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 GreenNest 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.
Table10: Energy performance of HCT Green-Nest according to LEED 2009 (V3).
Energy Efficiency - LEED 2009 (V3)
Criteria
Points
HCT GreenNest 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
✓
Enhanced Commissioning
2 points
-
Optimize Energy Performance
19 Points
✓
Enhanced Refrigerant Management
2 Points
✓
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
Table11: Energy performance of HCT Green-Nest according to BREEAM.
Energy Efficiency - BREEAM
Criteria
Credits
HCT Green-Nest
Rating
✓
Reduction of Energy Use and Carbon Emissions
12 Credits
External Lighting
1 Credit
Energy Monitoring
2 Credits
✓
Energy Efficient Cold Storage
2 Credits
✓
-
1.2 Water efficiency
Table 12: HCT Eco-house – water efficiency technology (HCT 2015)
Criteria
Innovative
wastewater
Technology used
Sequencing batch reactor
(SBR) technology.
Benefits
▪
Cleaning 98% of wastewater in 6 hours.
technology
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).
1.2.1 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.
Table13: Water performance of HCT Green-Nest according to LEED 2009 (V3).
Water Efficiency - LEED 2009 (V3)
Category
Points
HCT GreenNest Rating
Water Efficient
Landscaping
•
Reduce potable water consumption for
2 Points
irrigation by 50%.
•
No potable water use or irrigation.
4 Points
Innovative
•
Reduce potable water use by 50%
Wastewater
•
Treat 50% of wastewater and use treated
Technology
Water Use Reduction
✓
2 Points
water on site.
•
Reduce by 30%.
•
Reduce 35%.
•
Reduce 40%.
2Points
3 Points
4 Points
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.
Table14: Water performance of HCT Green-Nest according to BREEAM.
Water Efficiency - BREEAM
HCT GreenCriteria
Credits
Nest Rating
Water consumption
5
✓
Water control
1
✓
Water efficient equipment
1
✓
Water leak detection
2
1.3 Materials efficiency
Table 15: HCT Eco-house – materials efficiency technologies Source: (Higher College of
Criteria
Recycled materials
Technology 2015).
Technology used
Nudura wall system
Recycled furniture
Insulation
Using of Polystyrene
material
Benefits
-
Highly insulated concrete wall.
Made of recycled materials
-
Achieving 3Rs Concepts (Reduce,
Reuse and Recycle)
-
Well insulated material
Reduce heat transfer
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).
2. 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.
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