Green roofs are an integral component of sustainable development in the arid West.
Friday, May 27, 2011
GrowWest Symposium
We are proud to support two great classes. On Wed June 15 Green Roofs for Healthy Cities is offering a Green Roof Maintenance Course and on Friday June 17, The Front Range Sustainable Landscaping Coalition is offering a Green Infrastructure course. Both events are being held at Denver Botanical Gardens. Class registration can be found at Denver Botanical Gardens and Green Roofs for Healthy Cities website
Also added to the day of the symposium are poster sessions from Richard Sutton,MLA Ph. D.,(University of Nebraska-Lincoln) and Reid R. Coffman, MLA, Ph.D.n (University of Oklahoma. Richard will present "The Four-year Ecological Genesis of a Prairie-based Green Roof" and "The Four-year Ecological Genesis of a Prairie-based Green Roof". While Reid will discuss Green Roofs and biodiversity impacts.
See you all there.
Monday, March 21, 2011
Secondary Spaces
Secondary Spaces: Roof Gardens in
Recently my colleague
Husein: I have always had an interest in roof gardens, they give a building much more than heating and cooling efficiency. They provide buildings with these special places were nature can thrive in the middle of a dense urban area. While working on
Karla: When Husein and I collaborated, along with an incredible team, on the roof garden at MCA, the curiosity about roof gardens and green roofs stuck. My interest comes from a landscape perspective rather than urban planning background. I am curious about habitat matrixes and green oases above ground in the urban core of downtown
As a part of our adventure, we came up with eight questions: four from an urban planning perspective and four from a landscape architecture perspective. Here follows the questions and our responses.
1. 1. Private vs. Public or semi public. What defines this? (Control, Maintenance, Access)
From the sites visited we can conclude that there is no public vs. private, it is private vs. private. Historically, cities encourage developers to provide open space for public use and gatherings in exchange for additional floor space. Municipal, state and federally owned public places are usually less controlled then privately owned places. Our taxes maintain our public places, and private landscapes are usually privately maintained. Then there is this third category of which we write about here: privately owned public places. They have a different and strict set of rules for the public accessing these spaces. The owner has a right to limit or restrict access to the area (2009 Nemeth, Schmidt. “The Privatization of Public space: Modeling and Measuring of Publicness”). Historically privately owned exterior spaces provided for “the public”, (defined here perhaps as visitors not owners/taxpayers) gathering were built in exchange for additional floor space.
But wait, it gets more confusing. The first site,
The second site, which we will call the sibling site as it is across the street and connected by an elevated walkway, is open to the public from four sides without any restriction. You can enter at several points along
The third site is on the second level, adjacent to an apartment complex and is only available to those living there. There is no access, except for locked gates, from the street level and the only way to get in is via the central elevators inside the building. This place is definitely private.
2. 2. 2. Why were these green spaces above ground built in the first place? They all seem to come from a similar time period in
As previously noted, we assume that these green spaces were usually built by developers so city governments would allow more floor space to be added to the development. As part of the agreement perhaps, these spaces would be accessible to all people, but the developer would have a right to limit access to the roof garden in certain hours along with a set of rules that would be different from typical public places, such as parks (2009 Nemeth, Schmidt. “The privatization of public space: modeling and measuring of publicness”. The usage at site number is restricted to tenants. The question is if an agreement was reached between the developer and the city, the manifestation being an exterior “public” space, is the developer a breaking their part of the bargain by limiting or eliminating access?
4. How does time affect these spaces? What are the maintenance issues? Who does what and why?
As all of the spaces are privately owned, the maintenance varies from very well maintained, (one place is planted every year with annuals) to barely maintained where the floor tiles are deteriorating and landscape fabric shows through mulch in the raised beds. What we are unable to ascertain is whether the maintenance or lack there of is affecting the structure, i.e. leaks.
5. How do these roof gardens affect or impact urban habitat? What is the size and scope of the landscape installed? What shape is the plant material in?
These secondary landscapes are at least twenty years, and it is interesting to note that not only is the plant material still alive, it is thriving and mature. In three to four inches of soil, Ponderosa pines reach upwards of twenty feet. Deciduous trees, especially Crabapples have calipers ranging from four to six inches or more. In terms of trees, there are mostly ornamentals as well as large shrubs, ornamental grasses, and perennials and groundcovers. Only where annuals are planted, one does not get a sense of being in an established garden. It feels more like an amusement park entrance.
