Green Roof Design Guidelines and Maintenance Manual

Now available for free - go to GrowWest.org to download:

Design Guidelines and Maintenance Manual for Green Roofs in the Semi-Arid and Arid West by Leila Tolderlund, LEED AP, GRP, University of Colorado Denver - in collaboration with Green Roofs for Healthy Cities, City and County of Denver, Environmental Protection Agency Region 8, Urban Drainage and Flood Control District, Colorado State University and GrowWest.

This document will give you an understanding of the following:
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

Green roofs have many benefits that are increasingly being identified, measured, and acknowledged by the general public. These benefits include: controlling quantity and quality of stormwater, cooling and cleaning the air, creating habitat for wildlife, conserving energy, extending the life of the roof, and improving aesthetic environments in work and home settings.

Now available for free - go to GrowWest.org

Sky Trapezium at MCA

The Cacti are flourishing along with the Erigeron.
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.

The 2009 watering schedule for these native and climate appropriate plants: irrigation turned on in August, watered for 2 months, 10 minutes a week until October.

Sky Trapezium at MCA

Spring on the roof of the Museum of Contemporary Art with not a sedum in sight and the alpine dapne smells so sweet.

Green roof press

This article in National Geographic is very well done with great photography of course...

http://ngm.nationalgeographic.com/2009/05/green-roofs/klinkenborg-text

NYC Green Roofs

Ahhh.. the Highline a vastly publicized yet well deserving converted rail track to green roof in NYC. If you have never been, strolling among native grasses and streams of flowing exposed aggregate concrete, it is well worth it( it was worth it for me even in 15 degrees). The design provided by Field Operations and a well endowed budget make this an incredible experience. I have also included a roof visible from the 18th floor lounge of the Standard Hotel designed to echo the highline by Amy Falder and Chris Brunner of Convert, a New York Green Roofs Company.

Existing Policies

Green Roof Policy in the U.S.

(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/

Benefits of Green Roofs

PUBLIC BENEFITS

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