Green Rooftop for Odegaard Library
A proposal prepared by
Team Groof
Devin Ford
Scott Jenks
Heidi Yee
Qicheng Zhao
for
Phyllis Wise
HCDE 333
University of Washington
April 28, 2011
1
Team Groof
University of Washington
Seattle, WA 98195
April 28, 2011
Phyllis Wise
HCDE 333
University of Washington
Seattle, WA 98195
Dear Phyllis Wise:
As you may know, the University of Washington has recently suffered from enormous
budget cuts, which means less funding for student resources. Odegaard is one of the major
student resources that could be directly affected by the budge cuts. We believe if we can save
money on Odegaard’s utility cost, we can keep Odegaard open at its normal hours without
worrying about lost funding.
Odegaard is the only library on campus open 24 hours on weekdays. In fact, it is open
136 hours out of 168 hours in a week. With such a demand to keep the library open, a large
amount of money is used to keep it open. Our proposal is using an extensive green rooftop to
decrease Odegaard’s energy consumption. Green rooftops are layers of insulation, including a
top layer of vegetation. These layers keep the building insulated. Green rooftops also reduce
energy cost and are also good for the environment. We believe we can cut Odegaard’s energy
cost by 5 - 25% after implementing the green rooftops. This has been a proven technique locally
and in many other countries, including Japan and Germany.
If approved, we would like to start the project as soon as possible. If the project is
approved by May 1st, we estimate we will finish by August 12th, 2012. By implementing the
green rooftop, we will be able to reduce Odegaard’s energy cost, and also keep it running at its
normal schedule.
Sincerely,
Team Groof
Devin Ford
Scott Jenks
Heidi Yee
Qicheng Zhao
2
Table of Contents
Executive Summary ........................................................................................................................ 5
Introduction ..................................................................................................................................... 6
Types of Green Roofs ..................................................................................................................... 7
Extensive Green Roof ..................................................................................................................... 8
Installation................................................................................................................................................. 8
Maintenance ............................................................................................................................................ 12
Benefits ................................................................................................................................................... 13
Statement of Work ........................................................................................................................ 14
Project Timeline ............................................................................................................................ 15
Personnel Information ............................................................................................................................. 16
Cost Information ........................................................................................................................... 17
Conclusion .................................................................................................................................... 18
Appendix ....................................................................................................................................... 19
References ..................................................................................................................................... 20
3
ILLUSTRATIONS
TABLES
Table 1. Comparison between extensive and intensive green roofs ............................................................. 7
Table 2. Cost for an extensive green rooftop on Odegaard Library ............................................................ 17
Table A1. Specific start and end dates for the projected timeline ...…….……………………………………………..….20
FIGURES
Figure 1. Composition of an extensive green roof system ............................................................................ 8
Figure 2. Installation of waterproof membrane ............................................................................................ 9
Figure 3. Installation of roof barrier.............................................................................................................. 9
Figure 4. Installation of drainage layer ....................................................................................................... 10
Figure 5. Installation of filter fabric ............................................................................................................ 10
