Seminar in-chargeDr. T. Manjunatha Rao, Principal Scientist, IIHR, Hessaraghatta, Bengluru

SpeakerCh. Girija Kumari, ID: 10468

Ph. D. ScholarDept. of Floriculture and Landscaping

IARI-IIHR, Bengluru, Karnataka

Roof top garden / Green roof

“A green roof or living roof is a roof of a building that is partiallyor completely covered with vegetation and a growing medium,planted over a water proofing membrane’’

Janakiram et al., 2014

A BRIEF HISTORY OF ROOF GARDENS

The earliest known record of roof gardens are the ancientziggurats of Mesopotamia

These massive stone structures were built between 4,000 -600 BC

A series of stairs along the outside perimeter of thestepped pyramid provided access to the various tiers of thestructure

Shimmin, 2012

A ziggurat which closely resembles that

in Nanna built by the first king of the Ur

Dynasty, Ur Nammu. The tiers of trees

provided shade from the blazing

Babylonian sun.

THE HANGING GARDENS OF BABYLON

King Nebuchadnezzar, a famous general in his time, built the Hanging gardens for his wife during 8th – 6th century BC

The ziggurat had a 400 ft2 base, with landscaped terraces eventually the grand roof garden at the top, 75 feet above the ground

Artist’s rendition of the Hanging

Gardens of Babylon, one of the

Seven Wonders of the Ancient World

The terraced layout explains thephrase "hanging garden,” where thevegetation hung over the walls tothe level below

The weight of the garden wassupported by a series of arcadeswhose walls were sixteen feet thick

•The garden was watered through a complex irrigation system fed by“machines” hidden from public view that pumped water from the riverEuphrates eighty feet below to the top of the roof garden

• The structure supported a forest of trees, exotic plants, wildlife andperpetually green grass

•Some trees grew to be as tall as 50 feet

Archimedes screw

THE HANGING GARDENS OF BABYLON

A garden is always known to provide a place to enjoy and relaxbut in cities space is a limiting factor

Boom in real estate business, sky rise corporate buildings,western look out malls, star hotels, garden suburbs have pavedthe way to bring new landscape solutions in recent times

Mushrooming roof top garden in a gargantuan mannermatching the modern life trend is one such new initiation

Need for Roof gardening

Jawaharlal & Kumar, 2013

Reduce the “urban heat island effect”

Reduce amount of greenhouse gas

Reduce and clean storm water runoff

Reduce energy consumption

Increase the beauty of cities

Benefits of Roof Gardening

Green roofs can be used to alleviate urban-heat island effect

Wong, 2006

Thermal properties of green roof

a. Evapo-transpiration

b. Shading by plants

c. Thermal insulation

d. Thermal mass storage

Hui, 2009

Basic components of a green roof system

Types of roof gardens

Extensive roof garden

Intensive roof garden

EXTENSIVE

INTENSIVE

2oth century- new era of roof gardens

Extensive roof gardens have origin in 20th century in Germany. This trend was

in Germany since 1960s

Berlin has between 5-30% of roof space greened in different parts of the city

In London, about 100,000 m² green roofs were installed in 2008

Shanghai, also installed a similar amount in 2008

In France, approximately 1 million m2 of roofs are greened per annum

Similarly, approximately the same area was covered in 2009 in North America

Germany adds about 11 million m2 of green roofs each year

www.greenroof.org

Rooftop gardening is an attractive and energy-saving alternative to a conventional rooftop

Daley,2007

Integration of green roof and solar photovoltaic systems

Case study - 1

Hui and Chan, 2011

Paper submitted to Joint Symposium 2011: Integrated Building Design in the New Era of Sustainability

Objectives of the study

To study the benefits of integrating the green roof andsolar photo voltaic systems

Assessing the important factors affecting the interactionsbetween the two systems

To promote sustainable building design

Hui and Chan , 2011

Four simulation models for the investigation of energy performance

ENERGY SIMULATION ANALYSIS

Hui and Chan, 2011

FIELD MEASUREMENTS

Hui and Chan, 2011

Annual Energy Consumption of lighting and space conditioning

Hui and Chan, 2011

Monthly power generation of stand-alone PV and green roof integrated PV systems

Hui and Chan, 2011

Hui and Chan, 2011

4-50 C

PV power output on bare roof and integrated system

Hui and Chan, 2011

4.3 %

more

Summary

Energy consumption for airconditioning of the integratedsystem is less

PV system on integratedapproach generates 8.3% moreelectricity than the stand-aloneoption

Extent of the benefits dependson the system design and how todetermine the optimumarrangement for a particularbuilding site lower than thestand-alone system

VERTICAL

GARDENS

This concept of gardening was developed in Switzerland

Patrick blanc

VERTICAL GARDEN

Evolution of vertical gardens

What is Living Wall/Biowall ?

