Transparent Facade using e-waste

The University of Sydney School of Architecture, Design and Planning

DESC9675 HIGH PERFORMANCE FACADES Semester 1, 2020

79&PARK / BIG Assignment 2 | Schematic Design Proposed by : SUJITH GOPAKUMAR DHANALEKSHMI

The University of Sydney School of Architecture, Design and Planning

Source: Laurian Ghinitoiu, www.archdaily.com

79&PARK STOCKHOLM, SWEDEN Bjarke Ingeks designed this apartment in such a way that the building blends with the urban context along with the greenery of the park on the south west side of the site.

The building looks like a wooden mountain with the nish of cedar wood cladding, the rooftops of cubicles are enriched with greenery using small tress and shrubs. The rooftops also act as a shared community gathering space for the residents. The cedar cladded residential units are arranged around the central courtyard at the ground oor giving more public access for the roads around the site. The prefabricated units enabled a exible design and construction process.

Project type: Residential Architects: BIG Architects Year of completion: 2018 2 Area: 25000 m No. of units: 196

Stockholm, the capital of Sweden experiences a moderately continental climate which has cold winters where the temperature falls below freezing point. Summer months are warm with a maximum temperature of 26 degree C.June, July and August are the warmest months of the year while its cold during the rest of the year. Precipitation is distributed throughout the year but not very high (530mm/year). Sun is rarely seen during November to January as the sun will be at the lowest altitude. o

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Winter: December to February (-3 C to 1 C) Spring: March yo May (-2oC to 4oC) Summer: June to August (11oC to 26oC) Autumn: September to November (0oC to 8oC) Figure 1: Orientation of the built form according for solar gain. Source: Author

DESIGN The main focus of the facade design and the form is given to the view from each unit towards the greenery of the open park on the south west side. This also enabled the units to get maximum solar gain from the sun as the sun path is inclined towards the o south. The maximum altitude of the sun to shine on the building is about 50 approx (Figure1). which is during the warmest month of the year. The south-west corner of the building height is lowered (7m) for maximum solar gain while the north-east corner is raised to 35m (gure 2).

Each module is of 3.6 m X 3.6 m size which is aligned and stacked like pixels. The walls are made of precast concrete panels and they are externally cladded with cedar wood panels vertically. The interiors are left exposed with the rough texture of the precast concrete panel (Figure 4), a few units are painted white with exposed structural systems (gure 5).

Figure 2: Inuence of sun path in the building form. Source: www.big.dk Figure 4: Rough-exposed interior nish. Source: www.big.dk

Figure 3: Temperature range of Stockhol, Arlanda . Source: Climate consultant

Figure 5: Painted interior nish. Source: www.thedesignchaser.com

FACADE BUILT UP 250 mm reinforced concrete 100 mm Extruded polystyrene 150 mm reinforced concrete Precast concrete panel Rooftop capping (Fig.13)

35 mm Treated wood batten

Cedar wood cladding

18 mm Cedar panel

Cube 3.6 m X 3.6 m

Figure 7: Plan. Source: Author

Metal end/corner capping

Cedar cladding Figure 9: Wall detail. Source: Author

Fixing bracket Thermal break

Roof

Flashing Glass Figure 14: Joinery of window to wall Source: Author Figure 8: Glass facade elevation. Source: Author

❷

Breathable membrane Vapor barrier Figure 13: Roof top capping for wall and cladding Source: Author

❶

Flashing Structural connection Figure 12: Vertical cladding joint Source: Author

Air seal

Air seal Closed to stop rain entry by gravity & kinetic energy 15 mm Drip and air seal Vertical rain gutter

Single pane 1.2 mm toughened glass with aluminum fame (wood nish)

Figure 6: Selected facade type for analysis.

Source: Author

Figure 14: Vertical joint of precast wall Source: Author Figure 11: Panel joint to main structure Source: Author

Figure 10: Wall vertical section. Source: Author

MANUFACTURING AND INSTALLATION

SOLAR PATH AND SHADING DEVICES

Sun during June 120 mm reinforced concrete

50o approx

50 mm Extruded polystyrene

Sun during December

Delta tie for holding 3 layers (Thermal break) 75 mm reinforced concrete

Curtain/blinds Figure 15: Exploded view Precast sandwich panel Source: Author

Figure 18: Schematic sun path analysis of 3.6 m X 3.6 m cube during summer and winter months with extreme temperatures. Source: Author

INSTALLATION OF PRECAST WALLS step 4

1)The panels are made as per required size.

