Nest according to LEED 2009 (V₃).

5.1.2 Indoor Environmental Quality of HCT Green-Nest according to BREEAM:

According to BREEAM rating system, criteria of Indoor Environmental Quality of HCT Green-Nest was rated as clarified in table 14. This building has got 6 credits (very good) in the criteria of Visual Comfort as a result of providing some plants inside and outside the house which gives a comfortable impression.  The Indoor air quality criterion was assessed as very good that has got 5 credits, this building was enhanced of this criterion by applied some technologies like: inside and outside plants, HRV (Heat recovery ventilation) system and providing window. HRV (Heat recovery ventilation) system was applied in this building to optimizing the thermal performance. As a result of that thermal comfort was rated as 3 Credits (good).

Indoor Environmental Quality- BREEAM
Criteria	Credits	HCT Green-Nest Rating
Visual Comfort	Up to 6 Credits	ü
Acoustic Performance	Up to 4 Credits	ü
Indoor Air Quality	5 Credits	ü
Thermal Comfort	3 Credits	ü

            Table20: Indoor Environmental Quality of HCT Green-Nest according to BREEAM.

6. Conclusion

This paper aimed to assess the sustainable performance in Oman buildings by looking at some factors and understands the principles of sustainability that must be presented. First section of this research was containing the main important concepts which are sustainability and sustainable development in addition to clarify the important of achieving sustainability in the world and Oman. It is worth mentioning that some factors ware illustrated with justify its important in Omani buildings with list some of relative technologies. Moreover, BREEM and LEED rating systems are used to evaluate and analysis the performance of the selected case study which is Higher College of Technologies Green-Nest Eco-House.

It turned out that this building has achieved three main principles which are economic, social and environment where it was found that this building has a high efficiency of energy, ventilation systems are able to create a comfortable and clean environment, and some recycled material use to make the furniture and other things. It is important to mention that the house works to recycle grey water to reuse it in irrigation purposes so by this way the water efficiency was achieved as a result of that we can say that this building is respect the 3Rs reduce, reuse and recycle. At the end this report was covers the concept of sustainability, the sustainable development, the important of achieving them in the world and Oman, factors of sustainability and analyses the selected case study by using some rating systems.

7. Appendix

Figure 4: Double glazed window (HCT Green-Nest Eco house 2015).

Figure 5: Solar panels (HCT Green-Nest Eco house 2015).

Figure 6: Green Walls (HCT Green-Nest Eco house 2015)

Figure 7: Indoor plants (HCT Green-Nest Eco house 2015)

Figure 8: LED (HCT Green-Nest Eco house 2015)

Figure 9: Insulated Concrete Form (HCT Green-Nest Eco house 2015)

Figure 10: VRF System (HCT Green-Nest Eco house 2015)

Figure 11: HRV System (HCT Green-Nest Eco house 2015)

Figure 12: Ashcrete

Figure 13: Nudura walls

Figure 14: CLT Wood

Figure 15: Ferrock

Figure 16: Water efficiency

8. References

• Zhang, F. and Cooke, P. (2010) Green Building and Energy Efficiency [online] available from < https://www.dime-eu.org/files/active/0/Cooke-2010-Fang-Green-building-review.pdf > [20 Nov. 2017]
• Mora, E. P. (2007) ‘ Life cycle – sustainability and the transcendent quality if building materials’. Journal of Building and Environment [online] 42, 1329-1334 available from < https://web.mit.edu/cron/Backup/project/urban_metabolism/TGOFF/readings%20and%20websites/lifecyclesustainabilitybldgmaterials.pdf > [20 Nov 2017]
• Kruger, A. and Seville, C. (2013) Green Building: Principles& Practices in Residential Construction. United States: Delmar Engage Learning.
• Furr, J.E., Kibert, N.C., Mayer, J.T. and Sentman, S.D. (2009) Green Building and Sustainable Development. United State of America: American Bar Association.
• Wilson, A. (2005) Durability: A key Component of Green Building [online] available from <https://www.greenbiz.com/news/2005/12/18/durability-key-component-green-building > [21 Nov 2017]
• Song, Y., Wu, S., Yan, N.N. (2015) ‘Control Strategies for indoor environment quality and energy efficiency’. International Journal of Low-Carbon Technologies [online] Vol. 10, issue 3, 305-312 available from < https://academic.oup.com/ijlct/article/10/3/305/703510 > [21 Nov 2017]
• Roisin, B. C. (2017) Apiece of Sustainability: Moisture Control [online] available from < https://engineering.dartmouth.edu/~d30345d/courses/engs44/moisture.pdf [22 Nov 2017]