The plant material exists for the most part in raised beds above roof decks except for the turf areas. Plantings range from dense arrangements to solitary trees and scattered shrubs. There is an exception at
Due to the extent and maturity of the plant material present, we can only assume these secondary spaces are urban oases for insect, bird and to some extent, animal life. When we return during the growing season, we will spend some time gauging other living creatures besides humans.
6. 6. How does the design fit into today’s design framework? Are these places for gathering, oases, parks?
These private parks can be categorized as roof gardens with some sort of decking and seating areas. Some have grills, basketball courts, putting green, garbage cans. Plant material occupies raised beds with the exception of the roof garden described in question five. Some of the spaces could be considered green roofs because of the percentage of “green” coverage on the roof. The design intention is perhaps to create exterior amenities or pseudo parks in exchange for more built space. But wouldn’t it be interesting if they were also thinking about sustainable, stormwater, heat island mitigation issues.Another interesting point is that we have this design idea being implemented 20-25 years ago that form these park like urban areas, far different from the rest of downtown
The existence of these roof gardens in this relative small area makes us think of a new theory in urban planning; “Landscape Urbanism”. The most outspoken person behind this theory is Charles Waldheim, currently a professor at Harvard. The idea is that “urbanism is not about arrangement of buildings, street grids, and parks, rather it is about living processes, flows and the importance of respecting ecological infrastructure”… (2010, Neyfakh. “Landscape Urbanists’ Challenging OldSchool ‘New Urbanism’ for future of…”)to create holistic systems or matrixes made of several landscape components like roof gardens or pervious paving…” We think these secondary spaces are such a system comprised of several landscape components, i.e. roof gardens, pervious paving andstorm water drainage systems that affect a larger area of the city beyond the immediate site.
7 7 7. Do the roof gardens address any of our current sustainable directives like storm water filtration or heat island mitigation?
The spaces with larger beds and more extensive coverage must play a role however indeterminate on storm water filtration. The trading out of hardscape for soft along with mature trees definitely help reduce heat island mitigation.
8. . 8. Do the roof gardens begin to form a matrix or patchwork within the urban fabric, intentionally or not?
Without further research, intentionally or not, because of the proximate locations of the all the secondary spaces we discovered, there is without a doubt a matrix of urban landscape ecology within a dense built environment. This is readily apparent from the google earth image. When we walked onto one roof, we could see across the street to another one. It was this process of discovery, like being on the high seas of tall buildings where we found the next island to explore.
Pedestrian connections are available but limited; two neighboring roof gardens are connected by a bridge above the street, but one roof garden is for tenant use only and the second one is open for anybody. There are visible rules to access the first site posted by sign and physical rules manifested by a chain baring entry to the second site.Tuesday, January 18, 2011
2011 Green Roofs for the West Symposium
“GREEN ROOFS: GREEN INFRASTRUCTURE”
AT DENVER BOTANIC GARDENS
Green Roof Conference and Trade Show at the Gardens
The Symposium will feature a full day of in-depth sessions,
Invited speakers from the
Manfred Köhler: In the 1980s, Prof. Köhler saw that green roofs were a chance to integrate more buildings, in particular, residential apartments, into the greenery of the inner city regions of
Angela Loder is completing her doctoral dissertation on health, green cities, the workplace and green roofs. She works with the City of
Mark Simmons is director of the Research and Consulting Program at the
Dusty Gedge has a deep and active love of nature. He is as the current president of the European Federation of Green Roof Associations, which has been instrumental in promoting green roofs throughout
Paul Kephardt, a renowned biologist, restoration ecologist and expert designer of living architectural systems, is sought after for his skill as an innovator and pioneer in the fields of environmental planning and ecological design. Paul has developed his
The Symposium will also highlight the publication of the new “Design Guidelines and Maintenance Manual for Green Roofs in the Semi-Arid and Arid West.” This publication is now available at http://growwest.org/ for free. The guidelines are a collaboration of the
For more information or to register, visit www.botanicgardens.org and click on the “Calendar” link, e-mail registrar@botanicgardens.org or call 720-865-3580.
Monday, November 29, 2010
Green Roof Design Guidelines and Maintenance Manual
1. The basic elements of a green roof
2. The benefits associated with green roofs
3. How to select the type of green roof for your project
4. The important technical issues necessary to address during design, implementation and maintenance
5. Maintenance issues which ensure longevity of the green roof
6. Detailed cost variables for green roofs
7. Examples of green roofs through several local case studies
Now available for free - go to GrowWest.org
Tuesday, May 4, 2010
Sky Trapezium at MCA
And how wonderfully diabolical, the water loving Arisaema entwined with Fritillaria and the completely xeric Paxistima. Sometimes it pays off to just be creative instead of horticulturally practical.