Figure 6. Installation of growing medium .................................................................................................. 10
Figure 7. Components of drip irrigation system ......................................................................................... 11
Figure 8. Adding appropriate plants ........................................................................................................... 11
Figure 9. A projected timeline for placing an extensive green rooftop on Odegaard Library .................... 15
4
Executive Summary
Recently the University of Washington has suffered major budget cuts. These budget cuts
mean less funding for student activities and resources, including funding for student libraries
such as Odegaard. Due to Odegaard being open 136 hours out of 168 hours in a week, the cost of
keeping it open is expensive. Therefore, in order to keep Odegaard running at its normal hours
with the recent budget cuts, a sustainable solution is installing an extensive green rooftop on the
top of the building.
An extensive green rooftop is having layers of different insulation, including green
vegation, installed into a rooftop. The benefits include natural installation, reduction of green
house gases, and conservation of energy. This idea has been implemented in many places around
the world. In fact, the local Ballard library is one of the many places that have already installed a
green rooftop to their building. Other places such as Japan and Germany have also approved the
use of green rooftops. Japan requires that more than 20% of new construction to install green
rooftops.
There are many more benefits of green rooftops. Green rooftops will keep Odegaard
warm in the fall and winter, but cool during the spring and summer. As well, with a reduction in
cost, Odegaard will require less money to operate and would be able to stay open at its normal
hours. Green rooftops are also a sustainable way to help reduce green house gases and is good
for the environment.
5
Introduction
The University of Washington is currently seeking a solution to help make the campus more
sustainable. With increasing demand for more study hours, Odegaard Library has become one of
the main energy consumers on the Seattle campus. In order to save energy and reduce costs, a
viable solution to this problem is implementing an extensive green rooftop. An extensive green
rooftop is an addition to the existing roof which consists of a layer of vegetation. As students of
the University of Washington, we have developed this proposal to convey the potential benefits
and costs associated with installing an extensive green rooftop on Odegaard Library.
With energy costs increasing, a sustainable change is necessary for Odegaard Library. This
particular library is open 136 out of 168 hours a week and consumes a significant amount of
energy to facilitate the needs of students. In order to decrease the rising costs associated with this
high energy consumption, it is our proposal that an extensive green rooftop should be installed
immediately. The scope of this proposal encompasses all of the basic information needed to
understand what an extensive green rooftop is and how it can be beneficial to this campus. Also
included within this proposal is a statement of work detailing all of the steps needed to install
this rooftop, a projected timeline of completion, team background information to show
competency, and an in depth cost analysis. All of these subjects will reveal that an extensive
green rooftop is cost effective and necessary for a more sustainable future here at the University
of Washington.
6
Types of Green Roofs
There are two general types of green roofs: extensive and intensive. Table 1 below shows a
comparison between the two roof types. Intensive green roofs are more complex than extensive
ones. Planting media for intensive green roofs are a foot deep at minimum and weighs from 80 to
120 pounds per square foot. Intensive green roofs are commonly referred to as “garden roofs”
which can exhibit many different kinds of plants. Landscaping can be designed on this kind of
roof. Intensive green roofs are normally applied on roofs which are often seen or visited by
people, such as subterranean parking garage. Intensive green roofs contain a great value in city
landscaping. They can be anything from a public garden to an entire park.
However, extensive green roofs are generally lower in weight, less in cost and require less plant
maintenance compared to intensive green roofs. That is why we chose extensive green roofs for
our Odegaard Library project. Because of the thin soil layer, this type of roof can only support
plants that are tolerant of high heat, drought, wind and frost, such as grass, wildflowers and
moss. Extensive green roofs cannot support a lot of plant types and cannot support landscaping
design. Despite these limitations, an extensive green roof is still appropriate because Odegaard’s
roof is inaccessible to the public anyway.
Table 1. Comparison between extensive and intensive green roofs
Extensive Green Roofs