• Avsatthi, B. (2014) Green Building Design and construction- 5 Factors Giving High Performance [online] available from < https://greenbuildingelements.com/2014/06/13/green-building-design-construction-5-factors-giving-high-performance/ > [23 Nov 2017]
• Bernardi, E. , Carlucci, S. , Cornaro, C. and Bohne, R. A. (2017) ‘ An Analysis of the Most Adopted Rating Systems for Assessing the Environmental Impact of Buildings’. Journal of Sustainability [online] Vol. 9, Issue 1226 pages (4 of 27) available from <file:///C:/Users/user/AppData/Local/Temp/sustainability-09-01226.pdf > [23 Nov 2017]
• S. Green Building Council (2014) Green Building 101: What is indoor environmental quality? [online] Available from< https://www.usgbc.org/articles/green-building-101-what-indoor-environmental-quality > [24 Nov 2017]
• Whole Building Design Guide (2017) Enhance Indoor Environmental Quality (IEQ) [online] available from < https://www.wbdg.org/design-objectives/sustainable/enhance-indoor-environmental-quality > [24 Nov 2017]
• Sustainable Construction Services (2013), Double & Triple Glazed Windows [online] available from < https://www.sustainableconstructionservices.com.au/products/double-triple-glazed-windows > [25 Nov 2017]
• Castro,V. (2016) Thermal and Noise Insulation Technologies You Should Know [online] available from <https://www.ennomotive.com/thermal-noise-insulation-technologies/ > [26 Nov 2017]
• Gromicko, N. (2018) Construction Method and Materials for Noise Control [online] available from < https://www.nachi.org/noise-control.htm> [27 Nov 2017]
• Gori, P., Guattari, C., Asdrubali, F., Vollaro, R. L., Monti, A., Ramaccia, D., Bilotti, F. and Toscan, A. (2016) ‘Sustainable Acoustic Metasurfaces for Sound Control’. Journal of Sustainability [online] available from <mdpi.com/2071-1050/8/2/107/pd> [27 Nov 2017]
• The Authority on Sustainable Building (2017) Energy – Heat and Energy Ventilation Systems [online] available from< https://www.level.org.nz/energy/active-ventilation/air-supply-ventilation-systems/heat-and-energy-recovery-ventilation-systems/ > [28 Nov 2017]
• Times of Oman (2012) Sadolin Paints shares vision of safer home [online] available from < https://timesofoman.com/article/2347/Round-up/-Sadolin-Paints-shares-vision-of-safer-homes- > [28 Nov 2017]
• Jotun (n.d.) Reduction of Solvents/VOC Emissions [online] available from< https://www.jotun.com/no/en/corporate/hse/jotun-greensteps/solvents.aspx > [29 Nov 2017]
• Centers for Disease Control and Prevention (2017) Indoor Environmental Quality [online] available from < https://www.cdc.gov/niosh/topics/indoorenv/default.html > [30 Nov 2017]
• Ministry of Environment and Climate Affairs (2015) Sustainable Development [online] available from < https://meca.gov.om/en/module.php?module=pages-showpage&CatID=21&ID=38 > [30 Nov 2017]
• Issa,N.and Albbar,S.(2015)’sustainability in the Middle East :achievement and challenges’ International Journal of Sustainable Building Technology and Urban Development [Online]available from<https://www.aesg-me.com/publications/sustanability-in-the-middleeast.pdf >[27-Dec-2017]
• Circular Ecological(2017)Sustainability and Sustainable Development – What is sustainability and What sustainable Development?[Online] available from < https://www.circularecology.com/sustainability-and-sustainable-development.html#.WlENLUWFUf0 >[27-Dec-2017]
• United Nations Conference on Environment & Development (1992)Agenda 21[Online]available from<https://sustainabledevelopment.un.org/content/documents/Agenda21.pdf >[27-Dec-2017]