The facade doesn't have any horizontal shading devices as the altitude of the sun is too low and solar gain is essential for keeping the interiors warm. The units are equipped with vertical shading devices and curtains to block unwanted glare. It is clear from the gure 18 that the sun Is barely seen during the winter months.

2)They are transported to site. step 3

3)The panels are installed over the structural framework (gure 16).

Vertical louvers in balcony to cut unwanted glare from western sun.

4)Roof is casted over the precast walls once they are structurally stabilized (gure 16).

Figure 16: Installation of precast sandwich panels at 79 & park Source: www.baltijasbetons.lv

Figure 19: Vertical lovers used in the second type of facade with balcony. Source: www.archdaily.com

Inserts for release hardwear Wyth (concrete) Step 1: Wall panels and roof Spacers Insulation

FIRE SAFETY Step 2: External cladding

Delta tie

MATERIAL Cedar Wood cladding

RISK

OPTION

MEDIUM

Alternate similar finish material for high raised

HIGH LOW HIGH LOW

Air seal Fire retardant additive -

Temporary support brace

Air gap External wyth (reinfor. Concrete) Extruded polystyrene External wyth (reinfor. Concrete)

Structural connection Step 3: Glazing Figure 16.1: Major components on sandwich concrete panel Image source: www.daytonsuperior.com

Figure 17: Construction phases of 79 & park Image source: www.baltijasbetons.lv

MATERIAL ANALYSIS WEST WALL (❷ in figure

SOUTH WALL

)

(❶ in figure )

Result:

PEAK LOAD WEST WALL

The isotherm image shows the impact of extruded polystyrene in preventing heat gain from the exterior environment.

The walls on the west and south which are exposed to sun light are analyzed for its performance. The west wall is a solid concrete sandwich wall with insulation has no windows or openings. The wall has an average weighted U value of 0.53 with a sessional U value of 0.132 (refer Apx .1) which proves to be a good performing wall as max U value for solid walls as per EU standards is 0.18 for Sweden(URIMA, 2018). The South wall has full height windows and it is assumed to be made of aluminum frames with thermal bridging and 11mm Pilkington microwhite ordinary glass for maximum solar gain during summer.

The peak load clearly shows that the heat gain during summer is moderate but the solar radiation is not adequate. Meanwhile the windows are responsible for 0.79kW of heat loss during winter.

There is a signicant heat built up at the corner due to the metal capping of wooden cladding.

Pros of the facade: - Good insulation.

- Minimal thermal bridging.

- Construction errors can be avoided.

Cons of the facade: - Time consuming as the construction works cant take place simultaneously.

- Wood cladding is a re hazard for high raised residential building.

The corner joints are conductive due to the presence of metal joiners and nails.

Figure 20: Therm analysis of corner Source: Author

79&PARK SYDNEY, AUSTRALIA MAJOR DESIGN CHANGES The original design by BIG was in response with the site in Stockholm which is a city in the northern hemisphere. To implement the same design in Sydney the orientation and the building fabric has to be changed to make the building more functional as the climate and the solar path is different in Sydney. The sun is mostly inclined to North in Sydney (Figure 21)hence the building morphology has to be changed for more solar gain, to accomplish that the height of the northern part is decreased while the southern corner has high raised structure (Figure 22). The materials are also changed to satisfy the Australian building codes. As per the code vertical cladding of wood is not specied for high raised building and hence that has to be avoided for building approval.

Sydney, the city has a humid subtropical climate with warm and hot summers and cold winters. The hottest month is January with a max temperature of 38oC while during the cold months of July and August the temperature can drop upto 2oC.The sky is clear during 35% of the year with a maximum solar radiation of 780 W/ m.sq and a minimum of 50 W/ m.sq. The city also experiences heat weaves during summer depending on the wind pattern of the desert at the center of the country. o

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Summer: December to February (25 C to 38 C) Autumn: March to May (14oC to 22oC) Winter: June to August (2oC to 17oC) Spring: September to November (11oC to 23oC) Figure 21: Orientation of the built form according for solar gain. Source: Author

BCA DESIGN REQUIREMENTS Building classication: Class 2, Type A Minimum re resistance: 1) FLOOR: FRL 30/30/30 2) Load-bearing wall: FRL 90/90/90 3) Non load bearing wall: 60/60/60 4) Insulation in the wall should be non-combustible Wind region: ZONE A (low risk)

DAYLIGHT The north-east corner is lowered to provide direct sunlight to the courtyard.

