Lightweight Rooftop Vegetable Gardens (Finalist.)
The Food and Water Institute (FWI)
Objective
The objective of Rooftop Gardens Inc. is to design and build year-round rooftop vegetable gardens that are lightweight so they don’t exceed the structural capacity of standard flat rooftops. These gardens will serve private citizens, restaurants, community groups and schools by providing local, organic produce on site for kitchens and nutrition programs.
Background
Toronto offers an abundance of flat, open rooftop spaces that are perfect for vegetable gardens. Green roofs are rapidly gaining popularity in Canada, but their potential could be greatly increased if we consider the question: what if we use rooftops for agriculture? In Toronto we have a vast potential to grow tonnes of food on our rooftops, yet large rooftop gardens are rare. This is due to the short growing season, as well as the cost and structural constraints of incorporating a rooftop garden suitable for growing vegetables. Rooftop Gardens Inc. offers solutions to these obstacles, as outlined below:
Rooftop Gardens Inc. solutions to urban agriculture obstacles for Canadian cities:
Space
Obstacle: Limited space, soil may be unsuitable, theft from community or public gardens
Solutions: Acres of flat, open, sunny rooftop spaces; fresh organic soil and compost; privacy
Water
Obstacle: High irrigation needs, access to water, fertilized water runs off into sewer system
Solutions: Collect rainwater; drip irrigation system conserves water; fertilized water is recycled within the system
Growing Season
Obstacle: short May-October season; harsh winters
Solutions: four-season harvest; sustain cool-weather crops in passive-solar, lightweight greenhouse
Technology
Obstacle: Intensive; heavy soil requirements; most rooftops cannot structurally support a vegetable garden
Solutions: Lightweight semi-hydroponic or aeroponic containers; organic fertilizers to maximize yield; compost garden waste for use as fertilizer
Knowledge
Obstacle: Lack of awareness with respect to horticulture and where our food comes from
Solutions: Showcase health and environmental benefits of local, organic food; educate community about urban agriculture through our partner organization, The Food and Water Institute (FWI)
Innovation
Rooftop Gardens Inc. designs are unique because they are lightweight and enable year-round food production:
- Designs incorporate the use of lightweight semi-hydroponic or aeroponic containers;
- In Ontario, the average load capacity for a flat roof is 195 kg/m2 and an intensive green roof generally imparts loads of around 450 kg/m2 and up. A semi-hydroponic garden built by Rooftop Gardens Inc., complete with water, soil, mature vegetation, and a greenhouse will weigh no more than 100 kg/m2;
- Containers are watered via drip irrigation which results in little wasted water, no soil erosion and uniform distribution;
- Organic fertilizers and compost teas are easily added to the irrigation system and distributed to plants;
- Irrigation and fertilization can be automated with a timer to minimize maintenance;
- Gardens can be made more self-sufficient through on-site composting, seed saving, and rainwater capture
- We provide access to organic vegetable seeds and plants that have been grown for generations on a rooftop, and are thus adapted to the environment
- Four-season gardening is achieved using innovative lightweight, inflatable greenhouses that enable the continuous harvest of cool weather crops such as salad greens throughout the winter months.
Pilot Garden
The SkyGarden, located at the University of Toronto, is our pilot installation, developed in collaboration with the Food and Water Institute and the University. In two growing seasons SkyGarden has produced over 350 kg (800 lbs) of organic vegetables in a surface area of only 50 m2. The SkyGarden is self-sustaining: plants are grown from seed collected from the previous year’s harvest and garden waste is composted and used as a soil amendment. Other features of the garden include a honeybee hive and a solar dehydrator, built through workshops facilitated by FWI. Upcoming additions to the garden include a lightweight greenhouse and experimental cold frames, to continue the harvest year-round.
Cost
Individual containers retail for $50. Overall cost depends on the number of containers and whether or not an irrigation system is required. Our system design is approximately $120 per m2 for large installations (>100 containers, or 50 - 100 m2). This cost estimate is based on the design of our pilot garden, and includes an automated drip irrigation system. Our pilot garden yields indicate that based on the value of organic produce grown alone, the payback time of the capital cost for our system is 2-3 years.
Contrast this to a traditional green roof which costs approximately $150 - $375 per m2 for an intensive system, i.e., one with soil deep enough to grow some vegetables. This cost does not include an irrigation system, prices of which vary widely as they are generally customized for the specific design. However, it is not uncommon for the irrigation system to nearly double the cost of the installation.
Benefits
Rooftop Gardens Inc. offers an affordable and effective solution overcoming obstacles in constructing urban rooftop gardens. In doing so, the community can dramatically reduce its ecological and carbon footprints and experience the many health and environmental benefits of growing and eating local, organic and seasonal food.
Direct Reductions - Heating and Cooling Energy Savings
Direct emission reductions within the city are related to savings on heating and cooling costs. Studies have shown that vegetation on a building exterior (rooftop, walls) can provide a measure of insulation and reduce the energy needed to control the temperature of the interior of the building. Rooftops are particularly important because, for many urban buildings, they have the hottest temperatures in the summer and they are the site of the most heat loss in the winter.
Heating:
A study by researchers at U of T and Environment Canada demonstrated that green roofs reduce energy consumption in winter by preventing heat loss. For a typical mixed-use (residential and commercial) 3-story space in downtown Toronto, the green roof resulted in a reduction in heating energy of 34% or 6015 kWh for the winter season. That translates to 1125 kg of CO2 for just one building, based on the TAF conversions. For a residential home, the same study estimated heat energy savings of ~5% or 385 kWh, which translates to 72 kg of CO2 emissions per home.
Cooling:
A City of Toronto study noted the benefits of vegetated rooftops in decreasing air conditioning requirements for the buildings. They calculated energy savings on air conditioning at 4.15 kWh/m2 of vegetated rooftop. This translates to 0.77 kg of CO2 per sq. meter of vegetated rooftop.
Reduction of Urban Heat Island:
In large cities, non-vegetated surfaces like rooftops and concrete absorb solar radiation, the surface temperature rises, and with it the surrounding air temperature. This is the urban heat island effect. So, if we increase urban vegetation coverage we can lower the air temperatures and that heat island effect. Adding this vegetation to rooftops turns a liability into an asset. At a large scale, in theory we could reduce the air temperature enough to lower air conditioning requirements in summer.
A 2004 City of Toronto study on the benefits of green roofs concluded the following:
- widespread implementation of vegetated rooftops would reduce air temperatures in Toronto by 0.5 to 2 degrees Celsius
- This translated to energy (cooling) savings of 2.37 kWh/m2 of vegetated rooftop
- The CO2 emission reduction from power generation translated to 32,300 metric tonnes per year
Indirect Reductions - Food Miles
Developing low cost, low energy, four-season rooftop gardens will provide year-round, local and organic produce in the urban environment. In doing so, the potential decreased “food miles” is significant and will act to reduce greenhouse gas and smog causing emissions associated with food transportation.
