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Biodiversity and Semi-Intensive Green Roofs

Green Team at Green Roof Technology, - Tuesday, June 26, 2012

By Kat Harrold

Photo by ~ Jorg Breuning

They say variety is the spice of life and this indeed tends to be the case when creating a green roof to promote biodiversity.  Green roofs with both intensive and extensive portions have been found to support the highest amount of biodiversity.  The combination of sedum meadow, grasses, and shrubs provides not just food but shelter for several species.  More information covering biodiversity on semi-intensive green roofs can be found on our case studies page in "Where the Beetles are Crawling and the Honey Bees are Humming." 

Visit us next week as we conclude our biodiversity segment with biodiversity on extensive green roofs!



Revolutionary Philadelphia Green Roof

Green Team at Green Roof Technology, - Thursday, June 21, 2012

By Kat Harrold


Image by Realen Properties

Philadelphia has one of the most progressive green roof programs in the country.  Their support for green roofs in based on an aggressive stormwater management plan to hold all run off on site.  Beginning late this fall, The Philadelphia Convention Center Parking Facility will open utilizing an architectural marvel featuring a combined blue roof and green roof system designed by Green Roof Technology and Realen Properties.

Green roofs and blue roofs are both great for capturing stormwater onsite.  Green roofs retain water by acting like a giant sponge while blue roofs hold the water on the roof similar to a rooftop swimming pool.  Blue roofs may hold more water than green roofs during intense storm events, however the standing water can create stress on the building and breed mosquitoes and bacteria.  The revolutionary green roof on The Convention Center Parking Facility combines only the best of both these technologies.  The green roof has an extra deep profile affording higher water storage capacity.  In addition to the added growing media, a specially designed insert for the roof drains holds water up to a couple of inches within the lower layers of the growing media.  When a 100 year storm event occurs this insert has an overflow mechanism allowing the roof to drain freely once the max saturation level has been reached.      

Beauty and intelligence are key to the success of this project.  Not only is the function of the green roof innovative and practical, the aesthetic will be just as exquisite.  The green roof will be visible from the Philadelphia Convention Center and accordingly will feature an eye catching seasonal display of color through a mixture of native ever greens, grasses, and perennials.  Crocus, and daffodils burst with color in the spring providing seasonal interest.  In the fall and winter months scarlet mahonia and evergreen ferns add to the festive decor.

Creating Biodiversity Through Rooftop Farming?

Green Team at Green Roof Technology, - Tuesday, June 19, 2012

By Kat Harrold


Photo By ~ Kat Harrold

Rooftop farming has the allure of self-reliance in a world of food uncertainties.

It is well known that urban agriculture on rooftops has recreational and educational value. However when it comes to economy and ecology these little pieces of intensive used land in polluted cities are more than questionable.

Depending on crop selection rooftop farms can provide habitat for several pollinators. At the same time they also provide food and shelter for insects, birds, and small mammals that might not be wanted. On ground remote locations it is very difficult and labor intensive creating a natural balance among wanted and unwanted organisms. Finally it depends on your goal, the time you like to invest, how much additional weight your roof can carry and last but not least your experience and knowledge in farming on impervious areas. Potentially urban agriculture on roofs or rooftop farms can be a diverse environment or – most likely - a monoculture stage for chemical warfare between man and nature.

Join us next week as we cover bio-diversity on semi-intensive green roofs!

Pittsburgh Goes Green

Green Team at Green Roof Technology, - Thursday, June 14, 2012

By Kat Harrold


Photo by Jorg Breuning

This past week Kat Harrold joined Ian Cooke of Monrovia and Mike Coraggio from EcoWalls for an ASLA green wall lecture series.  The trio gave an informative presentation on vital elements to consider from design phase to maintenance of green walls.

Ian charmed the audience with illuminating and entertaining descriptions of key specimens to utilize for climbing green walls.  He also provided a nice over view of different systems and materials to consider when selecting green wall support systems.

Kat provided detailed climbing green wall information from a case study of a recent project.  The case study discussed the evolution of the project from the architects concept drawings to plant selection and custom planter designs.  This project demonstrated how once can create an inexpensive and ecologically effective outdoor green wall on a LEED retrofit.