Intensive Green Roofs
Low-Profile/ Eco-roofs
Low growth media 1” - 6”
Lightweight: 12-50 lbs/sf
Low growing plants: Alpine types,
succulents, herbs, some grasses and
mosses
Usually non-accessible
Slopes up to 30 degree and higher
Less expensive: $12-25/ft2
Low water requirements
Low maintenance
7




High-Profile/ Roof Gardens
> 6” - 15” and deeper
Heavier weights: 50lbs/sf
Huge variety of plant selection,
depending on loads, design & budget





Designed for human recreation
Relatively flat
More expensive: $25 - $40/ft2
Irrigation usually necessary
Higher maintenance
Extensive Green Roof
Extensive green roofs consist of multiple layers, vegetation, soil, filter etc., in order to provide a
growing surface and drainage of excess water on top of the roof. Figure 1 below shows the
composition of an extensive green roof system.
Figure 1. Composition of an extensive green roof system
Installation
The installation of a green roof must meet the German FLL standards which is the
onlyinternationally recognized building standards for green roofs currently. It is imperative that
any storm water that is not absorbed by the roof is drained properly.
8
To gain a better understanding of the installation process, the procedure has been broken down
into steps illustrating a typical installation of a green roof. These steps follow the German FLL
standards to ensure the quality and safety of Odegaard Green Roof Project. All of these steps can
be seen below and are accompanied by pictures under the labels of Figure 2 through Figure 8.
Step 1:
We start with a waterproof membrane. This
step is essential. Most roofs fail because of
water damage. Today there are several
waterproof options from asphalt, to sheeting
to membranes that go on as a liquid.
Figure 2. Installation of waterproof membrane
Step 2:
Add a root barrier. If you use an organic
water-proof barrier such as asphalt, you
should install an additional layer so that
plants would not work their roots through it
while for nutrients. Concrete is one possible
choice. Another is cellular glass, which has
the additional benefit of acting as a layer of
insulation.
Figure 3. Installation of roof barrier
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Step3:
Put in a drainage layer. A drainage layer is
essential to carry away excess water to
gutters so that it can be carried away from
the roof. Typical drainage layers are made of
gravel and pumice. The drainage capacity of
your material has to increase closer to the
gutters and roof drains.
Figure 4. Installation of drainage layer
Step4:
Add a filter fabric. The fabric has to be
porous enough to allow water to flow down
into the drainage area while holding the soil
or growing medium in place. Roots will
penetrate this layer. Typical materials are
polyester or polypropylene. Since polyester
materials are much easier to care for than
polypropylene, we will use polyster for this
project.
Figure 5. Installation of filter fabric
Step5:
Put in a growing medium. Local soil can be
used but runs the risk of introducing weed or
pathogens. Most green roofs will use a mix of
mostly inorganic components like crushed
clay or sand with cleaned top soil and humus
to supply plant nutrients. Many experts
recommend a soil depth of at least three
inches. Therefore, our project demands 4
inches of local soil as our growing medium.
Figure 6. Installation of growing medium
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Step6:
Install drip irrigation. Drip irrigation will
apply water to where it is needed to the roots
of the plants. It's more efficient than taking a
hose to your roof, using less water, which
also means less weight on your roof. Drip
irrigation is an easy way to supply fertilizer to
your plants to get them started. Ultimately if
the appropriate plants are chosen for the
climate, irrigation system can be turned off.
Figure 7. Components of drip irrigation system
Step 7:
Add plants. Choose the appropriate plants for
the local environment. Factors to consider
involve tolerance to sun, frost, heat and
drought and wind. To minimize maintenance,
trees and bushes can be avoided, because
even small trees need a soil depth of a couple
of feet. Load stress has to be considered,
because winds will apply greater pressure to a
Figure 8. Adding appropriate plants
tree compared to grass or flowers.
This completes all of the steps required for the installation of an extensive green rooftop. If
possible, we will top with a wind blanket. This is a biodegradable mesh like jute that will limit
wind erosion while your plants are establishing themselves.
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Maintenance
An extensive green roof will generally only require two maintenance visits every year. The
frequency and level of maintenance of the green roof is down to the discretion of the
client/building owner and the plant appearance they wish to maintain. After the first one or two
years, when the roof is well established, less maintenance will be needed after that.
We recommend two visits per year carried out by our approved contractor to ensure the
guarantee of function. Ideally, these visits would be in spring and autumn.
The maintenance regime would include:

Removal of debris and dead vegetation from the roof surface, drainage outlets, guttering
and washed pebbles, etc.