Figure 22: Inuence of sun path in the building form. Source: www.big.dk

SECTION J MINIMUM REQUIREMENTS: Max. Energy consumption (annual average) :15 kJ/m sq. hr** Max. Air permeability (building envelop) : 10 m.cube/hr. m.sq @50 Pa** Inltration rate: 0.7 air changes per hour (no mechanical system) or else 0.3 air changes per hour** Min. Energy rating: 6 stars Roof: Min R value: 3.7 Wall – Glazing construction: Max. U value 2.0

** for energy modeling

Patterns made of optical ber bringing interior lights out.

6% of the total surface area is optical ber.

Figure 23: Temperature range of Sydney, Australia . Source: Climate consultant Figure 24: Original facade. Source: www.archdaily.com

Figure 25: Night view of proposed facade. Source: Author

AIM OF THE FACADE Ÿ Ÿ Ÿ Ÿ Ÿ Ÿ Ÿ

Maximize solar gain during winter and reduced heat gain during summer from north facade.

Replace wooden cladding for re safety.

Reduced the construction time.

Maximize daylight in interiors.

Reduce the weight of the panels for easy transportation.

Reduce the impact on nature and energy consumption.

Reduce heat loss.

MODIFICATION TO ASSIGNMENT 1 FACADE Ÿ Ÿ Ÿ Ÿ Ÿ

The inner layer was made of rammed earth which is not viable for high raised building, it is replaced with concrete.

The optical ber panels were made separate and installed at site with iron frames, is modied into one single sandwich panel with insulation layer.

The proposal made in assignment one is not suitable for window punchers hence panel is reinforced for 79&Park.

Improved joinery details for better performance in high raised building.

The inner wyth made of reinforced concrete will act as a support structure for the wall which will hold the layers together and transfer the load to the main support system of the building.

BCA COMPLIANCE OF THE PROPOSED FACADE

Assuming density of: Concrete: 2242 kg per m3 Glass: 2500 kg per m3 Hempcrete: 280 kg per m3

Figure 25.1: Interior view of proposed facade. Source: Author

Structural connection

FACADE BUILT UP

Load transfer to slab.

Air seal

Figure 28 & 29 Concrete panel 300 mm Extruded polystyrene 150 mm Hempcrete 200 mm

15 mm Drip and air seal

Lime plaster 30 mm 1000 mm

Accommodates thermal expansion

Window offset 300 mm Metal shade (20 mm)

Figure 27: Plan. Source: Author

Figure 31: Structural connection . Source: Author

Optical ber Light diffuser

1000 mm

20 mm metal plate folded and bolted to stab.

Dip to prevent water Figure 32: Drip detail . Source: Author

Flashing Figure 28: North wall elevation. Source: Author

❷

Embossed pattern Optical ber 10o slope Light diffuser

❶

Gap for water run off Figure 33: Window bottom detail . Source: Author

Optical ber

Movement joints Vertical rain gutter

Figure 28: East wall elevation. Source: Author

Structural connection

Air seal Closed to stop rain entry by gravity & kinetic energy

Figure 30: Vertical wall section. Source: Author

Vertical rain gutter Accommodates thermal expansion

Figure 26: The proposed facade.

Source: Author

Figure 29: Vertical wall joint. Source: Author

MANUFACTURING AND INSTALLATION

SOLAR PATH AND SHADING DEVICES

Sun during January

300 mm reinforced concrete Diffuser for lighting

80o approx Bundled optical ber with re proong layer.

150 mm Extruded polystyrene

Sun during June

Optical ber Delta tie for holding 3 layers (Thermal break) 200 mm Hempcrete 30 mm Lime plaster

Figure 36: Schematic sun path analysis of 3.6 m X 3.6 cube m during summer and winter months with extreme temperature. Source: Author

Figure 34: Exploded view of wall panel composition Source: Author

INSTALLATION OF PRECAST WALLS ❶ 1)The support framework and roof is made.

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2)Frabricated wall modules are installed.

3)Windows are installed and gaps are sealed.

❷

For Sydney the building needs max solar gain during winter months (June -Aug), while the sun is at its low altitude inclined towards north. Double glazed window with low e coating will enable adequate solar gain from north. The area of the glazing is reduced to control the solar gain (explained in calculation). The window is offsetted 25 cm in from the exterior wall nish which will give a shading of 1.25m with 1m projection (Figure 27 & 28) The window on the eastern wall is not shaded as solar gain is minimal in the eastern side. Internal curtains can be used on both windows for additional glare prevention.