Sunday, February 14, 2010
Green roof press
Thursday, February 4, 2010
NYC Green Roofs
Wednesday, February 3, 2010
Existing Policies
(Information adapted from Green Roofs for Healthy Cities (GRHC)) www.greenroofs.org
Compiled by GrowWest, 2/3/2010
Included City and State Incentive Programs:
1. Portland, OR
2. Chicago, IL
3. New York State
4. Cincinnati, OH,
5. Toronto, ON, Canada
6. Federal Programs
7. Past Trends and Market Forecast
1. Portland, OR
Motivation for Green Roof Action
In Portland, motivation for developing green roofs is concern about water pollution from
combined sewer overflow (CSO), particularly in light of major pollution of the Willamette River.
Green Roof Policy in Portland
Portland promotes green roof development through a number of policies, but requires green roofs only on public buildings. The following summarizes Portland’s efforts:
All new City-owned buildings are required to be built with a green roof that covers at least 70% of the roof. The remaining roof area must be covered with Energy Star rated roofing material. When practical, all roof replacements must also include a green roof. The City has internal green building consultants to assist City buildings in meeting green building policy objectives. Most public green roof projects have been financed by stormwater fees (see below).
The City Zoning Code offers developers floor area bonuses when they implement stipulated options, like a green roof. The bigger the proportion of green roof coverage, the larger the bonus offered. The owner must sign an agreement ensuring proper roof maintenance (although proper long-term maintenance continues to be a concern).
Portland levies a stormwater management charge for commercial, industrial, and institutional rate payers that is based on the amount of impervious area on site ($6.45 USD per 1000 square feet of hard surface per month). There is an initiative under consideration to reduce charges by 35% for owners who install green roofs with coverage of at least 70%. Residences are charged for stormwater management at a flat rate.
In the Central City District, developments must comply with architectural design guidelines, and are subject to a general design review process prior to approval. A green roof in a design is considered an asset and will assist the proposal in being approved.
Portland provides education and outreach on green roof development, by providing technical assistance to building owners and guided tours of green roofs. It also monitors green roofs.
Portland has funded green roof demonstration exhibits and test sites.
Green roofs are formally recognized as a Best Management Practice in the City’s stormwater manual.
A citizens’ group called “Ecoroofs Everywhere” promotes green roof development for lower income areas. It creates affordable demonstration projects, secures grants for small-scale developments, and negotiates lower prices with vendors.
As of December 2009 there are over 187 ecoroofs covering 9.7 acres (423,000 sq ft).
2. Chicago, Illinois
Motivation for Green Roofs Action
In Chicago, motivation for developing green roofs is concern about the urban heat island
(UHI) effect, air quality and its effects on public health, and aesthetics. The Mayor has
been a strong advocate of green roof development.
Green Roof Policy in Chicago
Chicago has a variety of policies and programs that encourage green roof development.
Specifically:
The 2001 Regulation called the Energy Conservation Code requires that all new and retrofit roofs should meet minimum standards for solar reflection (0.25 reflectance).Chicago’s Bureau of the Environment deemed that green roofs are an acceptable way to lower roof reflectivity, mitigate UHI and improve air quality.
A “Building Green/Green Roof” policy applies to construction projects that receive public assistance or certain projects that are subject to review by the Department of Planning and Development. Through this policy, the City of Chicago grants a density bonus option to developers whose buildings have a minimum vegetative coverage on the roof of 50% or 2000 sq. feet (whichever is greater), usually in the form of a green roof.
Chicago has various City-sponsored green roofs, including demonstration sites, test plots, and others. The City has partnered with green roof providers to build and compare test plots that use different kinds of plants and material. It has issued a report on some of its findings.
Chicago has engaged the Chicago Urban Land Institute, a non-profit organization of real estate professionals, in seminars and surveys. This helped to determine which kinds of incentives would encourage green roof development.
Chicago offers a stormwater retention credit for green roofs, but does not levy a
stormwater impact fee.
The City has a website that supports green roof installation, and provides information and technical assistance.
In 2005, Chicago is offering a limited number of $5,000 grants for building small-scale residential or commercial green roofs.
There is currently no requirement for green roofs in the private sector.
As of June 2004, Chicago had more than 80 green roofs over municipal and private buildings in various stages of installation.
As of 2009 there are over 2 million square feet of green roofs in Chicago
3. New York State
Motivation for Green Roof Action
New York State passed bill (A.11226) to encourage green roofs in order to cut energy and reduce sewage overflow. New York City has a ‘Combined Sewage System’- runoff and untreated sewage overwhelm the system and it enter the rivers. New York City is the only city to qualify under the bills provisions.
