Presentation at the IGRA congres Hamburg May 14th 2013 about first research results on Green Roof Specifications and Uniform methods for calculations and measuring at Rotterdam University of Applied Science

1. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Technical and Ecological
Characteristics of Green Roofs
Workshop 1
Hamburg 14 May 2013
Dr. Christoph Maria Ravesloot M.Sc.Eng.M.STS.
Professor Sustainable Innovation Design and Construction Processes
Rotterdam University of Applied Science

2. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Extensive Green Covered Roofs
The absence of standardized assessment
procedures and methods of calculation for
the technical and eco- logical characteristics
of Green Roofs is hindering the development
of the Green Roof market in the Netherlands

3. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Faster more large areas
of green roofs
Privat clients
Public authorities
• Verification and validation specifications
• Measure and calculate
• Specifications can not be compared
• Business cases can not be compared
• Public authorities can hardly estimate impact
• Public authorities have difficulties developing
effective governance models and cost estimations
BEGROEIDEDAKENNA2010Teeuw|Ravesloot
Dakbegroeiing in de stad levert een maatschappelijk voordeel in
termen van leefmilieu en waterbuffering, mits toegepast op de
juiste plek en op grotere schaal.
Dit potentieel kan alleen benut worden als de verschillende partijen
zich goed organiseren in de samenwerking, en als de kosten en
baten zichtbaar gemaakt kunnen worden: voor de eigenaar, de
beheerder en de gebruiker van het gebouw, als ook voor planners
en stedebouwkundigen.
Begroeide daken na 2010 belicht deze grotere schaal en bena-
dert de materie hiermee vanuit een nieuw perspectief. Teeuw en
Ravesloot publiceren al sinds 1991 op het onderwerp van begroeide
daken en geven met deze publicatie verder richting aan de praktijk
en toepasbaarheid van dakbegroeiing in Nederland.
Begroeide Daken na 2010
Afstemming van techniek, organisatie & maatschappelijk belang
Peter G. Teeuw | Christoph Maria Ravesloot
Begroeide daken na 2010
Afstemming van techniek, organisatie & maatschappelijk belang
Peter G. Teeuw | Christoph Maria Ravesloot
Begroeide daken na 2010
Afstemming van techniek, organisatie & maatschappelijk belang
Peter G. Teeuw | Christoph Maria Ravesloot
Techne Press

4. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Research Team
Classification implementation
technical specifications
Dr. Christoph Maria Ravesloot, M.Sc. Eng. M.STS procesmanager
Dr. Carleen Mesters, projectmanager casestudies, Wageningen Arnhem
Wim Verburg, M.Sc.Eng projectmanager casestudies Rotterdam
HEAT: Erik Huang, Pepijn Somers, Marc Delemarre
Mitchel Klaasman, Stephen Abraham Reynolds, Dyiako Shadmanfar
WATER: Tine van Langelaar , Senny Wagemaker
Thomas Mos, Bastiaan van der Horst, Sander Versluis, Jorte Weij
COST BENEFIT ANALYSIS: Yassin Boulghalegh, Tosca van Zijl
CONSTRUCTION: Madina Karim, Geoffrey Quak, Raimon de Jong,
WIND: Jason Koppelle

5. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Classification
Private clients, business
developers and public parties
• Stimulation of innovation, aiming at increasing the
market share of green covered roofs and increasing
competition by:
• alignment of private goals and public goals
• development of uniform classification of technical
specifications
• Tools that accelerate and enhance implementation
of green covered roofs for private parties and
authorities

6. ©2013 dr.drs.ir. Christoph Maria Ravesloot
PLANNING 2012-2013
Euro 750.000,00
50 % private funding public funding
14May2013

7. ©2013 dr.drs.ir. Christoph Maria Ravesloot
14May2013
case studies
Alexandrium 2013 Rotterdam
House of Sports 2013 Utrecht
Office building 2013 Arnhem and Rotterdam
SME SME SME SME SME SME SME SME SME SME

8. ©2013 dr.drs.ir. Christoph Maria Ravesloot
OVERLOOK AND ANALYSIS
WATER AND HEAT
Heat
Senny Wagemaker
Water
Marc Delemarre
Pepijn Somers
Erik C. HuangTine van Langelaar

9. ©2013 dr.drs.ir. Christoph Maria Ravesloot
SYNTHESIS
WATER, HEAT, VALUE, WIND,
CONSTRUCTION AND PV
Heat
Jason
Koppelle
Wind
Thomas Mos
Bastiaan van der Horst
Water
Sander Versluis
Jorte Weij
Tosca van Zijl
Yassin Boulghalegh
Construction
Mitchel
Klaasman
Madina Karim
Geoffrey Quak
Raimon de Jong
Value PV
Dyiako Shadmanfar
Stephen Abraham-Reynolds

10. ©2013 dr.drs.ir. Christoph Maria Ravesloot
EVALUATION
WATER, HEAT, VALUE, WIND,
CONSTRUCTION AND PV
Verification, validation
Knowledge transfer NEN
Business cases water and heat