Local, organic food has a much lower associated carbon footprint than conventionally grown food which has travelled great distances from farm to dinner plate, and that uses excessive chemical fertilizers and pesticides. In Toronto, local food items travel an average of 101 km versus imported food items which travel an average of 5,364 km. A local study on food miles done by Waterloo Public Health concluded that 10 commonly consumed foods in the region had traveled an average of 4,497 km and accounted for 51,709 tonnes of greenhouse gas emissions annually. The study also pointed out that these were foods that were able to be produced within the region. The same study showed that selecting locally-sourced foods, rather than imported foods, would result in an annual reduction of 49,485 tonnes of greenhouse gas emissions in that region alone, the equivalent of taking 16,191 cars off the roads. The potential emission reductions in Toronto with increased rooftop agriculture are significant. In addition, extending the harvest to the entire year using passive energy, lightweight greenhouses increases the availability of local food during winter months when food is imported in even greater quantities and/or produced in energy-intensive, heated greenhouses.
Indirect Reductions - Organic Agriculture
Organic agriculture is more effective at capturing atmospheric CO2 and sequestering it in the soil as beneficial organic matter; in contrast, conventional farming results in a net release of CO2 to the atmosphere. These results are based on a long-term (23 year) study by the Rodale Institute. The same study also estimates that converting one medium-sized farm to organic production stores an amount of carbon in the soil equivalent to taking 117 cars off the road. For 10,000 farms that is equivalent to taking 1,174,400 cars off the road.
In addition, eliminating the use of pesticides, herbicides, and fertilizers made from fossil fuels will further reduce the impact of these rooftop gardens.
Heather Wray is in the final year of her PhD in civil and environmental engineering at the University of Toronto. She also has a MSc in ecology. Prior to beginning her PhD, Heather worked for a green building design firm in Montreal, where she designed and implemented greywater recycling and four-season gardening for local projects.
The Food and Water Institute (FWI) is a Canadian registered charity and believes that it is the right of all Canadians to have access to healthy food and water that is free from unwanted chemicals. The Food and Water Institute shares science-based information about food and water safety, and challenges consumers to make informed choices. FWI maintains SkyGarden at U of T, where educational workshops and seminars are held. Examples of workshop topics include composting, seed saving, building a solar dehydrator and urban beekeeping.
Casey Wong is an industrial designer and a founding partner at Citra design, a Toronto design consultancy specializing in high quality technical solutions for architecture, interactions and living. Citra design is working with Rooftop Gardens Inc. and FWI to develop and install an inflatable greenhouse concept at the University of Toronto SkyGarden.
Erika Richmond is finishing a masters in Landscape Architecture at the University of Toronto. Before beginning her masters degree, Erika operated a small green roof design and construction company in Vancouver. She has also worked at and volunteered at many urban agriculture projects in Toronto and Vancouver.
Rooftop Gardens Inc. will be self-supporting in under five years by charging consulting, installation and equipment fees to the individuals and organizations that purchase our products and services.
Revenues from the installation of three paid projects the size of SkyGarden (100 containers) would enable Rooftop Gardens Inc. to cover minimal operational expenses for a period of 12 months.
Funds from Climate Spark will allow Rooftop Gardens Inc. to 1) design and manufacture new innovative rooftop garden technologies, 2) establish an organizational presence by securing desk space and bringing on a paid intern, 3) establish a strong brand and develop and implement our marketing and communications strategic plan, and 4) support educational workshops and seminars to teach urban gardeners new skills in collaboration with the Food and Water Institute.
Comments
RE: Great idea!
Thanks Nick! I appreciate your comment about increasing food security!
i think that this is a very
i think that this is a very good idea and it will gain alot of suport in the organic crowd as all the food would be localy grown. also i think that this would be a good idea as it would creat jobs as people could sell there produce in the local farmers market. how would you address these problems
1) lack of sunlight in big cities
2) lack of roofspace for people with small or none existent roofs
also how do you plan to spend your maney if you win?
great idea!
Rooftop Garden Proposal
The idea is a fantastic use of space in the city and elsewhere, a great combination of green and healthy ideas to better what we already have. Two thumbs up!
RE: Rooftop garden proposal
Thanks for mentioning the health aspect...both environmental health and human health are improved with this project!
Maintenance
I like this idea a lot.. I can see a lot of grassroot restaurants going for this, assuming they can afford it and have the space.
Just a question -- who maintains the equipment, housing etc of Rooftop Garden after it has been installed? Is there a maintenance fee/schedule in place, or is it a warranty? Is there any risk for the owner?
RE: Maintenance
Thanks for your comment! We agree that restaurants would be a great fit for a project like this. We estimate that start-up costs are paid back in under three years, based on the value of the produce alone.
As for maintenance, there are a couple of options. Interested buyers we've spoken to so far all have an interest in doing the maintenance themselves. We would help with the installation and teach customers how to use the system. We're also available for follow-up consultations. In addition, our partner organization (The Food and Water Institute) offers workshops and seminars related to urban agriculture, and so they can transfer knowledge to owners about how to maintain their gardens.
So we like the idea of sharing knowledge about garden maintenance with owners and then having the owners perform maintenance themselves. In that way the knowledge spreads. There are other benefits as well, for example, a community group that has a strong environmental programming component could use the garden maintenance as a means of teaching skills to their members.
I should also stress that maintenance can be minimized. Our garden at U of T has a drip irrigation system hooked up to a timer. So the garden is automatically watered every day for a set amount of time and is not over- or under-watered. The same garden also has a system in place to automatically dispense liquid fertilizer to the garden. So the only maintenance required involves a refilling the fertilizer reservoir (2x a month), modifying the watering timer if necessary as in the case of very hot temperatures, and harvesting vegetables.
We found that minimal weeding was required because a) we covered the soil with mulch and b) less seeds were being transported in (airborne) because we're on a rooftop. We also don't have pest issues (squirrels, raccoons) because they can't access the garden.
In terms of a warranty, we would offer a warranty on the containers and irrigation system components that we provide. The details of the warranty are still being worked out, but would likely be 10 years for any natural physical or chemical degradation of the system components.
I understand that maintenance is not ideal for everyone, even if it is minimal.
There is definitely potential to collaborate with a group providing garden maintenance, including some other Climate Spark applicants! So this is an avenue we're going to explore :)
Maintenance
Low maintenance would increase the accessibility of the proposal greatly. To what extent are these minimal input gardens used?
A system for pairing a caregiver with gardens could increase support for the project in some communities. A renter living in an apartment building could support an individual with less time or capability for maintaining the garden, and spitting the spoils.
Maintenance
Hopefully the people that want to install productive gardens will enjoy gardening themselves, and won't see it as "maintenance" work, but rather, gardening. That said, there are organizations that match people with gardens with willing gardeners, Fresh City Farms and Sharing Backyards, for example, and this could be an option for garden owners that don't want to garden themselves.
Rooftop Greenery, what our world needs!
In this day an age of increasing urbanization, we are in dire need of whatever greenery we can get.
Rooftop Gardens provides an efficient answer to this imbalance.
When urbanization spreads horizontally, then why not help nature spread vertically!
