On a recent visit to the Fjords of Norway, the ancient home of the Troll, I was struck by what I saw protruding from many of the rooftops of the local homes. It seemed to me that the houses had grown Troll hair! Could it be that Trolls had left the mountains and dark forests of Norway and started building subdivisions? Further investigation was required.
A closer look revealed that what I had at first taken to be Troll hair spouting in unruly fashion from the Norwegian rooftops was in fact … grass. Grass? Why I asked myself, are Norwegian’s planting lawns on their rooftops? And if someone or a whole bunch of someones are going to plant lawns on their roofs shouldn’t they at least have the courtesy to mow them? Apparently not. You can well understand my mystification, my, outrage even. Being born and raised in the achingly bland suburban environment of Mississauga, Ontario, a sight like this one left my brain practically hemorrhaging. So, what the heck is going on here? My arid sensibilities cried. Gadzooks! Had some strange grass plague afflicted their homes? Certainly, no one would do this on purpose. Norwegians are famously bashful folk, especially to strangers. But after some digging, I managed to get the truth.
Okay, here’s the skinny. Yes, they do it on purpose. Norwegians intentionally plant lawns on their rooftops, lawns which they never mow, never fertilize and never water. (Though, to be fair, it rains quite a bit in Norway.) These lawns are left to grow as wild and unruly as they please, giving them a distinct Troll hair look. But why? Later, I would find out that this strange phenomenon had spread to other places in Europe, and to the world. Was there something to these weird looking bushy grassy rooftops after all?
Being in the building industry for many years, I had heard whisperings of the so-called green roof, but I had never actually seen one. Beauty is certainly in the eye of the beholder. And I have to admit, to my eye, which has been conditioned to accept the North American standard of dark asphalt as the epitome of beauty, it looked pretty damn, well, awful. But what is beauty, but a preconceived notion? And then I found myself asking: What lies beneath the surface of the grass roof? Why not install regular old shingles like normal everyday North American people?
To find out, let’s compare the common asphalt shingle found on top of most houses in North America to the grassy rooftop of Norway:
The Asphalt Roof:
- Asphalt shingles are made of asphalt, fibreglass, and often contain formaldehyde and other chemicals
- Each time a standard shingle roof is added to the landscape a portion of the natural environment is lost forever
- Does not retain water and therefore contributes to flash flooding, water runoff and other storm water related issues
- Standard black shingles amplify heat during peak summer months
- Solar reflecting shingles may mitigate some heat from the sun but not nearly as effectively as a living roof
- Provides no insulating value whatsoever in peak winter months
- Must be replaced every 15-20 years
- Old roofing materials can be recycled into other asphalt products such as roads but are often sent to a landfill
The Grass Roof:
- Grass rooftops are made of … grass!
- Recovers green space
- Reduces negative impacts of urban development
- Improves Storm Water Management
- Can be significantly less expensive to install than a traditional storm water management system
- Improves water quality
- Conserves energy
- Mitigates urban heat islands
- Increases longevity of roofing membranes
- Reduces noise and air pollution
- Sequesters carbon
- Increases biodiversity by providing wildlife habitat
- Provides space for urban agriculture
- Can provide aesthetically pleasing and healthy environments to work and live
- Improves return on investment over traditional roofing
- Is 100% renewable
Hmm. Could the Norwegians be on to something? Everything in my monochromatic soul wants to shout no, but I am forced to admit that maybe, just maybe they are.