Sowing of additional sprouts to repair patches of poor growth

Application of slow release, low nitrogen fertilizer

Review inspection chambers and ensure that water outlets are all free draining

Clear and clean all perimeter and detailing surrounds

In severe drought, it is recommended that the plants receive a small amount of irrigation,
though this is largely unnecessary in the Seattle climate
The team who installed the roof should carry out any maintenance.Access to the roof will be
required in order to carry out routine annual maintenance. As with all roofing projects, Green
roof installations must comply with relevant Health and Safety requirements. Under current
legislation, a fall arrest system, safety harness attachments or man safe systems should be used to
ensure safety during installation and to allow for routine maintenance.
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Benefits
There are many benefits associated with the implementation of an extensive green roof. The first
of these benefits are the ecological benefits. An extensive green roof cools and humidifies the
surrounding air, which ultimately creates a beneficial microclimate. Also, it creates a natural
habitat for animals and plants that aid the cause in reducing dust and smog levels within the
surrounding air. These two benefits ought to be welcomed in a university environment that
demands a more advanced ecological surrounding.
Another category of benefits to be understood are technical benefits. The first, and perhaps most
important technical benefit, is the addition of thermal resistance that accompanies an extensive
green roof. This allows for better temperature maintenance within Odegaard Library and will
result in reduced heating and cooling costs. Lawrence Berkeley National Lab researchers
performed a study which determined that extensive green roofs can save 15 to 25% of total
energy costs within a building (asla.org, 2010). Along with thermal resistance, another technical
benefit is storm water retention. An extensive green roof has been proven to reduce storm water
runoff by 50 to 90%, which can be very important in Seattle since rain is so common (alsa.org,
2010). This benefit can also be considered an ecological benefit because it reduces storm water
contamination.
The final category of benefits concerns owner benefits. One of these benefits is the fact that
green roofs have been proven to increase the life expectancy of a roof to up to twice as long of
that seen from a conventional roof. It also requires less maintenance, which saves a great deal of
time and money. Unfortunately, there are no current building incentives for using green roofs in
Seattle, but that may change in the near future with the increasing international popularity of
green roofs.
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Statement of Work
With approval of this proposal, the first step towards installing the extensive green roof is
planning. Planning should begin immediately after approval of the proposal. This type of project
requires professionals from many different fields to ensure success and high quality. Some of the
personnel that ought to be contacted are landscape architects, civil engineers, structural
engineers, and roofing consultants. This planning stage will provide a more accurate evaluation
of the costs and material needed for this specific rooftop. Once a plan of action has been decided
upon, the next step required is to obtain grants and mandatory permits from the Department of
Construction and Permits. With the permits obtained, the next step would be to research
installation companies. Examples of some green roof designer and installation companies that
are located nationwide are American Hydrotech Inc, Sarnafil Inc, and Soprema Inc.
Once the designer and installation company has been chosen, the next steps needed are to
determine a means of irrigation and to install the green rooftop. Once the installation is complete,
certain garden materials will need to be acquired such as growing mediums, plants, fertilizers,
pavers, and substrate containers. It is at this point that the green rooftop must be subjected to
regular maintenance. For the particular green rooftop that we have recommended, an extensive
green rooftop, regular watering is only required for the first six to twelve months. Following this
time period, little maintenance is required. To gain a better understanding of the allotted time
that each of these steps will take, please see the projected timeline. It is the intentions of this
group to have the first stages of work begin by May 1st, 2011 provided that approval of this
proposal can be obtained.
14
Project Timeline
Seen below in Figure 9 is an approximate project timeline for the preparation and installation of an
extensive green rooftop on Odegaard Library. The estimated start date is May 1st 2011 and the end date is
October 29th 2012. Note that the maintenance goes on for 6 months after the end of the installation but
will take very minimal work beyond that point.
5/1/2011
8/9/2011
11/17/2011
2/25/2012
6/4/2012
9/12/2012
12/21/2012
Approve Project/Obtain Grant
Consult Experts
Obtain Permits
Select Instalation Companies
Install Irrigation Route
Obtain Necessary Materials
Install Green Roof Top
Maintenance
Figure 9. A projected timeline for placing an extensive green rooftop on Odegaard Library
For a further outline of the specific dates involved in this process, refer to Table A1 in the Appendix.
15
Personnel Information
Heidi
Heidi is a senior student enrolled in the Industrial Engineering program at the University of
Washington. She had previous experience at Boeing, where she had to research and write a
formal proposal for the Boeing Everett Delivery Center.