Great idea Rooftop Gardens!
rooftop vegatable gardens
As the enviroment faces additional stresses from urbanization and arable land is on the decline solutions need to be found to feed the ever growing world populations by implementing workable and practical ideas. The use of a system that would allow us within the urban centre's to provide a renewable food source is both practical and workable. If as individuals within urban areas we can reduce our dependancy on commercial farming operations this would potentially impact the supply of an important food source to others while providing ourselves with wholesome organic food. Count me in!
Great idea
Lots of direct and indirect benefits.
Is the payback calculated on year-round growing with a lightweight green house covering? If so - is the cost of this taken into account or is the payback even lower if you get "the whole kit & kaboodle" of garden, irrigation & covering? How much is the approx. cost of the green house?
RE: payback times and greenhouse costs
The payback time calculated is based on the summer season only. We are currently in our first year of pilot testing the four-season gardens so we don't know the payback time for the entire kit. I would estimate it would be the same or lower, based on the market value of the kind of specialty organic greens you can harvest in winter.
The average cost of a greenhouse would be approx. $6000 - $8000.
rooftop garden
Taking advantage of rooftops that receive full sun all day makes sense. Also, the flexibility of a system that can be tailored to any space and budget means that almost anyone could install a lightweight rooftop garden. Great teaching tool for schools with the benefit of fresh food.
Toronto needs more rooftop veggie gardens
I believe rooftop gardening is a great way to utilize urban space and reconnect people with how food grows. I'm curious as to the time, labour, and skill required to manage the garden, who will manage the gardens, and if ongoing maintenance or consultations has been considered as additional revenue streams.
RE: Toronto needs more rooftop veggie gardens
Thanks Young Urban Farmers!
The labour involved can be minimized if the irrigation and fertilization is automated - for sure, this would be the most time consuming part if you had to do it by hand.
As you know, there are obviously other labour considerations. It takes time to ready the containers in spring, and to do planting and harvesting throughout the seasons. As for skill, we have several volunteers that had no prior knowledge of horticulture and they have had no issues with the maintenance requirements.
We've considered including some ongoing maintenance or consultation as part of the services we offer. In addition, I think this is a good opportunity to partner with other organization, such as YUF, that already have the skills and the people to offer garden maintenance. We should discuss more...I will send an email to your group!
Amazing work Food and Water Institute at UofT
Thank you for all the work Heather you and your team are doing.
I know that the Liv Green Grant that you earned will be put to good research and development work that will push forward the developments of Greenhouses on roofs.
The leading expert in greenroof Prof. Hitesh Doshi http://www.ryerson.ca/graduate/buildingscience/bios/Bio_Hitesh Doshi.pdf
Estimate there are 50,000,000 sq meters of roof top space in the GTA. that is
500,000,000 half a billion square feet.
The growth potentional of the food production idustry on roof tops is incredible.
Good Luck on all future endevors.
Big questions to ponder
How can you work on metrics and the analysis of carbon offsets?
How will you scale up operations to retro fit roofs in the coming 3-5 years?
Yummy idea needs partners
I love how you've solved some basic problems of roof top gardening by reducing the weight of the gardens. I think you've successfully addressed the social good of local organic food with the personal benefit of growing ones own organic food. But as a homeowner with a flat roof, I'm still asking myself if I want to build a ladder up to the roof or even if bylaws allow it. I'm also concerned I will kill all my vegetables from neglect.
I'd like to see the proposal be more convincing that "accessing the rooftop will be safe and easy" and that "I don't have to do anything and my tomatoes will come out fine". I'd like to see a partnership with a rooftop-ladder installation company too.
Finally, I don't get a sense of the scalability of this. If each rooftop requires a PhD thesis to be written about it, and judging by the proponents this may be the case, then you should look at licensing your technology out to nimble installation contractors. Finally, I'd like to see a partnership with people who will do the maintenance and harvesting too -- some of whom might be found among other Climate Spark proponents. This might be also be an additional service that homeowners could pay for.
Great idea and good luck. I gave you an 9.
A great idea all around!
such a good way to make use of all the space available on rooftops and a great means to get more and more people involved / connected with the process of growing food. best of luck!
Great Proposal!
This is an excellent, easy to maintain way to obtain high yeilds on underutilized rooftop spaces! Good luck!
Bright Idea - Maintenance Issues
I am impressed by the potential to transform what is now negative space into positive space. Especially attaractive is the potential to reduce cooling costs.
Like some other reviewers I am concerened about the success of the gardens if they are not professionaly mannaged.
Perhaps the group could partner with a landscaping/gardening firm that could perform the long term maintenance of gardens for large clients after instalation. Or at least have some to recomend to clients.
RE: Bright idea
Hi, thanks for commenting!
We, too, are encouraged by the potential savings on cooling, although there definitely a need for more studies to figure out the exact impact of our proposed systems on building heating and cooling requirements.
And thank you for the suggestion of partnering with a garden maintenance company. We think this is a great idea and a good opportunity for collaboration with like-minded organizations!
AMAZING GOAL
What a fantastic way to transform the urban fabric!
Great Idea!!
A smart use of space, environmentally-friendly, and so much potential for urban chefs to use local, seasonal produce in their restaurants. Rooftop gardening is a great idea all around!
A fantastic and necessary idea!
This is a project that is long overdue. This should unquestionably be chosen and as a Torontonian, I support it 100%!!
Up on the Rooooof
Great idea - elegant solution to a systemic challenge.
As I read the project description, I had many of the same questions as Matt. How do I know if my roof can event sustain the weight of this garden - or the garden plus me? How do i get on my roof - what bylaws are in place that limit my access to my own roof. I assume I would need a handrail? I think anticipating some of these basic questions around safetly, bylaws and owner-requirements would help me to wrap my head around the viability of the idea.
Where and how would you market the idea? And who is your target market - where will you get the greatest response?
I would also like moredetail about the greenhouses. What percent of your market do you think would go for this option? my guess is it would be minor... i like gardening but don;t see myself doing it in Winter, even with a greenhouse.Simiarly, what bylaws or limitations might there be with adding a greenhouse to a residence or business?
Promising idea... questions looming!
Weight and water
In the new world of roof top agriculture it is very hard to streamline all the retrofits, because you have to have an engineer look and assess each and every roof and custom fit each roof.
There are so many weight and security issues prohibiting growing food on roofs still and the issue of Health Canada having on recycling rain water is still a big roadblock for us to grow and sell back to the public.
Saving rainwater and using it again would save a lot of energy and help irrigate the crop.
http://www.gdrc.org/uem/water/rainwater/rainwaterguide.pdf
How can the City of Toronto Green Retro fit incentive program help your cause?
Can you get the developers and condo owners involved in order to retro fit their roofs?
Weight and bylaw issues
I have been speaking to some aquaintences "in the know" and their thoughts are that the weight of the standard house will not be enough without reinforcements. Further, there will probably be a lot of red tape with bylaws.
The retrofit program is a great idea, but reinforcing puts an extra roadblock to project success. What screening will be done to ensure that the rooftops are stable enough?
RE: weight and bylaw issues
Hi, thanks for your input.
Agreed that working with the green roof incentive program could go a long way to help get rooftop vegetable production projects implemented. As I mentioned previously, we're working with councillors to make sure rooftop vegetable gardens would be eligible for the program.
