In my opinion as the Green Roof Patroller, the best green roof solution can only come from well-educated practitioners with a very long experience in selected horticultural and landscaping fields. Over the many decades, Green Roofs have been developed from a mixture of high performance natural materials to a combination of engineered elements with natural components.
Since North America was introduced to modern Green Roof technology much later than Europe, I believe only a few people understand the real basics and the evolution of this amazing landscaping/ horticultural practice on ground-remote locations.
Without understanding the basics, the North American Green Roof market is still like a kid who learns by trial and error – on the back and costs of building owners. One problem is that every few months “new,” “revolutionary,” and “optimized” Green Roof systems are introduced. Made of all kinds of materials that may sound good, many hardly withstand the biological activity of plants or the harsh environment on the roof for as long as the structure lasts.
Something that may have been tested by NASA or firefighters isn’t automatically good for the plants or the environment. The engineers or technicians behind such reinventions of the wheel might have fancy degrees. However, many have hardly installed their own developments with their own hands on a large scale.
Additionally, they never evaluated their inventions or innovation over a long enough time (more than 5 or 10 years) before making them available for the market. I have seen people coming into this industry with a big bang and quietly leaving after a while to move up in the hierarchy of a different industry – to do the same there?
All of a sudden, the kid falls into the water well (a/k/a the Green Roof is not performing), then the building owners call for practitioners who are supposed to fix the engineers’ problems. Building owners don’t usually call the original engineers or technicians because they can be vain.
And, when later problems or questions arise from the building owner, the engineers behind the design of the green roof don’t necessarily feel responsible anymore. Perhaps they don’t always know the answers without Google, and these are hardly right. In some cases they call a practitioner later; and even then, they don’t always provide the entire picture.
The beauty of engineering – a squared box doesn’t follow a radius.
Engineers are typically not seeking for answers that discredit their efforts. However, they try to suck out every piece of information they can get from practitioners and simultaneously avoid valuing the source because of being afraid of scratches to their polished image.
An additional problem is that most engineers (even at universities) are on the payroll of large corporations that are pressured to develop profit-maximizing solutions. These solutions are typically against the needs of plants – because plants don’t care about money and the stock market.
Plants are “only” the key player on green roofs. No happy plants = no Green Roof = no happy client.
I estimate that around 50%-60% of all Green Roofs in North America are underperforming, failing, or have been renovated, replaced, or will be going under a major renovation soon. For Germany I would estimate this number at around 5%. At the same time, in Europe an extensive Green Roof costs around $5/sf and in the US closer to $20/sf.
1. No solid, full time practical training over more than two years before getting a professional in this field.
2. Students are not being paid during practical education – they actually have to pay a few 1,000 bucks to get a certification, like buying a certificate or a title at Walmart.
3. No innovative and large scale research over 5-10 years. Just baby step copies and mail stamp-size research (typical research areas in Europe are 10-50 times bigger than in the US).
4. Green Roof contracts are coupled with roofing contracts (it is like buying a dryer only in combination with a fridge).
5. Low roofing quality, materials and/or inverted roof membrane assemblies (IRMA).
6. Repurposing materials that were never engineered for green roofs (e.g., in my opinion, there is no American-made drainage board that would meet my criteria and the full needs for plants).
7. Worthless single source warranties. If you choose your own microwave, you don’t get a warranty on the fridge.
8. Greed for quick cash and/or fame.
9. Not understanding the big difference within the horticultural trades (a carrot grower is not automatically a green roof expert and a beekeeper doesn’t understands all plants).
10. Huge deficit in experienced and reliable hands-on installers and maintenance for Green Roofs.
11. Often, hands-on installers/practitioners are treated dismissively from architects, GCs (general contractors), roofing companies, or engineers.
Practitioners are not Blue Collar workers, they are not White Collar workers. We are Green Collar workers who stand above the traditional collar thinking and who have had the patience to monitor this unique living environment for decades to learn how to go beyond what is written in books or on the internet.
All the above problems have a great potential to damage the Green Roof business in the long term. Building owners don’t want to be ripped off and each project that causes problems will change their opinion about Green Roofs in general. While many building owners don’t want to commit to owning up to a problem on their green roof, others will spread the word among other building owners.
Ultimately, all the nice colorful brochures and great write-ups from environmental associations won’t help to change the opinion of a dissatisfied building owner, nor will it change the quality of Green Roofs.
