ZAIRA BUTOOL ZAIDI
MSc, B.Arch, LEED Green Associate University of Sheffield, England
1. Residential Project in Zurich SITE STUDY
The site Plenty of mature trees next to the cafĂŠ, along the river.
The Casino building is significant because it is located directly across the river from the site. It is a 6 storey building.
Selnau railway station is an underground building located across the bridge from the site. ABOUT THE SITE AND ZURICH:
The Tamedia office building, built in 2013, designed by Shigeru Ban, is famous for its timber structure.
Country District Total Area Elevation Total Density Land use
Switzerland ZĂźrich 87.88 km2 (33.93 sq mi) 408 m (1,339 ft) 396,027 4,500/km2 (12,000/sq mi) 22% inhabited 30% woods 42% agriculture 6% lakes and rivers
SOLAR STUDY OF SITE Spring Equinox (group work)
Summer Solstice (group work)
Winter Solstice (group work)
Solar Study of the site in Autodesk Revit showed that there is very little overshadowing on the site which is good opportunity for the building to make best use of the sunlight available. But it could also mean overheating or glare caused due to too much direct sunlight. The building design needs to be informed by daylight studies and energy studies done to avoid overheating or glare.
The cumulative incident solar radiation on the southern faรงade is 800900kWh/sqm, whereas on the northern faรงade it is 300-500 kWh/sqm. The southern faรงade might need protection from sunlight, and can be a good location for solar panels, brise soleil, etc for solar power generation.
5 STEPS TO SUSTAINABILITY
VALIDATION Diagrams 3D views Daylight factor studies
VISION Energy studies Life cycle assessment
SOLUTIONS 1. 2. 3. 4. 5. 6.
Cafe + outdoor public spaces by the river. Provide balconies, decks, to connect with the river. Double aspect residential units and optimised glazings. Hybrid ventilation system. PV panels + ground source heat pumps. Provide solar shading on south faรงade.
To design a low impact, net positive building , connected with its natural surroundings and having good quality of natural light and ventilation..
CONCRETE OBJECTIVES 1. 2. 3. 4. 5. 6.
30% open and enclosed public spaces including green spaces. 70% spaces to have view of the river and green spaces. Daylight factors: Residences- 1.5%, Offices- 2% 50% dependency on natural ventilation. Building to produce 20% more energy than it consumes. Less than 10% of overheating risk.
PRIMARY OBJECTIVES 1. 2. 3. 4. 5. 6.
A building with vibrant open and enclosed public spaces. A building that is connected with its natural surroundings. Visual comfort- ample of natural light. A building with partial natural ventilation. A building that produces more energy than it consumes. No overheating risk.
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DESIGN EVOLUTION
In section
The process began with a simple narrow cuboidal shape of the height of surrounding buildings.
Some initial sketches of design evolution (author’s own)
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Functions were allocated to different floors keeping public areas like café on ground floor and private areas like residences on top floors.
The east façade is tilted at and angle such that residential areas get direct sunlight and office spaces get diffused and reflected sunlight.
Residences were given terrace gardens for direct visual connection with the river and to provide quite peaceful private greens to the occupants.
The final design gets optimum sunlight, has connections with the natural surroundings and has private as well as public green areas.
ENERGY CALCULATIONS 60% Glazing
THE BETTER OPTION 40% Glazing
To find out optimum glazing percentage for best energy performance, 2 options of 40% and 60% glazing were compared and the option with 40% glazing performed better in the energy analysis by a small difference of 12kWh/sm/yr in electricity EUI, but a considerable 230 MJ/sm/yr in Fuel EUI. Hence the 40% glazing option was chosen for further analysis.
Ground floor and mezzanine Gym + Cafe
ROAD
CAFETERIA
GYMNASIUM
OUTDOOR CAFÉ SEATING
The ground floor has Gymnasium and Cafeteria on it, split into ground and mezzanine, with the café having a part of it outdoors to allow for some spill out space and for enjoying the river.
The riverfront side of the ground floor, with more glazing than on the south, east or north façade, is getting more than 4% daylight factor. The mezzanine floor is getting 1-4% DF and the changing rooms do not get natural light but since it is not a habitable space, it can be accepted.
RIVER
3% 5-6% 2%
OUTDOOR LANDSCAPE AND CAFÉ SPILL OUT
CAFETERIA CAFETERIA
The café spill out space in plan
Existing space next to the café.
Visualisation after transformation.