And as for structural requirements, most flat rooftops should be okay for our system, provided the building is up to code. However, to be absolutely sure, it would be standard practice to have a structural assessment by a professional engineer prior to installation.
RE: Up on the Rooooof
Hi, and thanks for your comments and questions.
We can use Ontario Building standards as a general guide for rooftop weight allowances. However, the only way to for sure know the current loading capacity of your particular rooftop would be to have an assessment by a structural engineer. This is a fairly standard practice and it is recommended prior to the installation of any rooftop structure.
In terms of rooftop access and safety, existing regulations require that a railing be in place around the perimeter of the rooftop, and this railing must be 3.5 ft tall. With respect to access to the rooftop, there are no set standards but in general access should be easy and allow the movement of materials and equipment to and from the rooftop space.
As for target audience and response, we see the greatest interest from community groups and restaurants - facilities that could implement a larger growing operation and use the produce on-site. As for private citizens and homeowners, we see the most response and potential from people with balconies and patios - people who don't have access to a backyard gardening space. Another good potential target audience would be new condo developments which could offer a rooftop garden with plots as an incentive to residents and buyers.
The greenhouses, we agree, would probably only be of interest to a smaller audience. As for limitations, there are the same access and railing issues with the rooftop gardens. Rooftop gardens and associated structures like a greenhouse, installed by the building owner, are generally permitted under existing legislation. This is especially true if the greenhouse only covers a small portion of the roof area - it would be considered an extension of the roof structure and not an additional storey.
where does your garden grow?
Well this is a clever little idea isn't it? When you consider (a) how many rooftops there are in this city, and (b) the general shortage of vegetable gardens, well I guess what I'm getting at is that it seems like a perfect marriage, yin and yang and all that. I applaud your ingenuity.
I do like the idea.... but I
I do like the idea.... but I'm just not sure if there's suffecient wide-scale demand. I suspect that buildings with the larger surface areas (hospitals, schools, corporations) will be the one least able/interested in this solution (budget, cost, regulations, legalities).
working with bylaw/building regulators in advance to 'pre-approve' the solution?
creating corporate program to encourage the use of the garden (eg. as a company team building tool)
RE: I do like the idea...but
Hi Roger,
Thanks for bringing up some valid points.
With respect to demand, we're only seeing interest in this area growing, and it will continue to grow with the increasing concerns about food security and climate change. I think in the long term there will be a demand for more urban gardening space.
And large rooftops such as those for schools and corporations provide an opportunity to use the garden as a tool within the organization. They could be used as a teaching tool within schools, supply nutritional programs, supply kitchens, etc. As for corporations, you are absolutely right that it could be used as a team building tool or just a lovely space on-site that is of benefit to the employees.
In terms of working with regulators, we completely agree. The easier it is for these systems to be implemented, the better. We've been in contact with some city councillors who want to help us make systems such as ours eligible for green roof incentive programs, as well as an option for buildings that are required to install a green roof under existing by-laws.
lightweight Rooftop Vegetable garden
I think this is a brilliant idea. There are so many unused flat roofs that could by used for urban agriculture.
Consider bylaws and liability for safety of installers and users.
Good idea, but ...
In general, I think this is a great idea. Using the under-utilized rooftop space in the city for agriculture is excellent on many levels. However, having installed green roofs in the residential market for a number of years, I think there are a few issues with your proposal.
Emissions Reductions Potential
The studies you mention regarding reduction in heating/cooling costs and urban heat island effect ... those benefits are based on "traditional" extensive green roofs. Your system utlizes containers, which won't provide the 100% coverage that an extensive green roof does. I'm sure the containers do contribute in those areas, but I don't think it's entirely fair to use those statistics without at least mentioning how your system would be (slightly?) less effective in acheiving those goals.
Roof Loading
You are right in that a "traditional" green roof that could support vegetables would weigh in the area of 300kg/m2, which is pretty much an impossibility unless the roof has been designed for that weight. However, when you say that a flat roof in southern Ontario is designed for 195 kg/m2, you neglected to say that this is to account for the snow load. Any green roof -- or in fact anything else that is designed to go on a roof -- is going to require a loading capacity in addition to that figure.
In my experience, it is very difficult to retrofit a green roof on to an existing structure without reinforcement. This is simply because 99% of buildings are built to the minimum requirements and without thinking of future uses. Only 1 of my 40+ green roof installations was on an existing building; all the rest were designed to take the weight. I think you'll find this is even more true once you get into large industrial buildings (box stores and the like) where the developer will build to the requirement and not beyond, in order to maximize profit.
In any event, the services of a structural engineer are paramount, which will add to the cost of your system (and any green roof, of course).
Also, the addition of year-round green houses are going to involve additional loading issues: the weight of the structure and securing it against wind being the primary points.
Safety and Access
I'd like to hear some more about how you plan to satisfy the municipality in terms of safety and access issues. My understanding is that if you are creating accessible space above grade, you will need safety railings and stair access (i.e. no ladders). For the homeowner, this becomes an additional expense, takes up space on the property, affects the look of their roof, etc.. If all of that is already in place, then it's obviously not a problem. But I suspect that you are looking at using roof space that is currently unused, and therefore likely "inaccessible".
As I said at the begining, I think green roofs and roof top agriculture are fantastic ideas. It's the details of implementation that invariably cause issues, especially when trying to retrofit existing roof space. Hopefully you have solutions to all my concerns, and I wish you the best of luck!
- Colin Viebrock, Green Garage
RE: Good idea, but...
Hi Colin,
Thanks for commenting.
With respect to the emissions reduction potential, we agree that it is not exactly the same as a traditional green roof installation. And while our system will definitely contribute to reducing energy costs, nobody has quantified the particulars for a container garden. The best estimate we have is the measurements for traditional green roofs, which would be a close approximation. It's not perfect, we know, and i hope that we're able to do some research into the energy reductions from rooftop container gardens and greenhouses and actually be able to specifically quantify them.
For loading capacity, we agree that working with a structural engineer is important to determine the actual load bearing capacity of the roof in question, or if reinforcement is required. Working with new construction is obviously a great idea, especially in conjunction with the green roof incentive program, as a means to implement new rooftop vegetable gardens. In this case, our system also offer benefits of lower capital costs compared to traditional green roofs with the added benefit of food production.
As for the safety and access issues, we've tried to address that in some other comments. But you are right - access needs to be easy and safe (stairs, not ladders) and a railing would need to be in place.
Sky Garden has a lot of Potential
The idea of proliferating rooftop gardens makes a lot of sense. Of course winter is one of Toronto's challenges, but the potential of rooftop gardening needs to further developed in Toronto. GreenHereos was inspired by Laura Reinsboro "Not Far from the Tree" Campaign see video http://www.greenheroes.tv/webisode/3120283-Laura-Reinsborough. The Strength of the Lightweight Rooftop Garden proposal is that it could engender the same kind of postiive results as Not Far From The Tree. The challenge wil be motivating the community and finding ways to encourage particiaption in gardening - getting people invovled and inspired by the idea. Grass roots organizing will be needed and resources from agencies specializing in growing and building community will be needed.
A few more details on how to inspire the community to participate in rooftop gardening would be good but this is a great proposal!