4)Interior works are done after wall structure is stabilized.

❸ Figure 35: Construction process. Source: Author

PROS AND CONS

FIRE SAFETY

PROS:

CONS:

- Customizable patterns.

- Lime plaster is durable and no need of additional cladding.

- Recycled optical ber reduces e-waste.

- Tunable insulation as per requirement.

- No need of additional insulation layer.

- The construction phases can happen simultaneously and hence faster completion. (gure 35) - Hempcrete is lighter than concrete.

- Optical ber brings more daylight to the interiors, thereby reduces energy on lighting.

- Effect of re on optical ber is not evaluated.

- The internal layer (concrete wyth + insulation) is thick (20% more than original) hence less usable oor area.

MATERIAL Lime plaster Hempcrete (Ext. wyth) Extruded polystyrene Reinforced Concrete (Int. wyth) OPTICAL FIBER

RISK LOW LOW HIGH LOW MEDIUM

OPTION Fire retardant additive Fire proofing layer

The material combination shows that the proposed facade is has less re risk than the original.

MATERIAL ANALYSIS EAST WALL (❷ in figure

NORTH WALL (❶ in figure

)

Wall panel is same for both facade, glazing is different for both windows.

The isotherm image shows the impact of hempcrete and extruded polystyrene, it keeps the interiors cool during hot days in Sydney.

)

Result: The east facing wall is installed with a small xed window for solar gain during early mornings. The window is single glazed with U value of 3.6 occupying an area of 1.5 m.sq including frames. The average weighted U value of the wall-glazing system is 1.2. Meanwhile the northern facade is installed with 6 m.sq window which is shaded by a 1m metal sheet. The window is double glazed and hence the wall-glazing system gives an weighted average U value of 1.37.

The peak load gained during summer on east wall is 0.63kW and on north wall is 1.58kW. At the same time 0.24kW and 0.26kW of heat is lost during winter from interior to exterior. The loss is not very high and hence the whole system can be considered as a good insulator for Sydney’s Climate.

There is a signicant heat built up at the corner but the heat is not transferred inside as the extruded polystyrene layer is placed at corner for better insulation.

Reduced conductive layers when compared to the original facade material combination.

Figure 37: Therm analysis of corner Source: Author

Wall panel is same for both facade, glazing is different for both windows.

REFERENCE Membrane, S. (2006). Details for GFRC Cladding Panels.

Fixings, G. R. C. (2012). Grc xings 03 .1.

GRCA. (2018). Practical Fixing Guide for Glassbre Reinforced Concrete (GRC). The International Glassbre Reinforcement Concrete Association (GRCA), (March), 100.

O'Hegarty, R., & Kinnane, O. (2020). Review of precast concrete sandwich panels and their innovations. Construction and Building Materials, 233, 117145.

Gerges, S., & Gkorogias, P. (2015). Civil and Architectural Engineering Concrete sandwich element design in terms of Passive Housing recommendations and moisture safety. 99.

Bida, S. M., Nora, F., Abdul, A., Jaafar, M. S., Hejazi, F., Nabilah, A. B., & Star, G. (2018). Advances in Precast Concrete Sandwich Panels toward Energy Efcient Structural Buildings. (October).

Reserved, A. R. (2018). U-VALUES. James Hardie. (2005). External cladding. Technical Specication, (September).

Guide, P. (2018). Cedar Cladding.

L. T. (2020). Installation instructions for Cedar cladding ABCB. (2019). NATIONAL CONSTRUCTION CODE VOL-1.

ABCB. (2019). NATIONAL CONSTRUCTION CODE VOL-2.

URIMA. (2018). U-values in Europe. Retrieved from https://www.eurima.org/u-values-in-europe/

APPENDIX

FORMULA USED System U Value - Area weighted average U system = As.Us + Af.Uf + Ag.Ug As+Af+Ag Where, As=Solid Area Af = Frame Area Ag = Frame Area Us=Solid U value Uf = Frame U Value Ug = Glass U value Peak load calculation Conducted heat: Qc = Uavg X ( T outside - T inside) X Area Radiated heat: Qr = SHGC X Dh X Area Apx 1: Sectional build-up calculation for original facade. Source: Author

Inď€ ltration heat: Qi = 1.2 X ( T outside - T inside) X V V = (Area X Air change)/3600 Total load (W) = Qc + Qr + Qi

Apx 2: Sectional build-up calculation for the proposed facade. Source: Author