•Self sufficient vertical gardens attached to interior or exterior of a building

Living wall

Green Facade

Green wall

Green facade

Green facades use climbing plants to cover walls or structures

These are much less complex than a green walls

Plants are rooted in soil or containers, growingupwards or cascading down on a structure

To maintain their position, develop growth andsurvive through seasonal exposures, good structure isimportant

Green facades are easily scalable and rely on theadaptable characteristics of a broad range of plantspecies

Green facades reduce wall surface temperatures by as much as 5-90 C

compared with exposed wall surfaces

www.verticalgardenpatrickblanc.com

Types of Green facades

Two types of structural green facades systems

1. Two dimensional system 2. Three dimensional system

Green WallsGreen walls are self sufficientvertical gardens that are attachedto the exterior or interior of abuilding

They differ from green facades(e.g. ivy walls) in that the plantsroot in a structural support whichis fastened to the wall itself

The plants receive water andnutrients within the verticalsupport instead from the ground

1_Trellis: support panel2_Cellular polypropylene panel:Water proofing thermal Insulator roots proof with stapled shelves3_Fertigation supply line4_Growth medium: coconut coir_3cm height5_Green mat: ground cover plants6_Metalic mesh: support substrate and plants

How Does It work?

DrainIrrigation

Living wall system

The best protection against humidity was obtained with use elastomer materials

The modular systems are the best solution possible for solving this type of problem

Steel structures can be used also, but this type of structures is expensive

Problems with vertical walls

Humidity

Plant assortment

Pollutants

Benzene Xylene Formaldehyde Toluene Carbon monoxide

Chlorophytum *** ** *** *** ***

Dracaena ** *** ** *** ***

Hedera helix * * *** *

Nephrolepisexaltata

*** ***

Phalaenopsis *

Scindapsusaureus

*** * *** ***

Spathiphyllum ** ** **

Plant suitable for vertical gardens for improving indoor air quality

Energy Savings Building Protection LEED® Credits

Indoor Air Quality Property ValueAcoustics

SUSTAINABILITY

Benefits of Vertical gardens

Aesthetics

Utilizing a vertical garden to reduce indoor carbon dioxide in an indoor environment

Yarn et al., 2013

Wulfenia Jouranl

Case Study-2

To Investigate the effect of the photosynthesis of the plants in a vertical garden on the indoor CO2 purification

Objective of the study

Dieffenbachia 'Camilla‘

Pachira aquatica

Chlorophytum comosum

Spathiphyllum kochii

Materials and methods

Four indoor plants The individual plant, small fan and CO2

sensor were placed in a closed and

transparent acrylic case sized 0.5m in

length, 0.5m in width and 1m in height

Yarn et al., 2013

The CO2 absorption rate experiment of individual tested plant

Yarn et al., 2013

Change in CO2 concentration of four different of plants with in two days

Chlorophytum comosumDieffenbachia

Spathiphyllum kochii

Pachira aquatica

night nightday

Yarn et al., 2013

plant cultivation area

human activity area

3 cyclic fan

3 return air inlet

Three-dimensional geometric model of the indoor environmental control room

split-type air conditioner

Yarn et al., 2013

Yarn et al., 2013

Indoor environmental control room in experiment

Variation of CO2 concentrations with time for Spathiphyllum kochii at different initial CO2 background concentrations

Finally a stable value of will be reached (400 ppm)

Yarn et al., 2013

Instant absorption rates under different CO2 concentration levels

Yarn et al., 2013

Comparison of concentration level of CO2 for different ACH with or without plants

Yarn et al., 2013

The results showed that, after 150minutes, 13% of CO2 generating from thehuman breathing can be absorbed by the240 plants

Summary

The experimental results proved thatindoor planting can be applied to purifyindoor air

However , the effect in not severe unless agreat amount of plants was cultivated in thevertical garden

Vertical gardens can also be used to reducethe air change rate of the ventilation systemin a living room and are beneficial to theenergy saving of the ventilation system

CONCLUSIONS

Green roofs and verticalgardens can help reduce some ofthe impact that urbanisationimposes on the environment andour quality of life

But the hour of the mark is tohave cost effective and sustainableroof and vertical garden using thelatest innovations

In general roof top and verticalgardens are promising methodsto bring back greenery pushedaway from urban areas

Landscape artist Marc Graney's system Phyto-kinetic Bus with green roof

Girona, Spain

T

H

A

N

K

Y

O

U