As a practitioner I approach things very practically:
If I want a good loaf of bread, I am simply not going to the butcher. So why do you let the butcher engineer your Green Roof?
~ Jörg Breuning, the Green Roof Patroller
An Exceptional Green Roof
After more than half a century in temporary quarters, Sufism Reoriented now has a permanent home in Walnut Creek, California. Designed under the guidance of Murshida Carol Weyland Conner by the distinguished architectural firm of Philip Johnson Alan Ritchie, the new sanctuary is set among serene gardens on three acres of land in a suburban neighborhood about twenty-five miles east of San Francisco.
Alan Ritchie’s design perfectly realized Murshida Carol Weyland Conner's vision. Brought to fruition by the Architect of Record, Soga + Associates Architect Inc, this beautiful design is to endure for over 700 years. The building is innovative in many ways, from its curved marble cladding from Carrera, Italy, to its climate control with state-of-art air filtering systems, to its Green Roof composition with 100% recycled Foam Glass Gravel engineered by Jorg Breuning , Owner of Green Roof Service LLC , to its storm water management with rain harvesting features to retain the entire annual rainfall, to its 33 feet tall hollow bronze sculpture with seismic base isolators and acrylic butterflies, standing inside of a 3-story tall room with curved glass guardrails.
With highly experienced architectural services and project management by Clement T. Soga, Soga + Associates Architects Inc, the Sanctuary’s construction began on May 24, 2012 and its Ribbon Cutting ceremony was held on February 24, 2017.
Green Roof Service LLC – Green Roof Technology worked hand in hand with Sufism Reoriented, Soga + Associates Architects Inc, and SWA Group Landscape Architecture to create a Green Roof solution that perfectly mimics the natural soil horizons with materials that will last thousands of years without compromising or limiting healthy growth of any vegetation at any time. Jensen Landscape carefully implemented the details and specifications of this new type of Green Roof under the direction of Jorg Breuning. It is the first Green Roof in North America that utilizes Foam Glass Gravel made of 100% recycled glass on a large scale. The ultra-lightweight material performs as a drainage and retention layer combined with outstanding structural capacities. Foam Glass Gravel is produced in the USA and in Germany according to the strict specifications of Green Roof Service LLC - Green Roof Technology.
27th February 2017
World’s First Modular Green Roof System
Green Roof Professionals around the globe often wonder or speculate how and when the commercial modern Green Roof industry really took off. There are many opinions and alternative facts out there but only a few really know that the hot spots with patents were in Basel Switzerland and in Stuttgart Germany for seamless or wall-to-wall Green Roof systems.
The World’s first modular (or tray) system has been developed in Stuttgart by Brecht and Hämmerle, mainly known as the Brecht System (if one doesn’t consider terracotta pots on roofs as a modular system).
The Brecht System was a basic polystyrene box with a three-layer Green Roof system. The system was available in extensive, semi- intensive and intensive planting depth. With this simple three-layer system the inventor combined many benefits in one box. All systems had a water reservoir for maximum water retention – more than any other Tray system currently on the market and more than any fabrics, foams or mineral wools, and the boxes contained standard nursery soil for a healthy fast growth and to lower costs.
There were different options for covering the less attractive boxes, with either wood or metal (aluminum). Today we call these frames around the boxes: Edging.
Based on the polystyrene, the boxes were very lightweight and easy to install. Actually, they fitted into each other to create different heights and different planting depths. I would describe them as a Modular –LEGO-like planting system.
Unfortunately, any polystyrene as a limited lifespan when exposed to UV or biological activity and so many of these roof gardens had problems after 5-10 years. Further, many of the plants rooted out of the boxes (drainage holes) and penetrated the waterproofing.
Around 1992 the last Brecht System was removed and replaced by wall-to-wall or seamless Green Roof systems. All of these Green Roofs are still existing - if the building still exists.
The Brecht Modular Green Roofs system had also other issues that are similar to the currently existing systems. However, nowadays the tray systems use metal, other plastics, and mainly with irrigation systems. This makes them last longer, but as often only delays the point of failure. The roots of plants and the biological activity on healthy Green Roofs are often underestimated as well as the functional lifespan of foams, polystyrene drainage mats, and mineral wool products.
Norwegian Green Roof Log Cabins in the USA
Around 50 years ago there was trend in the USA of having Norwegian Log Cabins as a second home.