Green Roof Policy in New York State
Building owners who install a vegetated roof on at least 50% of their roof space are able to apply for a one year property tax credit up to $100,000. sponsored by Assemblyman Ruben Diaz Jr. that passed the state legislature today
The credit would be equal to $4.50 per square-foot of roof area that is planted with vegetation, or approximately 25 percent of the typical costs associated with the materials, labor, installation and design of the green roof.
The City of New York recently released the final rules and an application for applying for the $4.50/s.f. green roof tax abatement
The green roof tax abatement is aligned with Mayor Bloomberg's long-term sustainability plan, PlaNYC, released in April 2007. PlaNYC promotes the use of Best Management Practices (BMPs) to control and capture storm water using distributed and natural infrastructure solutions.
The federal stimulus bill provided $432 million for clean water infrastructure projects in NY State, and required that 20% ($86 million) be set-aside specifically for green stormwater infrastructure — i.e., projects that maintain, restore, or mimic natural systems to infiltrate, evapotranspirate, or recycle stormwater – as well as water or energy efficiency improvements, or other environmentally innovative projects.
In 2008 358,956 sq ft of green roofs were built in New York City.
4. Cincinnati, Ohio
Motivation for Green Roof Action
This incentive was enacted to meet federal requirements to reduce the amount of sewer overflows handled by its sewer district.
Green Roof Policy in Cincinnati
Approved by Cincinnati City Council in September, the program offers low-interest loans for the construction of vegetated roofs. Starting in early 2009, an estimated $5 million per year in below-market-rate loans from the U.S. Environmental Protection Agency's Clean Water State Revolving Fund will be available to cover the incremental cost of adding a green roof to a new or existing building.
· The program, administered by the Metropolitan Sewer District of Greater Cincinnati, is the first of its kind in the state, according to the Ohio EPA.
· It will help the city meet federal requirements that it reduce the amount of sewer overflows handled by its sewer district, said City Councilman Chris Bortz, who led the effort to enact the program.
5. Toronto, ON, Canada
Motivation for Green Roof Action:
The benefits were determined as initial cost saving related to capital costs or an amount of annually recurring cost savings.
Category of benefit Initial cost saving Annual cost saving
Stormwater $118,000,000
Combined Sewer Overflow (CSO) $46,600,000 $750,000
Air Quality $2,500,000
Building Energy $68,700,000 $21,560,000
Urban Heat Island $79,800,000 $12,320,000
Total $313,100,000 $37,130,000
From: Report on the Environmental Benefits and Costs of Green Roof Technology for the City of Toronto. http://www.toronto.ca/greenroofs/index.htm
City of Toronto Green Roof By-law Adopted by Toronto City Council May 26, 2009
Green Roof required for all new development above 2,000 m2 Gross Floor Area.
Green Roof required for all new development above 2,000 m2 Gross Floor Area.
Graduated coverage requirement ranging from 20-60% of the available roof space (excluding industrial).
Coverage requirement for industrial buildings starting in 2011, equal to 10 percent of the available roof space up to a maximum of 2,000 m2.
Available roof space = total roof area excluding areas designated for renewable energy, private terraces and residential outdoor amenity space (to a maximum of 2m2/unit).
There are approximately 135 built green roofs totaling more than 119, 775 sq. ft.
6. Federal Green Roof Incentive and Guidance
GREEN ROOF TAX INCENTIVE INTRODUCED TO US CONGRESS
Senator Maria Cantwell (WA) Introduces Green Roof Tax Incentive
Senator Maria Cantwell from Washington State introduced the Clean Energy Stimulus and Investment Assurance Act of 2009 (S.320) legislation on January 26 that, if adopted, would provide financial incentives for commercial and household green roof installation. Green Roofs for Healthy Cities and the American Society of Landscape Architects worked together to help draft the section of the bill that is focused on the green roof incentive.
Under section 506 of the bill, residential and commercial property owners will receive a 30% tax credit for qualified green roof expenditures. The tax credit applies to both new and retrofit projects. It requires that at least 50% of the roof area be covered with a green roof. If adopted, the bill will provide much needed green employment in areas such as design, manufacturing, installation and ongoing maintenance.
“In these times of economic uncertainty, growing the green economy and investing in clean energy technologies is the key to job growth and breaking the United States’ debilitating dependence on foreign oil,” said Senator Cantwell. “While installing a green roof may seem like a small step, these upgrades save energy, filter and absorb pollution, and store carbon. As individuals and businesses continue to look for ways to combat high energy costs and improve the health of their neighborhoods and environment, providing green roof incentives just makes sense.”
