Green roofs are an integral component of sustainable development in the arid West.
Friday, May 27, 2011
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: 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,Municipal, state and federallypublic 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 set of rules the. The owner has a right to limit or restrict access to the area “PPMMP”.the ,(defined here perhaps as visitors not owners/taxpayers) g
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 (“” 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?
Of the three sites, only one is “open” or readily accessible to the public. The other two are limited to tenants; one is an office building and the other is an apartment complex. Based on multiple site visits, one might conclude that all three sites are underused. Two of the sites have recreational playgrounds in the forms of a basketball court, tennis court and putting greens but the day we visited, the wind was howling and nobody was around. The only users we can surmise would be office workers on lunch break who stay to eat a sandwich or salad around , going back to work after an hour or so. Based on conversation with the management of the apartment complex, we found that the roof garden there is used mostly for barbecue parties.The real users or inhabitants of these secondary spaces might be the insects, birds and other flora, who make these brief respites from the harsh urban core their home or way station.
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
sa “LU”, currently a professor at Harvard“”…“LUCOS…”)…” We think these secondary spaces are such a system comprised of i.e. storm water drainage systems that a 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
“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