Green Roofs and Fireworks
Practically all dry organic materials are combustible at relative low temperatures. Roof shingles or many waterproofing membranes on roofs are typically petroleum-based products (including Asphalt) and there is hardly any difference to dry organic materials. Some products are equipped with chemical fire retardants that could decrease the risk of spreading fire, unfortunately not the risk of leaks cause by heat and impact.
The living vegetation of fully functional and well-engineered green roofs contains moisture and most plants (especially succulent plants on large extensive green roofs) have a fraction of the energetic potential comparing to all other components used in a building. The green roof growing media (soil for the green roof plants) is a blend of different mineral components with an organic content of typically less that 15%. It is practically impossible to set this material on fire – even when the natural moisture content is not considered.
Fires or leaks on non-vegetated roofs caused by consumer or display fireworks could have been prevented if the building would have had a fully functional green roof without mono-culture vegetation, or if conventional roofs would be well-maintained (regular removing of organic debris from the roof and gutters).
Certainly a fire is the worst-case scenario; however in most cases smoldering firework parts (and cigarettes) are only causing leaks on unprotected roofs that are discovered much later and relate to costly repair. Roof warranties typically don't cover any sort of mechanical impact and they are -again- worthless. See blog post from 2014.
Any sort of fireworks damages or many other mechanical impacts are unknown on functional green roofs. Green roofs prevent leaks or even a fire and so it is the best payback is right there.
Nature is (literally) so cool.
Happy New Year!
Urban Planning in North America
Most American Cities like to have a diverse, sustainable, and thriving city of neighborhoods as the economic and cultural driver for the region.
In reality, these urban planners fall for nicely presented prestige projects that maybe have some green elements like bicycle storage, a solar panel, or living elements like a little green wall in the entrance area or roof terrace with some tomato plants. A little decoration of green is always trendy – whether it remains green or not. Important seems that the building is shiny, the investors and tenants have good names, and that it increases the prestige level of the city.
Urban planning in North America has hardly anything to do with long-term perspectives, environmental, people, or social aspects. “Urban” planning does not go further than maybe two or 3 blocks in a city. North America is a big continent with many tunnel-view urban planners, and since many of these planners have not much to do, they write daily blogs about “great ideas” of new ways for urban developments. It seems they write a lot and they do not do much.
In Europe, urban planning is almost on a helicopter- view basis, long-term with environmental and social aspects. Europe’s great urban planning doesn’t stop at the city or county line and it greatly reduces destructive urban sprawl. Being an urban planner in Europe is a tough job – they have no time to play on the internet posting great ideas. They just do it.
The picture below shows a neighborhood in Munich, Germany from google Earth. The development of this area started in 1994 and it is still going on. Developing an area like that over 20 years required a comprehensive urban planning long ago and with on single goal: minimize the environmental footprint.
1. The area is connected to a large park with sport arena, pools, gyms, and recreational facilities including beer gardens.
2. The community garden on the north allows people to grow their own flowers and vegetable.
3. Most roofs are covered with green roofs, some are used of recreation or growing flowers and food. Most buildings have balconies where plants grow up (extensive green walls).
4. Open space for socializing, playing games, walking dogs. Typically these areas are above underground parking garages.
5. Solar Garden Roof that combine solar with green roofs to max-out the environmental benefits.
6. Houses are entirely covered with PV.
All buildings have very easy access to a dense public transportation network and many office buildings can be reached within walking distance or by bicycle.
Does this ever happen in North America?
While in North America the average size of Green Roof is around 8,000sf this size would be considered a small size Green Roof in Germany. The average size in Germany is likely over 25,000 sf and the amount of Green Roofs build every year is probably 10 times higher.
Despite higher energy costs, the costs for the installation are lower in Germany because they build them in less than the half time, with fewer people, with hardly any middle men, without pre-planted plastic boxes and without consistently reinventing the wheel. They don’t try to sell warranties – they are actually installing Green Roofs. They also spend no or less time posting their projects on all social platforms and don’t need to say this is the biggest, nicest, most divers, highest or any other superlatives.
They just do it because they understood the environmental and social benefits of Green Roof mass production instead of trying to grow one carrot in a city for millions of people just to be on TV. Green Roofs in Germany are done for everybody vs. in North America it is often done for personal vanity.
16 years of North American Green Roof industry and still researching? When does North America think big?