RE: Sky Garden has a lot of potential
Thanks for your comment! We've seen a lot of great community participation with our pilot garden at U of T. It's truly a collaborative effort.
And we agree that community organizations are a great candidate for these systems because they reach a wide audience and there is the potential to engage the community and teach them the skills and benefits of organic urban agriculture.
Rooftop Gardens - Could they work on the Ground?
The concept is sound and is being proven in a university setting, where a number of factors are in play which may not occur when you move this out to other areas of the 416.
Questions in 2 areas
Capacity and viability:
- Do you have an inventory of roofs that you believe are easily accessible by the owner or the public . (Backup to your “abundance” assertion in the Background section)
- What is the cost and composition of
- “fresh organic soil”. Do you deliver it, or does the “farmer” have to buy it an mix it themselves, Cost? (Space)
- “Rainwater collection, Drip Irrigation, Recycled water” are you a one stop shop, do you expect the farmer to “assemble” the pieces into a working system or do you deliver the working water system , Cost? (Water)
- “Passive solar lightweight greenhouse” Do you have a specific model, does it contravene any city by-laws when placed on a roof, Cost? (Growing Season)
- “Lightweight semi-hydroponic or aeroponic containers” do you have a specific model? Do these containers need to be off the ground, who connects them to the “Rainwater collection, Drip Irrigation, Recycled water”, Cost? (Technology)
- Would the same approach work at ground level.
If yes, how would your costing change to support a street level and gated facility which is about 80 ft by 32 ft. area, which would avoid the need to truck in soil and fertilizer and allow for rehabilitation of an area which has been unusable due to previous land use policy
Climate impact:
How do your calculations change if instead of a root-top implementation it becomes a ground level implementation?
Would your system, implemented at a ground level be able to leverage rainwater captured on a flat roof that would be above the 80 x 32 ft area?
On the roof based system, since the soil is not directly on the roof, will your calculation on Heat loss reduction and cooling requirement reduction hold true?
RE: could they work on the ground?
Hi, thanks for all the questions. I've answered each question you raised in your post:
Capacity and viability:
We do not have an inventory but previous studies estimate Toronto has an available 5000 hectares (8% of the city’s land area) of available space suitable for green roofs (Kaill-Vinish, 2010; Banting et al.). MacRae et al. estimated that ~1200 hectares of rooftop space would be required to provide 10% of the fresh vegetable supply for the city.
Cost and composition:
We have used pure organic compost in our pilot garden. We could source it for the garden installations and provide it, or the owner has the option of finding their own source if they choose. Each unit can hold about 10L of compost, at a cost of about $2.50 per container. There is also a cost for vermiculite ($3/container), and optional mulch covering ($2/container).
We can deliver the working drip irrigation system. Cost depends on the size of the garden but estimated costs for the irrigation lines, drippers and connectors would be about $7 per unit. A timer is $100, an the automatic fertilizer distribution system is $600 (and is optional). A cheaper alternative is to fertilize manually by siphoning the water to the containers; a siphonjet costs $50. Valves and pressure regulators cost about $300. Rainwater collection depends on the garden and whether there is the capability to collect rainwater or not and again, the weight requirements of the garden.
Greenhouse
We have a greenhouse design that we are implementing this year at our pilot garden. The size and style of the greenhouse should not interfere with any city bylaws. The cost is estimated at about $300 - $450 per square meter. We are building a greenhouse that is 200 square feet (~19 m2) at U of T…the estimated cost of this would be about $6000 - $8000. This is competitive with other greenhouse models on the market.
Containers and Irrigation
We have a lightweight semi-hydroponic container that we currently use. It is designed for rooftop use because it is lightweight, but they could absolutely be used on the ground as well. The containers are all interconnected to each other and each container is fed by the drip irrigation system. The drip irrigation system is connected to a tap (or could be hooked up to recycled water or a rainwater capture device).
We have ideas for other containers designs for implementation on rooftops as well. As for aeroponics, we have ideas for designs that could be implemented on rooftops, on the ground and indoors…but we haven’t developed them yet. We require funding to do more research and development to build prototypes and test our designs.
Would the same approach work at ground level. Yes!
Costing change to support a street level and gated facility which is about 80 ft by 32 ft. area, which would avoid the need to truck in soil and fertilizer and allow for rehabilitation of an area which has been unusable due to previous land use policy
Yes, it could be implemented at ground level. 80 x 32 ft = 2560 ft2 = 238 m2. Assuming you put 2 containers per square meter, that’s 476 containers. I’m not sure how you avoid bringing in soil and fertilizer. If the soil on site is not usable because of safety concerns then you have to bring in soil for the containers. If the soil on site is usable, it would make more sense to just implement a standard garden (i.e., no containers). In addition, for any type of container gardening it is generally preferred to use a potting soil or compost, as top soil is dense and leads to compaction issues in the containers. And when you use containers the use of fertilizers is inevitable because of the smaller soil volume. Also, on the roof and on the ground would both be fenced areas and require a water source.
Climate impact:
Rooftop vs. Ground level
At ground level there would not be the same insulative benefits and heating/cooling savings as a rooftop garden. There would, of course, still be emission reductions related to the urban heat island effect, because you are still vegetating the urban landscape, soil carbon capture if organic gardening is implemented, and food miles based on local food production.
Would your system, implemented at a ground level be able to leverage rainwater captured on a flat roof that would be above the 80 x 32 ft area?
Yes, you would still get rainwater capture on the ground, vs. the flat rooftop. However, at ground level there could be interference from overhead structures or vegetation (trees) that would intercept rainwater…whereas the rooftop area is generally completely exposed.
Studies estimate that traditional green roofs divert 60% of stormwater runoff. It is also estimated that a productive container garden would result in the same runoff reduction as the green roof (Kaill-Vinish, 2010). Based on an 80 x 32 ft area with 476 containers, and estimating that half of the area is actually covered in soil and vegetation, we estimate a diversion of xxL of stormwater in Toronto.
Average daily rainfall = 0.01 m X 238 m2 = 2.38 m3 *0.6 = 1.43 m3 (1430 L) average daily stormwater diversion for the given surface area.
On the roof based system, since the soil is not directly on the roof, will your calculation on Heat loss reduction and cooling requirement reduction hold true?
It is likely that the heating and cooling reduction will be less than for a traditional green roof, however how much less is unknown. I’ve tried to address this in other comments as well. No studies have been done on energy savings with respect to a container garden so for now, a green roof is our best guess. If we want to conservatively estimate the difference between a traditional and container system, we could do so based on area of roof covered by soil and vegetation…but this is not ideal because vegetation coverage can vary depending on the types of plants grown. Even so, we would estimate a minimum of 50% of the coverage of a conventional green roof, which would translate to about 50% of the energy savings as a minimum estimate. But there's also the emission reductions associated with organic gardening and local food production that are not provided by a traditional green roof.
Great Answers
Thank you for sharing all those great points about your project.
It is great to see that so much problem solving is happening at U of T
Have you looked at collaborating with Guelph?
Have you looked into the Orion research platform?