Mike finished up the presentation with beautiful creations that only he and the Imagineers of Disney could dream up.  Intensive green walls for both indoor and outdoor displays lit up the screen with a variety of themes and ornate designs showing the true aesthetic potential for this green medium.




Biodiversity on Intensive Green Roofs

Green Team at Green Roof Technology, - Tuesday, June 12, 2012

By Kat Harrold

Photo By ~ Jorg Breuning

Intensive green roofs with great media depth and plant selection offer ample opportunities for biodiversity.  Ramps or tiered levels offer roof access to non-aerial fauna setting the stage for the introduction and interaction of the surrounding ecology.  Just because a large animal such as a bear or moose may inhabit the local area does not mean that the intensive green roof must attract it to make the biodiversity effort a success.  Creating an environment which supports a variety of plants and fauna on the lower levels of the food chain benefit the entire food web for the surrounding area.  

Visit us again next week as we discuss biodiversity and rooftop farming!

Creating Biodiversity on a Green Roof

Green Team at Green Roof Technology, - Monday, June 04, 2012

By Kat Harrold


Photo by ~ Jorg Breuning

Creating biodiversity on a green roof or green wall is significantly different than restoring it on ground level.  On a rooftop there is no preexisting ecology to enhance; everything is from scratch.  In most cases the growing media is drastically different from the soil down below which in turn dictates what ecology can be supported.  Accessibility, high winds, and proximity to the sun can also be challenging issues for organisms.

Studies show that plant selection and depth of growing media have a greater influence on the biodiversity of a green roof than height.  In the translation of research covering the biodiversity of green roofs, “Where the Beetles are Crawling and the Honeybees are Humming,” the biodiversity found on green roofs as tall as 400 feet were comparable to that of lower green roofs.

Tray or modular green roof systems create the visual impression of a green roof by placing a series of planters close together.   The history of German trays, introduced in 1978, show that in most cases the performance of pre-planted boxes fail to meet performance and maintenance expectations.  The composition of a modular system simply does not provide the right set-up to reliably enjoy the 30 to 50 year lifespan expected from a built up equivalent system.  Additionally there tends to be incredible amounts of species die back during the first 5 years creating a sparsely vegetated monoculture setting.  These factors create a very poor and unreliable environment for biodiversity to take place.

Visit us next week for more information on bio-diverse intensive green roofs!



Engaging the Senses

Green Team at Green Roof Technology, - Thursday, May 31, 2012
By Kat Harrold


Photos by ~ Green Roof Technology

When designing green roofs which encourage human interaction it is important to keep in mind the 5 senses, taste, touch, smell, sight, and sound.  

Taste – While the a green roof may be a tough environment for some vegetation to grow, there are still several edible herbs that can provide delicious accents to a meal or tea.  Mint, chives, parsley, cilantro, thyme, oregano and rosemary are just a few edible herbs that thrive on extensive to semi-intensive green roofs. 







Touch – Flowing grasses with prickly seed heads and the fuzzy leaves of Hieracium create a dynamic contrast to the lush springy texture of succulents and sedum.  Small berms can be used to integrate ornamental grass areas into extensive green roofs while keeping weight restrictions in check.








Smell – Closely related to taste, many culinary herbs can also employ a richly scented environment.  Other fragrant options for green roofs are lavender, polyantha rose “the Fairy”, sage, and Echinacea Daydream.







Sight – One of the many beautiful things about a green roof is there are a multitude of drought tolerant plants which provide year round interest.  Late winter and spring welcome a blast of color from crocus, Sedum hybridum “Czar’s Gold,” Dianthus, and Allium.  Summer brings forth a variety of extended bloomers including Sedum kamtschaticum, Hieracium, and Telinum.  Fall offers a variety of color from Aster Purple Dome, Snowcap Shasta Daisy as well as a red and gold glow from the foliage of several sedums.  Winter blankets the roof in festive greens and reds.  Sedums kamtschaticum, ‘Czar’s Gold,’ ‘Blue Spruce,’ and spurium ‘John Creech’ maintain their green foliage while Sedum spurium ‘Fuldaglut,’ moranense, album ‘Coral Carpet,’ and rupestre ‘Angelina’ brighten the season with displays of red and gold.



