What are Green Roof Systems?

Green Roofing System in a Rural Setting

Green Roofing Systems are More Than Just Pleasant to Look at! They Can Save You Money Too.

Businesses carefully choose commercial surveillance equipment. They painstakingly plan on interior design and HVAC system installation. But do they always choose the best roofing systems? Not so much. When it comes to selecting an environmentally-friendly, energy-saving roofing system, few solutions can beat the effectiveness of a green roofing systems.

Today, we’ll briefly discuss the design behind green roofs, their cost-savings benefits, and why your business should at least consider one of these living roof systems. Afterwards, you should be able to see why so many businesses choose them and why local governments like to offer tax incentives for them.

How do Green Roofs Work?

Beneath every beautiful green roof is an intricate, multi-layered system that is designed to be self-sustaining.

At the very bottom is a waterproofing layer (or membrane) that prevents moisture from slipping into the subroof. Water instead runs into pre-cut drains. Above that layer lies a durable root barrier that (you guessed it) bars roots from delving too deep. Halfway to the top lies the drainage layer, which permits moisture an avenue of escape. This prevents over-saturation in the growing medium which we’ll discuss in a moment.

Second to last, comes the filter cloth which allows the release of extra moisture into the drainage layer but prevents the growing medium from escaping. Finally, the growing medium sits on top. It houses all the top plants and provides their nutrients. It actually contains very little dirt. It’s specially engineered to prevent pests and maximize plant livelihood. To summarize the overall structure:

  • Bottom: Waterproofing
  • 2nd Layer: Root Barrier
  • Middle Layer: Drainage
  • 4th Layer: Filter Cloth
  • Top: Growth Medium and Plants

Exact construction may very lightly between companies, but that is the typical design.


How Long Do Green Roofs Last?

While green roofs are relatively new to the US, they’ve been increasingly popular in Europe over the last few decades. Their lifespan generally spans between 30 and 50 years. That’s about the length that some premium roofing materials provide, though green roofing installations offer some additional perks (which we’ll discuss later).


How Expensive is a Green Roof?

Base level costs vary based on which professionals you talk with, but you can expect green roofs to run from $10 to $20 for each square foot of roofing. That range factors in installation and prep costs, as well as materials. When you choose a roofing company to install your green system, make sure to ask what their costing includes.

Installation and annual maintenance costs will also depend on what manner of green roof you decide on. There are three categories:

  • Extensive: shallowest
  • Semi-Intensive: middle depth
  • Intensive: deepest

Extensive systems have a smaller layer of growth medium. As a result, they support fewer species of plants. On the other hand, they also require less roofing support and reduced maintenance.

Semi-intensive systems provide a larger pool of plant options for your roof. They do not sustain the largest plant varieties, however.

Intensive systems come with the steepest load requirements, but they also support a massive variety of plant life. The largest designs, in luxury homes or atop corporate offices even feature trees and large shrubs. Intensive systems need significantly more care, and they cost the most by far.

Depending on your local ordinances, your project may qualify for government cost-sharing or tax incentives. You should do a little research beforehand, especially if you are planning for a business.

Energy Savings

Do Green Roofs Reduce Energy?

Green roof systems absorb heat from the surrounding air. They also reduce the overall surface temperature of the roof, which cuts down on interior energy waste. How? With less heat penetrating the roof, your HVAC system won’t have to work as hard conditioning the air. The subsequently shorter run times means slowed part degradation and less energy consumption.

Why Have a Green Roof?

Green Roof on Top of a Rural Home

Green Roofing is Often Incentivized By Local Government Tax Programs. See What Your Area Has to Offer.

It’s a reasonable question. What are the benefits of a green roof? First, there’s the considerable energy benefits you’ll enjoy. Reduced operating time for your HVAC system means lower electricity costs and reduced stress on your air conditioning parts.

There’s also the environmental effects. Plants naturally absorb ambient heat and air pollutants to refresh the surrounding area. Because your plants and the underlying growth medium absorb water, a green roof also reduces the amount of rain water spilling around your house (or office building).  The long lifespan of theses systems is also very appealing.

Beyond all these easily recited benefits is the gorgeous, wholesome beauty of natural plant life. The psychological boon that this provides to homeowners is unquantifiable, but real. You only have to talk to other homeowners with green roofs to see it.

Green Roof Benefits

  • Energy Savings
  • Environmental Benefits (Air & Heat)
  • Reduced Rainwater Runoff
  • Longevity
  • Natural Beauty
  • Exterior Sound Dampening

Do Green Roofs Provide Insulation?

Yes, and this grows more noticeable the thicker the growth medium layer is. Both interior heat and cool is preserved as a result. However, there’s a second insulating effect that many homeowners don’t consider: noise reduction. A thick layer of soil absorbs sound from the surrounding area so that less is transmitted into the home.

Green Roof vs Traditional Roof

A Modular Version of a Green Roof

Some Green Roofs Come in Modular Form. This Makes it Easier to Customize Roof Access.

Green roofs provide several environmental and energy savings benefits, you’ll notice that the investment costs are significantly higher than other commercial or residential options. The average cost per square foot of a green roof ($15) is almost double the average of PVC or TPO roofing.

That being said, green roofs also have a much longer lifetime when well maintained. Reflective roofing can match or better the cool-roofing effects of living roofs, but they can’t imitate the air cleansing benefits. Normal flat roofs also don’t have the same waterproofing abilities and impact resistance. In summary:

  • Green roofs cost twice as much but can last twice as long.
  • They have better environmental benefits.
  • They provide better waterproofing and storm protection.

Ask About a Quote for Your Office Building!

Want to learn more about installing a green roof in New Orleans, LA or a nearby city? Our team at ECO Commercial Roofing would love to talk with you about it! Give us a call today at 877-406-7663!

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