The document discusses top lighting as a daylighting strategy. It defines top lighting as using openings located at the roof plane to admit daylight. It describes different types of top lighting like skylights, clerestories, and sawtooth roofs. Top lighting is well-suited for overcast skies and single-story buildings. Advantages include coordinated electric lighting and expressive building forms. Drawbacks can include visual discomfort from direct sun and lack of exterior views. The design process involves setting daylight factor targets, arranging spaces under roof openings, selecting aperture types, and adding shading as needed.

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2. Chapter 4

3. Chapter 4 1.4 Double Envelopes

4. Building and facade orientation Double envelopes: Are multiple leaf wall assemblies used in the transparent or largely transparent portions of a building façade Outer leaf Intermediate space Inner facade

5. Design Intent Maximize daylighting while controlling solar gain Reducing the need for mechanical cooling Increase the use of natural ventilation Increase acoustic isolation, especially in urban areas.

6. aesthetic Relationship of glazing to overall facade The glass wrapped facade used the glass panels as shingles on the building exterior. Glazed balconies in Venice, Italy

7. Thermal insulation Relationship of glazing to overall facade Outer glazing covers the entire surface of the façade at the Arup offices in London A “double skin glazed thermal buffer” curtain wall addresses solar heat gain as the project’s critical factor. Simply put, a shading device within the double skin absorbs solar gain and re-radiates it as heat trapped in the cavity

8. climate control Performance goals at the transparencies most double envelopes are designed to maximize daylight while controlling solar gain – a condition typical of office buildings dominated by internal heat gain . The interstitial space is used as a protected enclosure for operable shading devices that might otherwise suffer from wind damage and weather exposure.

9. active heating and cooling Performance goals at the transparencies Double envelope mitigate the surface temperature of the interior glass, reducing the mechanical intervention required to provide comfortable conditions under both and cooling modes The double envelope facade of Bayerische Vereinsbank Building in Germany has operable leaf glass louvers

10. Configurations: 4 main types Construction Strategies Box window Corridor facade Multi-story facade Shaft-box

11. Box windows Pre-fabricated curtain wall system Construction Strategies Kofmehl Building (Switzerland) Architect: SSM Architekten’s

12. Corridor facade Construction Strategies City Gate (Dusseldorf) Architect: Petzinka, Pink & Partners Pre-fabricated curtain wall system

13. Effective with regard to ventilation Incorporate service walkways of metal grating Construction Strategies Corridor Multi-story Victoria Ensemble (Koln) Architect: Thomas Van Den Valentyn

14. Shaft box Construction Strategies ARAG Turm, Dusseldorf Architect: Norman Foster

15. LEED Rating Energy and Atmosphere (35 points) Fundamental Commissioning of Building Energy Systems Minimum Energy Performance Fundamental Refrigerant Management Indoor Environmental Quality (15 points) Minimum Indoor Air Quality Performance Environmental Tobacco Smoke (ETS) Control Innovation and Design Process (6 points) Construction Strategies

16. Utilization Maintenance Requirements Efficiency of the façade can only be assessed in the context of the climate conditions of the site Each double façade must be tailored to the occupant’s function

17. Europe: Operable inner glazing leaf Control over outdoor air in the workspace North America: Interior hinge plate glass “ exhaust window” Maintenance Requirements

18. Factors to consider include: Facade cost Floor space available Compatible structural system Total building energy flows Size and complexity of mechanical plant Cost of long-term maintenance Double envelopes should be considered along with another strategy Considerations

19. Case Study Herz Jesu Church, Munich

20. Case Study Client: Archiepiscopal Ordinariat, Munich, Building Directorate Competition Architects: Karin Hengher, Olga Ritter Project Architects: Karin Hengher (Project Manager), Michael Frank, Annette Gall, Susanne Rath Competition 1996, 1st Prize Completed 2000 Objectives of using the double envelope strategy different colors and intensities of light shine into the church opaque glazing prevents views into the chancel from the outside

21. Case Study

22. Any Questions? If you are interested in this strategy you might want to consider the following literature: On the Typology, Costs, Energy Performance, Environmental Quality and Operational Characteristics of Double Skin Facades in European Buildings. Available: http://www.earthscan.co.uk/Portals/0/Files/Sample%20Chapters/9781844073894.pdf Double Skin Facades, Maria Wall Available: http://www2.ebd.lth.se/ebdhome/avd_ebd/main/personal/Harris/main/Double%20Skin %20Facades.htm Case Studies: Double FaçadeAvailable: http://www.architecture.uwaterloo.ca/ faculty_projects/terri/sustain_casestudies/ut4.pdf Case Studies: Double Facades in Germany Available: http://www.bbri.be/activefacad es/new/index.cfm?cat=5_example_building&sub=8_germany

23. Chapter 4 1.5 Green Roofs

26. Green Roofs are split into two categories: Extensive Intensive

27. Typically only suitable for grasses and small durable plants that love sunshine. Not so expensive Can work at slopes of up to 35 degrees, but require baffle systems to prevent soil slump if the slope is over 20 degrees . Growing media can be from 50 to 150 mm only.