Sound – Green roofs have the to power to not only clean rain and air pollution but sound pollution as well.  When designing a green roof to function as a patio space, consider using plants which rustle in the wind such as grasses.  The tall reeds create white noise which helps mask the sound of a busy street.   









Green Team at Green Roof Technology, - Tuesday, May 29, 2012

By Kat Harrold

The American Heritage Scientific dictionary describes biodiversity as, “the number, variety, and variation of different organisms found within a specific geographic region.”  

A biodiverse environment can have both native and introduced species.  A mono-culture of a native species can be just as detrimental as having a monoculture of an invasive species.  The key word in a biodiverse environment is diversity.  For an environment to thrive there must be competition and prey predator relationships to strengthen the key players within that ecology.  

On ground level, efforts to promote biodiversity are typically geared toward enhancing or restoring the surrounding to preexisting environment.  Preexisting elements such as soil and accessibility play a critical role in what species can thrive there.

As a result of development, there exists a lot of fragmented habitat creating connectivity and migration challenges.  Some creative ways that connections can be made between severed environments are wildlife bridges, tunnels, and green corridors.  Wildlife bridges and tunnels serve not only as key instruments allowing safe passage from one environment to the next, they also cut down on traffic accidents.  Green corridors are often an area around a stream left wooded in a heavily developed area.  This area serves as a haven for bird and mammal migration.

While green roofs can provide habitat for biodiversity to exist they often have a similar challenge of disconnect for non-aerial fauna.  To create access to a green roof one option would be to design the building so that it is built into a hill or create a ramp which wraps up the side of the building to the roof.  Terraced landings or steps can also be used to promote access to the roof.  Species and size of fauna depending, green walls consisting of vines can also be a method of access.  





Begining of a Green Generation at the Episcopal Academy

Green Team at Green Roof Technology, - Thursday, May 17, 2012

By Kat Harrold


The Episcopal Academy -  Photo courtesy of

The Episcopal Academy has long been known for leading the way in academic excellence.  Adding to this commitment to enhance the mind, body, and spirit of it's pupils the academy will be installing a series of green roofs on their academic buildings under the guidance of Green Roof Technology.

The green roofs will feature an extensive greenroof set up composed mainly of sedum plants and hardy herbs.  The green roofs will be used to promote local ecology, aesthetic appeal, in addition to being an interactive learning tool.  Visible from high traffic areas in the building, these green roofs will be an ever present and key tool in promoting the latest in sustainable practice and design.




Green Power for NYC

Green Team at Green Roof Technology, - Monday, May 14, 2012

By Jorg Breuning

Sun Root with solar panel at the NYC Dept. of Parks and Rec, Randall's Island ~ Photos by Jorg Breuning

Big things are happening in New York!

The first Green Roof & Solar Panel Installation by Green Roof Technology is now powered-up. A few weeks ago Green Roof Technology and the New York City Department of Parks and Recreation installed the first non-roof-penetrative PV-Green Roof combination in Northern America.  The installation took place at the New York City Department of Parks and Recreation building on Randall's Island as an addition to their already extensive green roof system collection

The Sun-Root system - promoted by Green Roof Technology - is the most advanced system solution that considers enhanced water storage for the plants and optimized evaporative cooling for solar panels at the same time.  Drought tolerant succulents were graciously donated by Mother Plants and the growing media was provided by Rooflite. This green roof system is truly unparalleled.  The project is accessible by appointment. Please contact

Learn more about the amazing Sun-Root™ System.  (YouTube Video) Click on the picture for more information on the marvels of combining solar and green roofs on our webpage. 







Sun Roots soaking up the sun after installation at NYC Dept.
Parks and Rec Building ~ Photo by Jorg Breuning


The NYC Department of Buildings oversees the property tax abatement's for the installation of solar and or green roofs in New York City. To find  out more about application deadlines and tax abatement's click on the NYC buildings logo above.

Green Roof & Solar Panel Installation in NYC  NYC Buildings

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