design tips for green roofs and vertical greening in schools...source: hong kong herbarium & ....

1 1

Design Tips for Green Roofs and Vertical Greening in Schools

Environment and Conservation fund Sharing Session cum Exhibition of Environmental Education and Community Action (EE & CA) Projects (General and Minor Works Projects)

6 June 2012

Kathy Ng 伍芷筠

Head of Greening and Landscape Office

Greening, Landscape and Tree Management Section

Development Bureau

發展局綠化、園境及樹木管理組

綠化及園境辦事處綠化及園境辦事處

Development Bureau, HKSAR Government ©Cumberland Presbyterian Church Yao Dao Primary School

Source: SP Ng

ytchowText BoxCopyright Notices: For the copyright of this presentation, please read the Important Notice in Greening website (www.greening.gov.hk). Besides, the copyrights of third party's photographs and diagrams rest with the sources as specified. If you wish to use or reproduce these photographs and diagrams for any purpose, please seek the permission of the copyright owners directly.

2 2

Benefit of Green Roof and Vertical Greening

• Environmental benefit– Contribute to the amelioration of

the urban heat island effect– Vegetation and soil can take up

some gaseous and particulate air pollutants to make air clean

– Noise mitigation: soil layers and plants absorb sound energy

– Improve stormwater quality to reduce water pollution for receiving water bodies

3 3

• Economic Benefit– Reduce air-conditioning energy

cost from green roof cooling effect– Reducing sun exposure for

building surface to extend roof life – Green roof can protect the roof top

material, especially the thermal insulation layer and the waterproofing membrane


SAVE $$SAVE $$

4 4


• Education value– Green roof attract wildlife and bring

biodiversity to school for students to experience

– Student can learn the knowledge of Eco-system from observation for the relationship among creatures

– Learn 3-R concept from using different recycle materials and making organic fertilizer from waste food / irrigation from waste water

– Organic farm for students to experience plant growing process

5 5


• Academic and health benefits– More open spaces can encourage

students to join outdoor activities to bring improvement in health and physical fitness

– Students tend to be more attentive in class, work harder, and better in academic performance

– Less attention deficit disorder (ADD)and play truant

6 6

Considerations

Technical Feasibility Funding

ObjectivesMaintenance

7 7

Considerations – School objectives

– Recreational / leisure space for students

– Outdoor classroom – hands-on experience

– Living classroom for monitoring studies from observation / experiment

– Education value– Amenity value

8 8

Considerations – Technical feasibility

• Usable Area– A large clear flat roof >200m2 is

preferred– Not heavily shade by adjacent

buildings– Rectangular and simple shape

is preferred– No limitation – design to suit the

siteSource: Ng Yuk Secondary School

9 9


• Structural Loading– Choice of Intensive /

Extensive Green Roof– Soil depth– Consult structural

engineer/ check drawings– Min. of 3kPa of load-bearing

capacity is recommended (300kg/m2)

– Loading data should be obtained

(Source: Urbis Limited)

IntensiveAMENTITY PLANTING

TOPSOIL (300-1500mm)

FILTER LAYER

DRAINAGE AGGREGATE (100mm)

PROTECTIVE SCREED (30mm)

WATERPROOFING

STRUCTURAL DECK

ExtensiveLOW MAINTENANCE GROUNDCOVER

LIGHTWEIGHT SOIL (80-150mm)

FILTER LAYER

DRAINAGE LAYER (30mm)

PROTECTIVE LAYER BOARD (5mm)

WATERPROOFING

STRUCTURAL DECK

10 10


• Accessibility & Safety– Access should be easy and

safe without obstacle– Evacuation for emergency– Universal accessibility – Parapet wall - building

regulations and safety requirement

– Robust railing / fence for safe use

11 11


• Waterproofing / Drainage / Irrigation– Rectifying water leakage if any– Waterproof membrane

installation– Surface drainage channel and

pipes should be able to drain water efficiently

– roof surface should slope > 1.5%for water flow to the drain

– Water supply for irrigation/ rain water retention

– Manual / auto irrigation

12 12

Considerations – Funding

• Budget for construction and maintenance– Intensive / extensive green roof– Recycle material for simple

green roof– Students - resources– Out source to competent

contractor for design and construction

– Plant selection– Irrigation system installation

Source: Ng Yuk Secondary School

13 13

Considerations – Maintenance

– Mowing - turf– Removing weeds– plant health care/ pest/

disease control– Fertilizer – when app

when appropriate/ nutrient fixing plants/ organic fertiliser

14 14

Typical School Green Roof

More possibilities!!More possibilities!!