28. Intensive Green Roofs have a deeper soil base Include larger plant diversities Can become a local Garden Growing medium should be 600mm+ Require a very strong structural system Large trees have to be placed directly on beams or columns Only flat roofed buildings.

29. Retain Storm Water and absorb it for recycling. Increase Thermal Resistance of a Building Reduce Urban Heat Island Effect Provide Pleasant Green accessible spaces for building occupiers.

32. Apply Insulation on the roof deck. Place a Waterproof membrane Root Barrier to block roots of plants. Drainable Layer Filter Membrane Growing Media

33. Green Roofs require appropriate solar exposure. Architect should consider the shading patterns produced by neighboring buildings and design the green roof accordingly. Integration with the building’s functions should be thought of. Type of Vegetation to use.

34. Determine the desired functions of the Green Roofs. Determine if an Intensive or an Extensive Roof is required Determine the amount of sun and shade that the proposed green roof area will receive during the year. Choose the types of plantation desired, taking into consideration rainfall, sun exposure and wind speeds Determine soil depth required depending on plantations chosen Estimate the dead weight of the green roof and therefore choose an appropriate structural system Consider incorporation of accesses for maintenance and irrigation

35. Green Roofs are quite expensive Require a very sound structural system Need constant maintenance and care for plants and growing medium Roofs have to be well insulated against drainage and leakage

39. Chapter 4 2.1 Daylight Factor

40. Daylight Factor

41. Definition :- Daylight Factor (DF): It is a numerical ratio used to describe the relationship between indoor and outdoor daylight illuminances ( typically under overcast sky conditions ).

42. Key Architectural Issues Design Factors:- Size of daylight apertures ( windows, skylights, etc.) Location of daylight ( sidelighting, toplighting, etc.)

43. Key Architectural Issues Design Factors:- Access to daylight ( considering the site, building and room contexts) Room Geometry ( height, width and depth )

44. Key Architectural Issues Design Factors:- Location of the point of interest relative to aperatures. Visible transmittance (VT) of glazing

45. Key Architectural Issues Design Factors:- Reflectance of room surface and contents.

46. Key Architectural Issues Design Factors:- Reflectance of exterior surface effecting daylight entering the aperature.

47. Key Architectural Issues Design Factors:- The affects of daylighting enhancements such as light shelves.

48. Key Architectural Issues Design Factors:- The buildings global location and prevailing climate. The time of day/ month/ year. The current sky conditions.

49. Implementation Considerations As a design criterion : using daylight factor as a target is straight forward approach; simply set DF criteria for various space that are appropriate to design context (a given DF target will represent different illuminances in different climate and at different times. DF criteria are often expressed as a minimum target. DF criteria may also derived from a design intent to displace (wholly or part) electric lighting. LEED established a minimum DF of 2% (with conditions ) as the threshold for a LEED daylight credit.

50. As a performance predictor : There is a number of methods used to predict the daylight factor such as : Scale models : that attempt to physically represent a proposed design. Computer simulations that attempt to represent a proposed design numerically. Other methods such as the 2.5H rule that suggest usable daylight will penetrate 2.5 times the window head height. As a measure of constructed performance : daylight factor is easily measured in a completed building with the use of paired illuminance meters.

51. Design Procedure Establish daylight factor criteria for the various spaces in the building being designed. Select the daylight approach or combination of approaches most likely to provide performance to match the criteria established in step 1. Size daylight apertures using available schematic design guidance or trail and error. Model the daylighting performance ( including daylight factors ) of the proposed daylighting system. Adjust selected daylighting design parameters ( aperture size, glazing transmittance, surface reflectance, light shelves, etc. ) as necessary to achieve established daylight factor criteria. Revalidate daylighting design modified parameters; iterate as necessary to meet design criteria.

52. Chapter 4 2.2 Daylight Zoning

53. Daylight Zoning The process of grouping various spaces in a building with similar luminous requirements into a day-lighting zone, thereby enabling design and control cost saving. Kuwait University College of Engineering Department of Architecture Design 4 Dr. Yasser Mahgoub Dhare’ah Al Nafjan 206111265 Nouf Al Bader 206111043

54. Daylight Zoning : According to Location and Orientation of a space.

55. Function Usage Schedule Location and Orientation Characteristics that should be taken into account when Combining Spaces to Create Zones are: Measured daylight zone in an office building

56. The Designer has control over the location and orientation of a space to maximize day-lighting, while function and usage schedule are based on the program.