Floor 3, 4 and 5 Morning render
Residences
There are 4 1-bedroom unit on 3 residential floors. There are 2 service cores and staircases per floor. The apartments are dual aspect making best use of the views and the daylight and natural ventilation.
Evening render
3% 5-6% 2%
The bedrooms have 23% and the living room have 1-2% daylight factor.
CAFÉ VISUALISATION AND ILLUMINATION STUDY
The café gets a lot of light from the river facing side (S-E). Louvers are installed on the glazing in order to provide shading in summer, but in winter, the solar gain is welcome in public spaces like a café.
RESIDENTIAL SOLAR STUDY
THERMAL MASS & NIGHT VENTILATION SUMMER COOLING
Underfloor heating Insulation Concrete slab
A typical concrete floor in the building.
DAYTIME ABSORPTION
NIGHT TIME FLUSHING (with open windows)
Concrete slabs have been used for floors which help in creating a thermal mass in the building. This strategy works on this site since there is significant variation in diurnal temperatures in Zurich. In summer, the concrete stores the heat during the day. At night, the windows are opened and the cool night air coming inside the building flushes out the heat that the concrete radiates at night. This phenomenon helps to naturally cool down the building in summer.
ACOUSTIC STRATEGY Noise issues in the building
Noisy streets adjacent to the building
Natural ventilation
SOLUTION- ACOUSTICALLY ATTENUATED VENTILATION PANELS
Aluminium louvres Insulation
Noise enters and gets absorbed by insulation Fresh air enters IN
Sectional view of the building highlighting the location of acoustically attenuated ventilation panels
OUT
Sectional detail of an acoustically attenuated ventilation panel
2. Mixed-use Project in Sheffield, UK SITE MICROCLIMATE STUDY A’
A’
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A The existing site. Site is located at the foot of a hill and has a river flowing south of it. Dominant issues are heat island effect and pollution.
The proposed massing on site. Shorter buildings are proposed to be in the front to allow wind to reach behind them to other buildings. Existing streets are respected and buildings are proposed along these streets.
Site section AA’ (topography from Google earth) showing building heights and the slope on site.
The street layouts and the microclimate The E-W streets are aligned with the slope of the site which is good for surface runoff and the N-S streets are aligned with the air flow plan of the site which helps in flushing out all the pollutants caused due to cars.
Figure showing variation in building heights for good air flow and solar access on site.
ZONING
BUILDING HEIGHTS
Plan showing building heights Buildings are arranged in a fashion of uneven heights to increase air flow and internal reflection between them.
25 floors 6-8 floors 2-4 floors
View showing building uses
PARKING AND GREEN SPACES
GREEN SPACES AND THE MICROCLIMATE GREEN ROOFS are added to the buildings of lower height for cooling effect on the site. The small empty spaces between the buildings are also interspersed with greenery.The green spaces also help in reducing pollution.
PARKING AND THE MICROCLIMATE Parking spaces are provided on the ground floor in some tall buildings and in some open spaces on the site. Because of good air flow on the site, the pollutants will be flushed out. View showing parking and green spaces
Green roofs and green areas Parking
IMPACT OF WATER
WIND FLOW ANALYSIS
Wind is predominantly blowing from South-West (SW) to North-East (NE). On very windy days, when the wind speed is 30-40 mph, then the wind will completely flush out all pollutants from the streets and even between the buildings. Since the heights of the buildings are kept varied throughout and short in the front therefore there will be no tunnelling effect. Pedestrians might experience a little discomfort but this happens on very few days of the year. On calm days with wind speeds 0- 10 mph, wind will still flow smoothly through streets and pedestrians will be comfortable.
COOLING EFFECT OF WATER The river flowing next to the site provides a cooling effect to a certain degree. It acts as a heat store, and also keeps the nearby soil moist which also cools down the site by evapotranspiration.
FLOOD RISK However, the site is in a flood risk zone because of close proximity to the river. Therefore, it is a good idea to place green roofs and green areas on the site to reduce flood risk. Instead of hardscaping all the empty areas like parking, etc., perforated materials can be used to reduce run-off.
Wind speeds
Frequency distributions
SOLAR ACCESS SOLAR ACCESS MICROCLIMATE
AND
Solar access is ensured to all buildings by making them of uneven heights, increasing internal reflection and splitting the buildings in levels. The proposed massing allows sunlight to reach all the buildings. Incident solar analysis can be seen in the adjoining figure that shows that all buildings receive adequate sunlight.
Incident solar analysis
B’ A’ B
A’
Plan showing sections for solar access study
Section AA’- showing solar access and internal reflection on site
Section BB’