Very well implemented
I've had the pleasure of seeing the SkyGarden firsthand and its an inspiring sight; volunteers working together with the common interest of local food production, the serenity in the city provided by the rooftop setting, and direct and indirect greenhouse gas emission reductions. An easily scalable idea with a great potential for engaging people to take interest in food production and sustainability issues. A great idea with a practical, economical implementation scheme.
It works!
I've been lucky enough to participate in the SkyGarden project and to see its success. The SkyGarden has brought together different types of participants who have shared their knowledge to contribute to the amazing growing capacity of the garden. Such an intiative brings gardens to work places and places of learning, thus engaging seasoned gardeners and those wishing to learn about gardening. This leads to more rooftop and backyard gardening in the city as people see the potential to grow more of their own food in the city. In addition, the SkyGarden has initiated relationships with community groups, such as food banks and local food proponents. Scaling up the SkyGarden is an excellent initiative that has the potential for great success by providing city dwellers with an alternative that grants them better food security for the future.
Would love some fresh rooftop veggies
Good use of solar energy and the scarce urban surface area that it hits. Good luck!
This what we should all do to save our future
It is the best project we all should do at our home where we have free space and the space we do not use for our day to day life,and grow plants and vegetables on the roof of our house and also very good use of solar enegy.
by giving and teaching people about the project.
Great Idea!
Love the idea of using unused space for productive uses!
Should be on EVERY rooftop!
I love this idea, and have been a strong supporter for a while now. This model is cost-effective and easy to implement, takes only a small team of dedicated volunteers (or employees, case depending), and can have potentially huge yields. This model can easily be scaled up (to as many containers and lines as will fit on a given rooftop, drip irrigation, automatic fertilizer dosing, landscaping to integrate the container systems into an attractive greenroof design, etc) or down (just a few containers, hand-watered and manually fertilized) to fit on any rooftop from a private home to a huge institution or business, on virtually any budget. This type of garden can easily be tailored to fit a business, with employees charged with maintenance, or a non-profit, with volunteers and educational use of the space, or even a private home where backyard gardening is either not feasible or just not enough!
I live in an 18th floor apartment looking out over most of the downtown core, and I often imagine a day when Sky Garden style rooftop vegetable farms will replace all of the bare concrete slab rooftops I see today. I can't wait!
More Sky Gardens, on more rooftops, in more cities, with more people involved, and more food consumed by urban residents coming directly from our own rooftops!
Great idea!
Making gardens lightweight would definitely make rooftop gardens more viable.
How feasible is this for the everyday person to use? For apartments, people usually don't own the roof. For homes, they can't access the roof.
RE: Great idea!
For apartments, we could scale down for use on a balcony. Alternatively, a good idea is the apartment or condo building implementing a larger garden on site as an amenity for residents.
As for home owners, access may be an issue. I've addressed that in some other comments, but agreed it could be problematic. But a lot of home owners also have balconies and patios that could be used - or likely they have yard space that could be used for conventional gardening.
And finally, some of the most promising candidates are community groups, restaurants, schools, that generally have a larger and more accessible rooftop area and the opportunity to engage a community.
Innovative and Smart!
It is a good idea however the feasibility of it's success on each and every rooftop should be well evaluated before implementing. It should not lead to seepages which will damage the whole building in the long run.
By checking the feasibility of the practical applicability and by better marketing.
Great idea!
There is a great need for lightweight methods of growing food on rooftops. This is a great way of dealing with food security by converting unused rooftops into productive spaces. There is a huge amount of area that can be used in this way. Nice work and I hope you can bring this timely idea to life!
Ideally, the rooftop garden containers can be made out of recycled content material. Is it possible to combine it with an irrigation system as well?
Irrigation - Yes!
It is absolutely possible (and recommended, for large-scale gardens) to combine a system like this with drip irrigation. Our pilot rooftop garden has about 100 containers and a drip irrigation system, on a timer, that includes the capability of regularly dosing liquid fertilizers into the water supply. A garden with this many containers would take a many people a long while to manually water in the height of the summer.
The nice thing about a system like this coupled with a drip irrigation system is that the containers are all networked together, so if some crops use more water than others (tomatoes for example get very, very thirsty) then the water in the reservoirs in each container shifts back and forth between containers with more and less water, so (with proper setup of the irrigation system), no plants will be waterlogged and damaged by root rot and, at the same time, none will dry out and wilt.
I like the applicability to
I like the applicability to so many spaces and the flexibility of small-ish containers
I would like to see a rain barrel component or simple ability to connect to rain barrels included
Rain barrels
Hi, Thanks for the comment and for mentioning rain barrels. This is something we have thought about and could definitely include in some projects. It depends on the site though. If your rooftop garden is the highest surface, then there is nowhere to collect rainwater from.
If we can ensure good coverage of the roof surface then we can divert a lot of storm water directly to the garden though direct infiltration to soil and plant surfaces. Each container has a water reservoir in the bottom, so can hold excess rainwater in case of a storm.
Make it mainstream
Benefits: Energy efficiency due to shorter food transport and building insulation, stormwater runoff effects, improved air quality, reduces 'urban heat island' effect, provides habitat for the birds and the bees AND makes the city beautiful and edible!
How do you make the incentives tangible and accessible to the public? How do you reach the maintstream grocery store goers and make them feel connected to the projects and willing to invest in it?
I support Roof Top Gardens!
I think it is an amazing idea to help cities produce their own food. It helps in maintaing the biological environment in stability. Not only it is good for people to eat good anf fresh food it also important for them to maintain the enironment, and roof top gardens are sure a win at that.
This proposal needs a lot of resources as in to grow people need roofs and other things to implement. Also it is a long process. People cannot wait till the time the fruits and vegetables grow. This proposal needs to have a more realistic approach towards the cities ang big town where most of the people live in apartments.
Resources, waiting for harvest.
I'm not sure what you mean about not being able to wait for fruits and vegetables to grow. It doesn't take long to go from a tomato seedling in the spring to lots and lots of fresh tomatoes in the summer. And I'm not sure what the alternative would be, to waiting for vegetables to grow... That's just a reality of farming/gardening, under any circumstances.
With regards to requiring a lot of resources - gardens like this actually don't cost a whole lot to set up, and the great thing is they're easily scalable, from just a few containers on a residential rooftop, watered by hand, to a huge network of containers on a drip irrigation system. And rooftops are definitely not in short supply, especially considering that the light-weight nature of these gardens makes them suitable to almost any rooftop that is safe to be walking on in the first place - the only major change most rooftops would need is a railing around the garden space.
Resources, waiting for harvest
And just to add to Matt's point, if people want access to food year-round it is possible through season extension techniques. The greenhouse allows continued harvest of cool-weather vegetables and our partner organization, FWI, teaches skills related to preserving the harvest so it can be enjoyed throughout the winter months.
great idae to save nature and resources
great one to make our own food and resources and feed ownself and producing on our own for our people.
by sharing own exprience to others and by giving inspiration to others
effective utilization of space..
This proposal of roof top gardening is a an intersting proposal. it makes use of the roof tops in a constructive manner which otherwise would be a sheer wastage. Moreover it makes the individuals atleast self sustainable in respect of green vegetables. it surely will increase the the healthy eating habit of the individuals.
it can be improved with the use of proper training to the individuals, so that they don't create a mess over there roof tops.