• Higher college of Technology Green- Nest Eco house (2015)Oman Eco House Design Competition [Online]available from <https://www.hctgreennest.com/ .> [27-Dec-2017]
• Eartheasy(2014)LED light [Online]available in < https://eartheasy.com/live_led_bulbs_comparison.html >[2-Jan-2018]
• Smith,J.(n.d.)Lighting control technologies for energy saving [Online]available from< https://www.beka-schreder.co.za/files/beka/active/0/Lighting_Control_Technologies.pdf >[2-Jan-2018]
• Plant connection (2018) Benefits of Living Walls [Online] available from< https://myplantconnection.com/green-wall-benefits.php> [2-Jan-2018].
• Atalla, T. N. and Hunt, L. C. (2016) ‘Modeling residential electricity demand in the GCC countries’ Journal of Energy Economics [online] 59, 149-158 available from < https://www.sciencedirect.com/science/article/pii/S0140988316301992 > [2-Jan-2018]
• LOGix(2018)Logxic Insulated Concrete Form[Online]available from< https://logixicf.com/>[2-Jan-2018]
• Building Blocks(2018)Why Choose Insulating Concrete Form[Online] available From< https://buildblock.com/icfs/>[2-Jan-2018]
• Jotun(2018)Jotun Green Steps [Online]available from <https://www.jotun.com/no/en/corporate/hse/jotun-greensteps/energy.aspx>[4-Jan-2018]
• org. (2017). LEED credit library | U.S. Green Building Council. [online] Available at: https://www.usgbc.org/credits/new-construction/v2009/material-%26-resources [Accessed 31 Dec. 2017].
• org. (2017). Materials reuse | U.S. Green Building Council. [online] Available at: https://www.usgbc.org/node/1731020?return=/credits/new-construction/v2009/material-%26amp%3B-resources [Accessed 1 Jan. 2018].
• com. (2016). Green building � Ecological construction. [online] Available at: https://www.legrand.com/EN/green-building-description_12850.html [Accessed 2 Jan. 2018].
• Peckenham, E. (2016). 11 green building materials that are way better than concrete. [online] Inhabitat.com. Available at: https://inhabitat.com/11-green-building-materials-that-are-way-better-than-concrete/ [Accessed 2 Jan. 2018].
• Bock, p. (2013). The Role of Water Efficiency in Green Building. [online] Everbluetraining.com. Available at: https://www.everbluetraining.com/blog/role-water-efficiency-green-building [Accessed 3 Jan. 2018].
• com. (2017). ICF Alignment System. [online] Available at: https://www.nudura.com/divisions/nudura-products/icf-series/icf-alignment-system [Accessed 3 Jan. 2018].
• com. (2015). Green Plumbing Systems Save Water and Energy. [online] Available at: https://www.greenbuildingadvisor.com/green-basics/2d-plumbing-choices-incomplete [Accessed 2 Jan. 2018].
• autodesk.com. (2017). Green Building Materials | Sustainability Workshop. [online] Available at: https://sustainabilityworkshop.autodesk.com/buildings/green-building-materials [Accessed 1 Jan. 2018].
• Garden, H., Improvement, H. and Construction, G. (2017). 10 Technologies Used in Green Construction. [online] HowStuffWorks. Available at: https://home.howstuffworks.com/home-improvement/construction/green/10-technologies-used-in-green-construction.htm [Accessed 2 Jan. 2018].
• Hanley, S. (2015). Wood Building Materials Are Sustainable and Renewable – Green Building Elements. [online] Green Building Elements. Available at: https://greenbuildingelements.com/2015/05/03/wood-building-materials-are-sustainable-and-renewable/ [Accessed 1 Jan. 2018].
• greenbuild.org. (2012). Uses for Bamboo in Sustainable Building – www.greenbuild.org. [online] Available at: https://www.greenbuild.org/new-construction/uses-for-bamboo-in-sustainable-building/ [Accessed 1 Jan. 2018].