Design Features for Green Roof and Vertical Greening

Source: C.Y. Jim, School Green Roof, Ng Yuk Secondary School and Munsang College Primary School

15 15

• Screen off railing, pipes and utility for amenity

Railing and plastic twine to guide climbers to grow

Simple but effective


16 16

Source: http://www.japanfs.org/

Green Roof Design Tips – Vertical Greening

Source:http://weblogs.baltimoresun.com

Climbers can grow well in planter boxes and climb up to fences / railings intensively

Plastic bag planters hang on fences can also create vertical greening in times

Design Features for Green Roof and Vertical Greening• Screen off railing, pipes and utility for amenity

Plastic bottles hanged in wood frame vertically as planters can also create an excellent greening effect


17 17

Planter boxes for climbers to screen off railingsRailings are screen off by climbers

Higher shrubs to cover the pipe on parapet

wall



Railings and parapet walls can be a great elements for vertical greening

Source: Munsang College Primary School

18 18

All pipes and utilities are exposed as eyesores

Plants can screen off eyesores to enhance to amenity value


Climber on parapet wall

Shrubs to cover utilities and pipes



19 19



• Logo / Graphic on Wall

Logos can also be composed by a small pots plugged in vertical planters

20 20

• Cooling effect with vertical greening as a buffer

– Reduce sun exposure in the evening


21 21

Design Features for Green Roof and Vertical Greening• Small garden design concept

Arrange plant carefully with different heights and layers can create an interesting spaces and enclosure feeling

22 22

• Decks, Pavements, Furniture and Shade area

Wood deck was built as a path and resting area


Source: The Hong Kong Jockey Club Headquarters

Paving and vertical greening on roof garden

23 23

• Decks, Pavements, Furniture and Shade areaDesign Features for Green Roof and Vertical Greening

24 24

• Water feature for cooling, irrigation and amenity



School green roof with water feature can enhance the cooling effect for the building and the biodiversity in the roof.

Source: Architectural Services Department

25 25

• Recycle material



Plastic bottles and aluminum cans be skillfully used in the green roof garden as a planting materials

Reuse wasted banners to become the waterproof membrane


26 26

• Modular System


- movable planter boxes (modular system) -more flexibility

- easy to install and flexible to adjust and rearrange as needed

27 27

• Play, Learn, Eat

Collecting food waste

Burial food waste

Food waste decomposing

Organic fertilizers


Source: Ng Yuk Secondary Shcool

28 28

• Solar energy - integration• Experimental Results:

– PV panel shades and reduces surface and soil temperature of green roof

– Green roof cools PV panels and increases its power output

– PV-GRS integration generates 8.3% more electricity than PV alone

– Less evaporation under PV panels



29 29

• Plant selections– fragrance

含笑含笑 Banana Shrub (Banana Shrub (MicheliaMichelia figofigo))

九里香九里香 Orange Jasmine (Orange Jasmine (MurrayaMurraya paniculatapaniculata)) 桂花桂花 KwaiKwai--FahFah((OsmanthusOsmanthus fragransfragrans))

米仔蘭米仔蘭 Mock Lime Mock Lime ((AglaiaAglaia odorataodorata))

Source: Hong Kong Herbarium & www.hktree.com


30 30

• Plant selections– Native plants



龍船花龍船花 Chinese Chinese IxoraIxora ((IxoraIxora chinensischinensis ))假蘋婆假蘋婆 LanceLance--leaved leaved SterculiaSterculia((SterculiaSterculia lanceolatalanceolata))

珊瑚樹珊瑚樹 Sweet Sweet ViburnumViburnum((ViburnumViburnum odoratissimumodoratissimum))

石斑木石斑木 Hong Kong Hawthorn Hong Kong Hawthorn ((RhaphiolepisRhaphiolepis indicaindica ))

31 31

Source: http://web.expasy.org/


破布葉破布葉 MicrocosMicrocos ((MicrocosMicrocos nervosanervosa )) 九層塔九層塔 Basil (Basil (OcimumOcimum basilicumbasilicum))

射干射干 BlackBlack--berry Lily berry Lily ((BelamcandaBelamcanda chinensischinensis))

薄荷薄荷 Peppermint Peppermint ((MenthaMentha canadensiscanadensis ))


• Plant selections– Herbs / Chinese medicinal plants

32 32


忍冬忍冬 HoneysuckleHoneysuckle ((LoniceraLonicera japonica)japonica)

大花老鴉嘴大花老鴉嘴 LargeLarge--flowered flowered ThunbergiaThunbergia((ThunbergiaThunbergia grandifloragrandiflora ))

異葉爬山虎異葉爬山虎 DiverseDiverse--leaved Creeperleaved Creeper((ParthenocissusParthenocissus dalzieliidalzielii ))

炮仗花炮仗花 FireFire--cracker Vinecracker Vine((PyrostegiaPyrostegia venustavenusta ))

• Plant selections– Climbers

33 33

Why Green Roof / Vertical Greening?

Thank you!Please visit DEVB’s Greening website for more information: http://www.greening.gov.hk

design tips for green roofs and vertical greening in schools...source: hong kong herbarium & ....

Documents