Rooftops effective Utilization
This is a great idea as it uses the best allocation of rooftops and resourses.People will start taking more interest in managing their rooftops as it is cost effective and less labour is used for the setup of the lightweight rooftops.
On the other hand it is only good for houses it is more sophisticated in case of appartments so more efforts and space will be needed.
New condominiums should be built with more space and stable rooftops so as it can be easily accessible for the setup of rooftops...
Innovative Biological concept
This is a great concept keeping in mind the need of going green in big cities. It also helps them in self sustainable growth and maintaining the green house gases. It is a concept that is beneficial at multi levels.
This proposal can be improved by allocating proper resources and providing proper and practical knowledge to the urban residents by organizing free seminars.
Workshops
We do actually hold free workshops on urban gardening, using the pilot rooftop garden as a teaching space. If you're interesting, you should send an email to either [email protected] or [email protected] to be included in email alerts about upcoming workshops.
Tied off?
I would think everyone using these so called gardens would need to be properly tied off to the roof, like construction workers.
Greenathon..!!! Why Not?
The primary strength of this proposal is the mass acceptance that it might receive from the urban citizens and restaurants as this concept will clearly make a better and eco friendly use of the spaces. It will also make them self reliant in terms of growing vegetables and fruits.
To me personally, there is no concrete weakness in this project and it must be implemented for varied welfare reasons.
This proposal can be implemented when people are patient and practical enough to implement this proposal and also wait for the changes to take place in a long run. Households need to be educated regarding this issue on a professional as well as personal basis.
the main strength of these
the main strength of these propsal is that it will save money of an individual and also people will have organic vegetables to eat and also it will be helpful to enviroment.
it can improved by preventing it from birds by taking proper precautions for that.
Birds aren't really a problem.
Birds haven't really been a problem at all, actually. And what's more, you avoid to a large extent a number of ground-level nuisances, like raccoons, squirrels, rabbits, etc, as well as limiting soil-born pathogens.
Innovative access to Veggies
Better for wildlife, Better for soil,Optimium Utilization of resources, good for animal reproduction, helps to fight against diseases, highly nutritional, Protects climate, Human friendly and environmental friendly.
Access to fresh vegetables anytime. Produces higher yields in drought conditions. Innovative to start a new venture on organic farming business.
Awareness, advantages and importance of organic farming should be shared to gain more knowledge on it.
Awareness
Agreed! Awareness about the health and environmental benefits of organic gardening are important. This is a comment that is popping up over and over. There are a lot of great organizations working towards this goal, including our partner organization, the Food and Water Institute, and several other organizations in this competition.
A brilliant and under-rated
A brilliant and under-rated idea.
Well thought out, a few additional observations
The GHG benefits of organic vegetable production compared to conventional are not as uniformly positive as the Rodale study you cite (which deals with field crops). Much depends on what kind of vegetable production scenario you're comparing to. Similarly, the food miles reductions are dependent on the comparison. If somone is already buying locally, the benefits will be modest and to some extent we penalize domestic farmers who are already struggling. But if the rooftop production replaces imports from California and Florida, the benefits are more substantial. Season extension is very helpful in this regard, but it's also important to examine where there's sufficent light in winter to grow greens. Some studies show that in low light conditions, leafy greens will produce excessive levels of nitrate in the tissue, not a good thing. Consequently, production in jan/feb may not be a good idea.
A few additional observations
One of the benefits of rooftop gardening is it teaches people the importance of local, in season food...both in terms of health and environmental benefits, but also in terms of quality and taste. So we think that growing more food in the city will also help to encourage people to buy produce from local suppliers as well.
As for the nitrates, this is typically a phenomenon seen when using nitrate fertilizers. Since we use organic fertilizers in our gardens, usually made from compost, this shouldn't be an issue. Neither should lower light conditions in winter. There is still adequate light to grow the leafy greens and cool weather crops.
Great Idea
This idea sounds great not only because it will contributes to the environment but also make roof looks attractive and appealing. The strengths that I can see are that the results that can be obtained on rooftop vegetable gardens can be the same as expected from the results being obtained from the trees or the farms. It is light weighted which sounds of good quality as being seen from the implementation point of view by buyer.
This idea needs the expertise for the better implementation and also as far as maintainence is concerned. It needs the involment of people all together and also the ways with which maximum number of people can be encouraged for rooftop vegetable gardening. Overall, it is a very good proposal.
Amazing initiation.
This idea is very very amazing. It will help to serve nutritios food to poeple and will not affect climate also.
Main strength is it will give the feel of personal garden also.
people will think about climate also.
To be on Top start growing Rooftop
The concept of roof top gardening is not new but has not spread in the environment so as to be proven as successful, In Singapore due to shortage of land this remains the major source of vegetation other than imports. This not only provide with food but looks beautiful. As in Canada it snows for almost 6 months making natural environment unsuitable for vegetation this kind of practice lets Canada to grow its own products and makes it look beautiful too. There is one already in Vancouver British Colombia
This proposal to be a success must cost effective as constructed land generates lot revenue and if setting up of such rooftop vegetation is a costly affair then it will be substituted with import of products. The more of research and development is required so as to make the project cost efficient and yet yield a profitable yield.
This model is actually really
This model is actually really cost effective. I work on this project and we did some number-crunching to make a case to Toronto city hall regarding how grant money for projects like this is extremely well spent. Here are some of the numbers, to put it in perspective:
- Our pilot garden cost about $5,000 to set up.
- It generates about $2,700 worth of organic produce per season (based on costs at local markets).
- Year to year costs are fairly negligible since we save seeds and start our own seedlings in the spring with the help of volunteers.
- That means it will pay for itself in just two seasons.
- The equipment has a lifespan of 20-30 years.
- This means that a garden like the one we've set up could generation $50-80k worth of harvest before requiring replacement.
Considering all of that, this sort of garden is extremely cost-effective and businesses, condo developments, etc. who are conscientious of environmental and food security issues would be hard-pressed to find a better "bang for their buck" than something like this.
I think the strengh of this
I think the strengh of this project is that it will promote local food consumption, reduce food miles, and help city dwellers to be better educated and more connected to their food source. It might also help city dwellers to better understand and respect farmers, since by having the opportunity to grow their own food they will better understand the challenges and rewards of producing food.
very nice idea
to get things to grow on the roof top is n exceelent idea especially for people who dont have backyard. we can grow fresh stuff and dont have to worry about buying vegitables. more and more land is getting under construction so it will show us some new ways of cultivation.
cultivation on rooftops should include things that should have utility in daily basis and not just growing anything
An old idea and an introduction to TO! Way to go!
This worked wonderfully in other parts of the world, it's time TO gets moving on it.
Getting both rentals and the condo market on board.
Rentals and Condos
Yes, we're working on it! It's a great idea for apartment buildings and condos as an incentive for renters and buyers. Especially if the residents are given their own garden plot in the building.
This is a fantastic proposal.
Very impressive
Great!
This propsal is excellend and will help many future generations ! Brilliant!