• Mahendriyani, D. (2016). Alternative building materials for green construction – Asia Green Buildings. [online] Asiagreenbuildings.com. Available at: https://www.asiagreenbuildings.com/14221/green-building-material [Accessed 29 Dec. 2017].
• Matheson, M. (2017). 11 Green Building Design Strategies and Measures. 6 Advance Water Efficiency and Conservation Measures. [online] Engineeringexchange.com. Available at: https://www.engineeringexchange.com/profiles/blogs/11-green-building-design-strategies-and-measures-6-advance-water [Accessed 1 Jan. 2018].
• Green Building Solutions. (2010). Recycling Plastics – Green Building Solutions. [online] Available at: https://greenbuildingsolutions.org/life-cycle-assessment/recycling-plastics/ [Accessed 18 Nov. 2018].
• Safinia, S., Al-Hinai, Z., Yahia, H. and Abushammala, M. (2017). Sustainable Construction in Sultanate of Oman: Factors Effecting Materials Utilization. Procedia Engineering, 196, pp.980-987. [Accessed 27 Nov. 2018].
• com. (2015). Corporate Responsibility & Sustainability | EP Minerals. [online] Available at: https://epminerals.com/sustainability [Accessed 27 Nov. 2018].
• Rodriguez, J. (2017). Uses, Benefits and Drawbacks of Fly Ash in Construction. [online] The Balance. Available at: https://www.thebalance.com/fly-ash-applications-844761 [Accessed 6 Jan. 2018].
• Green Building Solutions. (2010). Recycling Plastics. [online] Available at: https://greenbuildingsolutions.org/life-cycle-assessment/recycling-plastics/ [Accessed 26 Dec. 2018].
• Sustainable Building with Plastics. (2018). https://www.plasticseurope.org/documents/document/20130416115745-federplast_eng__1108_05_18_02_webversie_def_lr.pdf: Geert Scheys, p.34.
• Rich, S. (2014). GREEN BUILDING 101: Water Efficiency, Both Inside and Outside the Home. [online] Inhabitat.com. Available at: https://inhabitat.com/green-building-101-water-efficiency/ [Accessed 27 Dec. 2018].
• (2015). Watering System: Spray Gun, Sprinkles & Rain System. [online] Available at: https://www.kaercher.com/my/home-garden/watering-systems.html [Accessed 22 Dec. 2018].
• Wastewater Technology Fact Sheet. (1999). Environmental Protection Agency. [online] Available at: https://www3.epa.gov/npdes/pubs/sbr_new.pdf.
• Quigley, D., Heaney, G. and Odeyinka, O. (2018). Factors of Sustainability in building Design: Establishing Their Relative Significance. [online] Available at: https://www.arcom.ac.uk/-docs/proceedings/ar2012-1299-1309_Quigley_Heaney_Odeyinka.pdf [Accessed 27 Dec. 2018].
• Powmya, A. and Abidin, N. (2014). The Challenges of Green Construction in Oman. [online] researchgate. Available at: https://www.researchgate.net/publication/293123619_The_Challenges_of_Green_Construction_in_Oman [Accessed 17 Dec. 2018].
• Design Build. (2011). The Benefits of Sustainable Building. [online] Available at: https://thedesignbuildblog.wordpress.com/2011/04/04/the-benefits-of-sustainable-building/ [Accessed 21 Dec. 2018].
• Khan, Z. (2017). The Benefits of Sustainable Building. [online] Linked In. Available at: https://www.linkedin.com/pulse/benefits-sustainable-building-zeeshan-khan [Accessed 20 Dec. 2018].
• City of Belmont (2017) Reuse, Recycle, Reduce, Recover [Online] available from < https://www.belmont.wa.gov.au/Property/Pages/Reduce,Reuse,Recycle,Recover.aspx > [ 2 Jan 2018]
• Wilson, A. (2009). Polystyrene Insulation: Does It Belong in a Green Building?. [online] BuildingGreen. Available from < https://www.buildinggreen.com/feature/polystyrene-insulation-does-it-belong-green-building> [Accessed 2 Jan. 2018].