Qicheng Zhao
Qicheng is a senior student in Industrial Engineering. She has preivous experience with budget
calculation and project timeline management. Her material science background helps select
green roof materials for this project.
Scott Jenks
Scott is a junior at the University of Washington and is enrolled in the school of Mechanical
Engineering. He has previous roofing supply experience and is knowledgeable in all of the
advantages and disadvantages of different roofing materials. His education and life skills allow
him to be an asset to this project to install an extensive green roof.
Devin Ford
Devin Ford is currently a junior in the school of Mechanical Engineering at the University of
Washington. His previous experience with irrigation projects gives him the general knowledge
needed for this project. His previous job managing interns at EA has allowed him to gain
knowledge in the importance of deadlines and cost benefit analysis.
16
Cost Information
To better understand the costs associated with an extensive green rooftop, it is first important to
see a general range of costs associated. These general cost values were then used to determine
approximate cost values for Odegaard Library. The general and approximated Odegaard cost
values have been tabulated and placed below in Table 2.
Table 2. Cost for an extensive green rooftop on Odegaard Library
Component
General Cost
Odegaard Cost
Consultations
3.5% (of total roofing cost)
$11,357
Drainage
$3.00 / square foot
$66,000
Filtering
$1.50 / square foot
$33,000
Pavers
$1.00 / square foot
$22,000
Growing Medium
$1.00 / square foot
$22,000
Plants
$2.00 / square foot
$44,000
Installation & Labor
$4.00 / square foot
$88,000
Irrigation System
$2.00 / square foot
$44,000
Maintenance
$0.25 / square foot
$5,500
Total Cost
$335,858
It is important to note that the rooftop of Odegaard Library is approximately 22,000 square feet.
This approximate value was multiplied by the rate of each section to determine the relevant costs
for Odegaard.Also, note that maintenance on an extensive green rooftop is only required for the
first six to twelve months, which would lead to reduced costs after this time.
With this approximation of the costs, it has been estimated that the extensive green rooftop on
Odegaard Library will return a breakeven point around 15 years. This is based on the knowledge
that on average, extensive green rooftops reduce energy consumption up to 25%. The breakeven
point was also determined by including the fact that a green rooftop has over twice the lifespan
of a conventional roof and has a much lower returned maintenance cost.
17
Conclusion
In conclusion, installation of an extensive green rooftop is an opportunity for the University of
Washington to become more sustainable and save money. The benefits from installing an
extensive green roof are reduced energy costs, an increase in the lifespan of the roof, temperature
regulation, and building insulation. Some environmental benefits of an extensive green roof are
storm water retention, water filtration, reduction of greenhouse gasses, and improved air quality.
All of these benefits would accompany a projected cost of $335,858 and is projected to reach the
breakeven point in 15 years with the money saved through lower energy costs.
With acceptance of the proposal, work could begin immediately. The main capillaries of work
required are the planning process, the installation phase, and the maintenance upkeep. The
planning process includes obtaining grants and permits, consulting experts, and selecting the
installation company. With this completed, the roof could be installed and maintenance could
begin. If this project were to be started by May 1st, 2011, the roof is projected to be completely
finished by October 29th, 2012. The background of each individual in this team shows the
promise and competency that will follow this proposal through to completion. Every individual
within this team is very dedicated to seeing this project be successfully carried out and see
Odegaard Library acquire a more sustainable environment.
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Appendix
Table A1. Specific start and end dates for the processes shown in the projected timeline
Tasks
Start Date
Duration (days)
End Date
Approve Project/Obtain Grant
5/1/2011
200
11/17/2011
Consult Experts
11/17/2011
31
12/18/2011
Obtain Permits
12/18/2011
7
12/25/2011
Select Instalation Companies
12/18/2011
14
1/1/2012
Install Irrigation Route
1/1/2012
30
1/31/2012
Obtain Necessary Materials
1/1/2012
7
1/8/2012
Install Green Roof Top
1/31/2012
92
5/2/2012
Maintenance
5/2/2012
180
10/29/2012
19
References
American Society of Landscape Architects - Sustainable Residential Design: Increasing Energy
Efficiency. (n.d.). American Society of Landscape Architects - Home. Retrieved May 02,
2011, from http://www.asla.org/ContentDetail.aspx?id=24980
Dinsdale, S., Pearen, B., & Wilson, C. (2006). Feasibility Study for Green Roof Application on.
p. 1-58.
GLWI | Green Roof | Installation. (n.d.). Great Lakes WATER Institute. Retrieved May 02, 2011,
from http://www.glwi.freshwater.uwm.edu/research/genomics/ecoli/greenroof/
roofinstall.php
MyDailyNews.com. (2009, September 20). Retrieved May 2, 2011, from
http://www.nydailynews.com/img/2009/09/20/450x323-alg_green_roof.jpg
T. Caine (2010, October 4). One Roof, Two Roofs, Green Roof, Blue Roof. Intercon. Retrieved May
2, 2011, from http://progressivetimes.files.wordpress.com/2010/10/green-roof-detail.jpg
The Scott Arboretum's Garden Seeds. Retrieved May 1, 2011, from
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The Scott Arboretum's Garden Seeds. Retrieved May 1, 2011, from
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