Simply Rocking
Great Initiative
needs collabaration
strength is that it serves
strength is that it serves individual daily needs of the vegetables and fruits.
it can be a hygenic proposal.
it can be improved by taking the appropiate measures to grow vegetables and fruits on top.....
Community building
I have been a long time fan of rooftop gardening and really like this project.
I could see this being used on school rooftops by the surrounding community. Perhaps fees to participate could benefit the schools and the students could also participate while learning valuable lessons in doing so.
Schools, Community Rooftop Gardens
I agree, schools would be particularly ideal sites for gardens such as these. Unfortunately there's a fair bit of red tape to go through before getting students up on rooftops... But provided there was a sufficient railing and safety requirements were met I think it would be great. Get kids eating healthier foods and learning about how to grow them in the process!
I also really like the idea of community rooftop gardens, either on public buildings where people could pay some kind of membership for a "plot" on the roof, or on condo or apartment buildings for the residents to use. Many apartment residents are seniors who would probably love the opportunity to garden in spite of apartment life. These types of gardens could easily help to meet the demand in cities for extremely limited community garden space.
Awesome
I think that taking responsibility for your own consumption is a great idea!
I am wondering though if you have done any research or collaboration as to the potential toxicology involved in growing food in an urban city.
soil contamination
Good question. Growing on rooftops and producing our own compost there would avoid the potential soil contamination problems sometimes encountered on the ground in a city.
soil contamination
Also, to add to Erika's point, the rooftop environment is less exposed to direct air pollutants, like car exhaust, than gardens on the ground.
In fact, our garden at U of T is used as the control plot for a study of urban air contaminants and the accumulation in agricultural soil and plant tissues.
More O2
More O2
Great stuff
Nothing wrong with adding to the world and trying to make it a better place. This idea is good for the environment and safer. Go get em guys!!!
Very effective technology
This is a very powerful idea, especially when combined with other technologies.
Very effective technology
This is a very powerful idea, especially when combined with other technologies.
amazing use of space
Wonderful way to grow locally using spaces all ready in existance.
Would love to see it happen
I always love seeing/hearing about roof top gardens. Although they always seem to need a lot of persistant work. It could be hard to maintain them if it is only volunteers working on them.
Exciting idea!
Wouldn't it be great if one day, you could go to the top of the CN Tower, look across the city, and see food growing on rooftops in every neighbourhood? A lovely dream. Good luck with this venture!
How can this venture be inclusive of members of the community with mobility issues who can't physically access their roof? I've been to the apiary at U of T, but only because I'm able-bodied and can climb that crazy ladder into the boiler room that lets out onto the Trinity College roof.
Accessibility
Hi AJ, it is definitely possible to implement a rooftop garden that is accessible. There are examples of accessible gardens in the city (like the Metro Central YMCA green roof and Access Point on the Danforth). It just takes more planning.
Great idea, but tackle regulation barriers first
I love this idea. but so many commentators have said it's too hard to get to their roofs because of municipal regulations saying 'no ladders'.
Put together a strategy to tackle the municipal regulations first, then this idea might work.
Regulation Barriers
It's not even that ladders are not allowed, but really they are not a good idea and it would be too difficult to move equipment up and down a ladder from the rooftop. But rooftop access depends on the design of the home. Some homes have access to rooftop spaces through staircases, doors, and windows. Or they might have patios or terraces. So the idea will still work for homes, but also for larger buildings, restaurants, community groups, etc. that most likely already have stair access to the rooftop.
Simple tech, but where are the people?
This proposal focuses on a solid set of straightforward solutions to at least some of the technical issues of roof-top gardens. especially weight and water use and waste. The engineering issues of extra dead loads have been acknowledged, but from my experience the issues of live loading (snow and wind) are equally significant. I.e., the additional structures on the roof create additional snow and wind loading, normally beyond minimal design limits.
Perhaps a larger issue - essentially unaddressed - is the question of social sustainability. Even if the technical issues are resolved (which will be unique per site - there's no cookie cutter here), the questions of ownership and operations are far larger with gardens, no matter where they are sited.
How can each major roof top garden site begin with and be sustained by a group of people who are passionate about creating their garden? Will they include, or have access to, the support of a team of community development facilitators, who can help mobilize, organize and structure this project for the long term? Each roof top has an owner, or set of owners? How does the garden fit into ownership? Do the owners become gardeners? Do outside gardeners organize and lease the roof? What are the possible models for ownership? Community-based? Profit? Non-profit? Co-op?
The technology is simple; people and how they self-organize as gardeners - that's the killer assumption. This proposal needs some serious social and community modelling work - how are these rooftop gardens working in 5 and 10 years? The worst advertisement for roof-top gardens would be a crop of abandoned, lightweight green houses across the city's rooftops, frames rusting and plastic sheets flapping in the wind...
Technologies and Methodologies for community development
It is great that you are all working towards solving the issues of gardens and greenhouses on roofs.
Has the team looked at the logistics of removing food from the roofs?
cranes, Elevators, chutes?
What about safety and zoning bylaws?
Do you think Toronto will lead the way in green roof infostructure?
Community modeling could grow from Co-operative development models like
Grow Local Organic
Organic Food Strategy for Ontario: Value-added Processing
Written By Russ Christianson and Mary Lou Morgan
http://www.organicagcentre.ca/Docs/GrowLocalOrganic_wwf_Oct-07.pdf
looking to the future of food production in cities, how can we benefit from developing community franchise food co-ops with light weight greenhouses as the technology part of the cycle.
Who are your Non-profit supporters?
Where are the people?
I would imagine that anyone who would buy a rooftop garden system would do so because they are passionate about creating their garden. As for participation from the community, it depends on who owns or commissions the installation. It is up to them if the public, or the building residents, or workers, or whoever is in the affiliated community, will be involved and in what capacity (volunteer, co-op, profit, etc. are all options). And my experience working with urban agriculture for the past 7 years is that it is easy to engage the community if the project is made available to them. There will always be people who want to garden if they are given the space.
And if it really isn't working in 5 or 10 years, or however long...it's not permanent. It can be sold, donated, moved to another location where it could thrive.
looks like a great project
looks like a great project
Challenges
What do you think are the greatest challenges retrofitting existing buildings?
Do aging buildings and backdated building codes affect your proposal? Retrofit is another term for expensive in the construction world
Would love to hear some feed back
good idea
Strength: maximizing empty space for much-needed green ideas, helps reduce building heat/cooling loss, can be community oriented
Weakness: need non-profit or multi-residential building partners as this project appears to support just one for-profit business and seems designed mainly to help that business grow. Funding should be for a broader positive impact.
Partners
This venture is in collaboration with The Food and Water Institute, a Canadian registered charity. We also work with other urban agriculture related groups as well as community groups to spread this concept and general awareness about growing food in the city.
The ClimateSpark Social Venture Challenge is a project of:
Our sponsors:
Great idea!
Rooftop gardening is an idea that's time has come. We need to start eating locally and cities need to start producing some of their own food, both to help the environment and to increase food security. What better way to make affordable, organic and locally grown produce available in cities than to grow it in our neighborhoods?
I would like to see this project implemented on a larger scale in cities across the country.