Search
Back to Home Page
Home   |   Contact Us Ph: 443-345-1578

Green Roof Technology Blog

Rooftop Farming an Environmental Nightmare

Green Team at Green Roof Technology, - Tuesday, June 04, 2013

By: Jörg Breuning

Companies spend millions of dollars on creating rooftop farms to demonstrate how "green" they are. There is no doubt advertising with living green is a good idea because it makes the customers believe that the company practices environmental leadership.

However, the reality looks very differently.

Recently a food company started a huge campaign promoting their rooftop farm (and their green leadership) by opening a 17,000 square foot rooftop farm on the East Coast.They were optimistic that they could grow 10,000 pounds of produce during the short growing season. This is approximately 25% over the average vegetable and berry crop yields estimated for New England on the ground during a good year, based on traditional irrigated farmland.

Since environmental conditions on rooftops are more extreme, achieving this goal seems ambitious and will require higher amounts of water and fertilizer. With more moisture in green roof soil the main benefit of green roofs (stormwater retention) is sacrificed and the run-off will most likely now contain more nutrients than in the run-off from traditional farms. Nutrients are already the number one pollutant in our waterways.

Based on these harsh environmental conditions growing crops on rooftops will be more labor intensive.

A 17,000 square foot rooftop farm requires approximately 300 tons of engineered growing media (soil) or 672,000 pounds in order to grow an average of 8,000 pounds of produce a year. In other words, it takes more than 80 years to grow the equivalent crop weight that was transported up onto the roof in the first place. This does not include the tons of water, fertilizer or structural support for the building that has to be shipped to the city and hoisted up on to the roof to start and maintain the garden.

Roof top farms ultimately increase the shipping (costs) of goods into cities. Shipping produce from a farm located on the ground is cheaper and more efficient because everything necessary to sustain the farm is already at hand. The food from rooftop farms is being transported a shorter distance creating a false sense of environmental responsibility. When in reality, the amount of materials essential to implement and maintain a rooftop farm outweighs the good in this situation.

Consider this: every person consumes 200-400 pounds of produce in a year (Profiling Food Consumption in America in 2000, Agricultural Fact Book) and an average of 8,000 pounds feeds around 20-40 people and requires at least one full-time, skilled farmer.

On a traditional field, one farmer can easily manage a 10-20 times larger area with a higher yield per acre using organic principals, which are not even discussed with most roof top farms.

Buyers of food from companies with rooftop farms are misled by advertising and are paying more for their goods while supporting a trend known as Greenwashing.

Jörg Breuning welcomes people who want to learn from decades of green roof experience - askjorg@greenrooftechnology.com

 


First Steps to Planning a Green Roof

Green Team at Green Roof Technology, - Tuesday, April 23, 2013

 By: Samantha Yurek

Happy Earth Week! Hopefully everyone has taken some time out of their busy lives to lend a hand to our beautiful planet we inhabit. Whether it is picking up some litter, planting a tree or deciding to go all out and look into acquiring a green roof! Here are a few things you should have a good idea of before you leap into the planning process.

1. How sturdy is your roof?  Adding growing media and plants to your rooftop adds weight to your structure. Make sure your roof can handle some extra weight first. Find out the materials and structure of your building.

2. Is your roof sloped?  A slight slope is perfectly fine, but anything steeper than 15 degrees, the roof might become a slide for the plants without additional constructive design.

3. How much are you willing to spend?  Implementing a green roof is an investment for the future. Simple extensive vegetated roofs usually cost around $10-$15 a square foot (pre-grown planter boxes or modular systems are more expensive). Many local programs will help pay for green infrastructure, based on the environmental benefits. 

4. What type of green roof are you looking for?  A simple meadow-like area, not accessible and mainly for the environmental benefits (extensive) or an intensive roof, complete with recreational room and the potential for larger plants such as trees.

5. How are the sunlight conditions?  The majority of green roof plants enjoy direct sunlight to flourish. If the building is situated in a heavily shade area, the green roof plant selection becomes limited.

6. Do you want an integrated solar green roof?  The Sun-Root™ System is the newest of technologies, a fully integrated system and an ideal symbiosis of PV panels and an extensive green roof. It is easy to install and will not penetrate the roof. The entire system has the potential to pay back within 5 years and also meets stormwater requirements in all cities of North America.

 

Do your homework first before deciding on a green roof, our website is a great starting point to increase your green roof knowledge. If you're interested in a green roof or have any questions, please don't hesitate to contact us, we would be happy to help you get started today!

Extensive verses Intensive - Which Would You Choose?

Green Team at Green Roof Technology, - Tuesday, April 16, 2013

By: Samantha Yurek 

A lot of thought goes into the design process when starting a green roof project. One of the biggest questions involves the type of green roof you want; extensive or intensive? This decision will dictate everything that will need to happen for your green roof to become a success. Let us take a quick look at the differences between intensive and extensive green roofs.


Extensive Green Roof: Swarthmore College of PA, Photo Credit: Green Roof Technology

Extensive green roofs are considered the simpler version because the roof structure is usually equipped to withstand the little bit of extra weight. With only a maximum of 6" of growing media and mostly ground cover covering plants, and extensive roof is certainly of a lower profile. The plants consist mainly of sedums and other succulents, herbs, grasses, mosses and low-growing perennials. An extensive roof is mainly for environmental benefits and and occasionally accessible to the public. Extensive green roofs can be excellent combined with Solar panels what increases the environmental benefits and increases return of investment substantially.


Intensive Green Roof: The Ledge Restaurant in Boston, Photo Credit: High View Creations

Intensive green roofs on the other hand can become quite extravagant. The roof must be very sturdy in order to hold foot traffic, deeper growing media and larger plants. The plants found on an intensive green roof range from shrubs and perennials to larger trees. Accents such as ponds and recreational spaces are a possibility. An intensive green roof is a busy and more expensive system with more potential for greater designs and biodiversity.


Follow Us!

RSSGreen Roof Tech Blog
RSSGreen Roof Plant Blog


Recent Posts


Tags


Archive

Latest Blog Posts
  1. Celebration 20 years of Integrated Green Infrastructure Green Team at Green Roof Technology, 12-Jul-2018
  2. Power Plant and Green Roof Green Team at Green Roof Technology, 10-Jul-2018
Facebook   Twitter   LinkedIn   Google+   YouTube
Go To Resources Page