57. Sometimes a space needs to be zoned with equal amount of light reaching both sides of the building

58. Factors to be considered in the zoning process Visual comfort Thermal comfort Fire and smoke control Building automation opportunities and requirements

59. Daylight zoning affects the building’s: Orientation Massing Plan layout and section Therefore, it must be a factor in the design process.

60. Maximizing the buildings Perimeter and the use of Top-Lighting for critical interior spaces optimizes daylight access for zones where lighting is needed.

61. Using an Atrium or Light Courts can also help in lighting the space.

62. Skin : Volume Ratio A building that optimizes day-lighting and natural ventilation would be shaped so that more of the floor area is close to the perimeter.

63. Daylight zoning can be difficult at times because the spaces cannot be grouped based on functions and times of usage due to the program of the building.

64. Not all sites allow Solar Access as a form of day-lighting because of the adjacent and circulation needs

65. To reinforce proposed daylight zoning schemes, the following should be considered and designed: Glazing Light Shelves

66. Shading devices on the external walls of a building can be used to decrease the amount of light entering the building Shading Devices

67. Design Procedure List and define the types of spaces that will be present in the building. Determine required light values for the various space types based upon the visual activities that will be performed. In a table, outline the usage schedule of the space and day-lighting potential of the space. Group rooms into zones based on similar lighting needs, matching schedules, corresponding uses, and thermal comfort requirements. Arrange building massing, plans, and sections to allow these zones to optimize daylighting potential. Verify the potential performance of daylighting strategies for each of the different daylight zones.

68. Measurement would show how far into the room will the side-lighting extent reach depending on how big the window openings are

69. Adjacency of a particular space will also affect the amount of light coming through the windows which will also affect the zoning of that space.

70. An example showing the combination of day-lighting and electric lighting in a computer area

71. A study made while planning a space to help show how affective day-lighting is with and without the use of electric lighting

72. Three distinct daylight zones: Reading Cubicles, Corridor and Stack Area

73. Chapter 4 2.3 Toplighting

74. Top Lighting Is a day light strategy that uses openings located at the roof plane as the point of admission for the surrounding daylight. TopLighted cault in musee de orsay ,Paris

75. Different types of top lighting: Skylight Clerestory Sawtooth Light scoop Roof monitor

76. Skylight musueem

77. Clerestory library cathedral Santa fe opera , interior of the theatre

78. Sawtooth

79. Light scoop

80. Roof monitor

81. Over cast sky- the weather where the sky consists of 95% clouds. Top lighting is an ideal strategy :

82. International Examples Arup Campus Solihull in Blythe Valley Park Dual function of roof pods seen from the inside and exterior

83. Bristish Museum

84. Mostly used in: Single story construction But if applied to multi story used in the upper most floor.

85. One story

86. Multiuse room with top lighting and side lighting to provide daylight distributions.

87. Advantages of top Lighting Top lighting is easily co-ordinated with electric lightening systems. Top Lightening allows for greater latitudes and how the walls of the space is used. The building becomes more expressive due to the additional form. Top Lightening adds great depth to lightening access to the building as lightening access is not limited to the walls. Thinking about top lightening makes us focus on the ceiling when it is usually neglected.

88. Comparing different top lighting scenarios

89. Drawbacks of top Lightening: Direct solar radiation can cause visual discomfort due to excessive contrast. Specifically for working environments. The desirable “dazzle” effect is required it is inappropriate in work areas. Top lightening is considered to be able to take place of side lightening yet not provide the view to the outside which is always wanted.

90. Design Procedure When comparing top lighting with side lighting, one can say that top lighting is the more selected approach But this does not mean that we can’t have both systems together. Here is how the procedure goes. Establish target daylight factors for the various spaces and activates to be top lit. 2) Arrange the building spaces and floor plan layouts so that those areas could have roof exposure and then be top lit.

91. 3)Determine what type of top lighting aperture eg (sky lighting, clerestory etc), is most appropriate for the space, building orientation, sky conditions and climate. 4) Evaluate different glazing options for the aperture (which is an opening in which the light travels in). Glazing should have:- -VT ( high visible transmittance) - SHGC ( in hot climates a low solar heat gain coefficient), so as to minimize sloar heat gain

92. 5) Estimate the size of daylighting apertures. A=((DFavg)(Afloor))/(AE) A being the required area of aperture,ft2(m2) DFavg being the target daylight factor Afloor being the illuminated floor area, ft2(m2) AE being the Aperture effectiveness factor 6)Arrange surfaces adjacent to the top lighting aperture to diffuse entering light to reduce contrast and distribute daylight throughout the space. 7)Evaluate the need for shading for top lighting apertures and design appropriate devices to provide necessary shading.