4- Model Set-Up
4.6 A close look at MBRHE case-study
As presented, in methodology chapter, the second selected case study belong to Mohammed Bin Rashid Housing Establishment Typical Villas project. The idea of this project is to allow citizen to own homes with affordable prices.
Five design options were provided with different sizes and exterior design perspective. The perspective design option of the selected villa is the modern style with total build up area 443.24 m². The total plot area of the any option is vary from site to other because it depends on the area of land owned by the client. According to their design the rest of any plot consist of parking area, walk paving and agricultural area.
The villa characteristics summarized in below Table 4.14. after assessing the project
architectural, structural and MEP drawing and documents. The proposed location of the case study will be in Al Warqa-4, near Tripoli and Nouakchott streets.
Figure 4.31: Monocrystalline PV panel property source: IES-VE software, 2019
Figure 4.32: Polycrystalline PV panel property source: IES-VE software, 2019
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Figure 4.34: The selected case study perspective view source: MBRHE
Figure 4.35: The selected case study plans source: MBRHE Figure 4.33: MBRHE case study site location source: Google Earth, 2020.
GF plan FF plan
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Table 4.14: Information of MBRHE Villa
4.6.1 MBRHE villa surrounding
As shown in Fig (4.33), the case-study proposed location surrounded by G+1 villa from three sides, one of them adjacent to it while the others located on the opposite side of the adjacent streets. Moreover, the backside of the site is open.
4.6.2 Vegetation and landscape
Like the SZHP case study, the architecture drawing of MBRHE presented that the villa is surrounded by a wide landscape area that will fill with natural soil.
MBRHE Building characteristics
Type of the building Residential “Private Villa”
Location Al Warqa 4 - Dubai
Occupancy 4 Adults and 4 children
Total Build-up area (m²) 443.25 for (GF area= 210.83 m² and 1st area= 232.42 m²)
Total height (m) 9.30
No. of floor G+1
Use of the areas
Majlis, Guest room, 1 kitchen, 1 Sala, 1 Living &
study room, 1 Maid room, 1 laundry, 1 Store, 4 Bedrooms, 4 Dress, 1 Family living and 7 Bathes.
External elevation area (G+1st) External window area (G+1st) Total Glazing/ External wall %
496.02 m² 59.91 m² 12.08% < 40%
Construction system Post lintel (column-beam) structural system
Figure 4.36: MBRHE setting out plan
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Mostly in Dubai, the housing sector's construction materials are the same; therefore, by looking into the architectural and structural drawings and construction documents, the MBRHE case study shared mostly the same construction materials but with different thickness or utilized other material as presented in Table 4.15. Regardless of the type of construction materials implemented, both cases study must comply with the building's local authorities’ regulations and rules.
By looking into the villa's structural drawing, the reinforced concrete is the standard material used in designing the estate's structural elements. As discussed with MBRHE engineers, the villa's external wall is made of a thermal block wall covered with plasters layer from inside and outside, where the exterior face is coated with a light reflective value higher than 75%.
At the same time, the internal wall is made of solid and hollow blocks, same as the previous case study.
External wall Internal wall
section
Figure 4.39: Typical wall section source: Dubai Municipality, 2020 Figure 4.38: Dubai municipality glazing regulation source: Dubai Municipality, 2020 Figure 4.37: Dubai municipality maximum regulation of U-value for external walls and roof
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The thermal blocks are composed of an insulation layer that is located between two
compressed concrete layers. The insulation layer that used in the villa block is polystyrene, with 60 mm thickness.
The combo roof system was also implemented in this case study but with a lower thickness of polyurethane insulation layer than the SZHP case study.
The double-glass window is the preferable window used in Dubai. It is part of the city regulations. It also installed it in all villa glazing elements but different thickness compared with the previous case study. For the frame, they used Aluminum material.
Similar to the SZHP villa, all wet zones are provided with a 60x60 gypsum board ceiling, located beneath the 1st and roof concrete slab, where the height of the ceiling is equal to 2.7m from the finishing material level. As shown in Fig (4.34), the architectural features of the modern style contribute a shading for the main entrance glazing elements.
Table 4.15: MBRHE construction material properties
Villa element Material Thickness
(mm)
Total U-value (W/m² k)
Roof
(Combo Roof)
Plaster layer Concrete slab Polyurethane foam Liquid coating (Polytex) Filter layer (Polyfab) Concrete screed SBR bonding agent
Top waterproofing coating
15 200 155 0.6
- 80
- 0.8
0.148
External Wall
Plaster
Thermal concrete block Plaster
15 200
15 0.46
Internal wall
Plaster
Solid blocks/ Hollow block Plaster
15 100/200
15 -
Ground Floor
Concrete slab Ground Concrete screed Tiles
100 70
30 2.98
90 1st Floor
Plaster Concrete slab Screed Tiles
15 200
70 30
2.5
Windows Aluminum frame with double glass layers separated with an air gap between them.
28
(8+12+8) 1.91
4.6.4 Main electrical appliance in MBRHE
The split unit air conditioning is the cooling system of the villa. According to their HVAC calculation, the maximum energy efficiency ratio of the unit = 8, which equivalents to 2.35 COP.
The lighting system drawings showed that the villa used two types of lightings the compact fluorescents lamp and LED light bulb (light emitting diode). The efficiency and the lifetime span of LED light is higher than incandescent and CFL. LED lamps can decrease the electricity consumption by 20% of the villa produced by lighting system.
Further, MBRH establishment installed solar collectors in the villa roof with 400-liter storage tank capacity, connected with two (2 kw) back up the electric heater.