11. ©2013 dr.drs.ir. Christoph Maria Ravesloot
WATER results
YES WE CAN
• Link water specifications of green covered roofs to
specific calculation models for capacity sewer
systems and capacity water systems per city quarter
• Tolerances in the specifications have to be narrowed
down to get more reliable estimations
• Reliable estimations are necessary for development
of new business models to share cost and benefits
on a larger scale than within circles of public
authorities and within circles of private parties

12. WATER results
Modeling rainwater run off
Peak run off green roof Peak run off black roof Rain
©2013 dr.drs.ir. Christoph Maria Ravesloot
• Influence of green covered roofs on peak run off was 13 %
• Influence of paved private gardens on peak run off was 30 %
Rain Evaporation black roof Evaporation green roof
Rainfall

13. ©2013 dr.drs.ir. Christoph Maria Ravesloot
HEAT results
WE CAN NOT estimate Insulation
WE CAN estimate Cooling
• From literature research is concluded that nor in
winter nor in summer conditions any contribution to
the u-value of green roof construction can be
expected. There are some exceptions that are being
tested in case studies.
• The shading and cooling from evaporation on green
covered roofs can contribute to decrease of cooling
demand under roofs. The calculation however is not
easily executed due to illogical input possibilities in
calculating software

14. ©2013 dr.drs.ir. Christoph Maria Ravesloot
HEAT results
Little estimated extra insulation
Leaf Area Index LAIshort
wave
infra
red
long
wave
infra
red
convec
tion
heat
exchange
heat
loss
through
eva-
poration

15. ©2013 dr.drs.ir. Christoph Maria Ravesloot
HEAT results
Little estimated extra insulation vegetation
air between leafs
wind membrane
substrate
filter membrane
drain membrane
root secure membrane
security membrane
water safe membrane
insulation
construction
indoor space
short wave heat reflection / absorption
from vegetation and substrate
heat flux from conductivity through layers
heat storage in mass of materials
heat from persons and installations
heat from photosynthesis in the vegetation
is not taken into account
long wave heat exchange between
layers, vegetation and substrate, to
atmosphere
heat loss trough evaporation of water
in the substrate and through
vegetation
long wave heat exchange between
layers, vegetation and substrate, to
atmosphere

16. ©2013 dr.drs.ir. Christoph Maria Ravesloot
COOLING results
Sensitivity for cooling from shading
and for cooling from evaporation
• LAI Leaf Area Index seems to be important
• Moisture and water have significant influence
• Plants can give considerable shading

17. ©2013 dr.drs.ir. Christoph Maria Ravesloot
PV results
WE CAN estimate improved yield
WE CAN make a decision model
• PV panels produce more kWh electricity if cooled by
a green covered roof underneath. The yield will
improve between 4 % - 16 %, according to case-
studies around the world.
• A decision support model for designers will be
made, to maximize potential for cooling PV with
green covered roofs.

18. ©2013 dr.drs.ir. Christoph Maria Ravesloot
CONSTRUCTION results
WE CAN find potential capacity
WE CAN make a decision model
• STEEL roofs: big areas for greening like shopping
malls, sport facility building, industrial buildings
• CONCRETE roofs: big ares for greening like
residential ares for housing corporations and like
office buildings
• old norms for construction calculation might have
some residual capacity hidden in safety norms and
inaccuracy of calculating formulas

19. ©2013 dr.drs.ir. Christoph Maria Ravesloot
WIND results
How about wind speed
How about counter weight and form
• At edges on roofs high wind velocity occurs
• Substrate (sand) can start eroding at low velocities
• Vegetation can offer resistance to erosion
• Vegetation and substrate offer weight
• Vegetation offers stability from a flat plate of weight
• Liquidation of pressure is known for tiles and gravel

20. ©2013 dr.drs.ir. Christoph Maria Ravesloot
VALUE results
WE CAN calculate cost benefits
WE make new business models
• Scale of buildings CBA
• Scale of water management systems of city quarters
• Scale out of water management systems, city wide
or even on higher scales

21. ©2013 dr.drs.ir. Christoph Maria Ravesloot
VALUE results
WE calculate social cost benefits
WE support governance models
• deliverable calculation models
• possible implementation in urban planning
• combining technical and ecological characteristics with
municipal support programs
• framework of rain- water fees
• framework of cooling capacity for commercial buildings

22. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Conclusion
We can see the huge amount of
knowledge all over the world
• however, there is little integration of knowledge and
little application in practice, yet
• however, there are strong opinions hindering
innovation and product development
• however, there is still a lot of work to be done, not
necessarily Research, more Development (R&D)
• uniform assessment methods on specification will help
if quick and dirty
• norms can compensate with higher standards

23. ©2013 dr.drs.ir. Christoph Maria Ravesloot
Let’s carry on
All together now
February 2013 Working conference Public-Private business models
@ChristophMaria ChristophMaria@Ravesloot.nl