Stormwater Management for Federal Facilities under Section 438 of the Energy Independence and Security Act
Stormwater runoff in urban areas is one of the leading sources of water pollution in the United States. Traditional urban areas typically include large areas of impervious surfaces such as roads, sidewalks and buildings. These impervious surfaces prevent rainwater from infiltrating into the ground, and as a result, stormwater runs off these urban areas at higher rates and volumes. These higher stormwater rates and volumes can cause increased flooding and erosion, and more pollution to surface waters, among other impacts.
Under the new Section 438 of the Energy Independence and Security Act of 2007 (EISA), federal agencies have new requirements to reduce stormwater runoff from federal development and redevelopment projects to protect water resources. Federal agencies can comply using a variety of stormwater management practices often referred to as "green infrastructure" or "low impact development" practices, including for example, reducing impervious surfaces, using vegetative practices, porous pavements, cisterns and green roofs.
See: http://www.epa.gov/owow/nps/lid/section438/
Tuesday, February 2, 2010
Benefits of Green Roofs
Aesthetic Improvements
Waste Diversion
Storm Water Management
Reduction of Heat Island Effect
Improved Air Quality
New Amenity Space
Local Job Creation
Increased Ecological Biodiversity
Improved health and well-being
Education opportunities
PRIVATE BENEFITS
Energy Efficiency
Increased Membrane Durability and Longevity
Storm Water Management
Reduction of Heat Island Effect
Improved Air Quality
New Amenity Space
Local Job Creation
Urban Agriculture
Thursday, December 10, 2009
EPA has issued new guidance for stormwater management
CONTACT:
Enesta Jones
jones.enesta@epa.gov
202-564-7873
202-564-4355
FOR IMMEDIATE RELEASE
December 8, 2009
EPA Releases Guidance to Help Federal Facilities Better Manage Stormwater
WASHINGTON – The U.S. Environmental Protection Agency (EPA) has issued guidance to help federal agencies minimize the impact of federal development projects on nearby water bodies. The guidance is being issued in response to a change in law and an Executive Order signed by President Obama, which calls upon all federal agencies to lead by example to address a wide range of environmental issues, including stormwater runoff.
"EPA is proud to issue this new guidance to help federal facilities reduce stormwater pollution,” said Peter S. Silva, assistant administrator for EPA’s Office of Water. “By taking these steps to create more sustainable facilities, federal agencies can lead by example in reducing impacts in the local watershed.”
EPA worked closely with other federal agencies to develop this document, which provides background information, key definitions, case studies and guidance on meeting the new requirements of the Energy Independence and Security Act of 2007.
Under the new requirements, federal agencies must minimize stormwater runoff from federal development projects to protect water resources. Federal agencies can comply using a variety of stormwater management practices often referred to as “green infrastructure” or “low impact development” practices, including reducing impervious surfaces, using vegetative practices, using porous pavements and installing green roofs.
EPA is using sustainable techniques for reducing the effects of stormwater runoff at its facilities, such as installing a 3,000 square foot green roof as well as using rain gardens and cisterns to capture and reuse stormwater.
Stormwater runoff in urban and suburban areas is one of the leading sources of water pollution in the United States. Runoff can cause increased flooding and erosion and more pollution to surface waters.
More information on the guidance: http://www.epa.gov/owow/nps/lid/section438/
Note: If a link above doesn't work, please copy and paste the URL into a browser.
Thursday, November 5, 2009
TRUCK FARM
Wednesday, November 4, 2009
The green roof at the Museum of Contemporary Art, Denver
This is Colorado's answer to Sedums. Who needs Sedums when you can have Physaria bellii, native to the Front Range.
Green Roofs and the Climate Smart Loan Program
Tuesday, October 27, 2009
Toronto! cities alive!
Friday, October 9, 2009
Denver Justice Center
This is a new install as of this week with Sempergreen mats on the Denver Justice Center
The mats have a similar sedum pallet compared to the Steamboat residence green roof. (which is doing great).
It will be interesting to see how the mats respond to the Denver climate.
The substrate layer underneath is 4" minimum and at some places up to 6". The base of the green roof is a Hydrotech hot fluid applied membrane.
We installed 7500 sq ft of green roof between 9am and 1pm with 6 guys.
With the right amount of maintenance this should be a stellar green roof in Denver that hopefully will boost the industry here in Denver." Dick Bernauer, Sempergreen