The amazing benefits of green and living roofs.

In part one of this series, we documented the amazing concept of growing grass, shrubs, trees, and even food on top of houses and buildings that can help clean up our environment and provide natural beauty. In this blog, we'll cover the benefits and drawbacks of green roofs, and a few resources if you wanted to learn more or consider a green roof for your home.

Benefits of green and living roofs:

Noise reduction:

Living roofs are extremely effective sound barriers, helping to drown out the noise of traffic or commerce in busy urban areas. The Chicago City Hall uses a living roof for this reason, and some homes under the flight path of San Francisco International airport have installed living roofs to help reduce the sound of the airplanes. Studies show that these living roofs can reduce noise levels by up to 50 decibels, and even a thin and basic grass roof will drop the outside noise by 5 decibels.

Water runoff control:

A living roof does a great job naturally regulating runoff from heavy rains and storms. Since vegetation and organic materials absorb rain, up to 42% of runoff, or about an inch of rainwater, is captured that would otherwise be wasted. That helps control flooding, overwhelming irrigation and sewer systems, and protects the natural balance of water.

Natural insulation:

Living roofs naturally cool down the outside air by acting as a heat barrier and also keep warm air inside the house in wintertime. Since heat rises, most of your energy loss is through the roof when you turn the heat on in the cold season. But living roofs can help keep you cool or warm, regulating the outside temperature by approximately 10 – 25 degrees Fahrenheit. The great thing is that the hotter the climate and outside temperature, the better an insulator a living roofs is, saving a lot of money on energy bills in warm climates.

Pollution control:

Trees, plants, and grasses help to alleviate the harmful effects of manmade pollution by converting carbon dioxide and other toxic gases into breathable oxygen. Installing livable roofs on big commercial buildings and office spaces in urban areas will not only slow the capture of gases, or greenhouse effect, and help filter airborne particles and pollutants that wash off into the soil. In fact, studies have shown that green roofs can trap up and filter out up to 95% of heavy metals that are caught in the water cycle.

Food production:

The renewed focus on producing organic, locally grown healthy food has vast potential when it comes to rooftops. Already, schools and many urban centers and office buildings are starting to grow fruits and vegetables on rooftops. Green roofs can also become hosts to edible growth and food production, especially on flat surfaces.

Fire resistance:

While it may seem like organic grasses and growth on rooftops may be more susceptible to fire, like we see with forest fires, in reality the soil and organic matter is actually fire resistant. Green roofs also hold a good deal of moisture that will thwart fires and burn slow, if at all. In fact, a “bare” roof of just shingles over wood is far more likely to a fire starting, especially over time as the surfaces are weathered and dry out.

Water filtration:

Green roofs on large surfaces can also act as natural water filtering mediums. In Australia, they are already using green roofs and walls as a natural filter to treat domestic grey water and wastewater, removing organic matter and pollutants.

A host to living things:

Green roofs serve as a natural micro ecosystem and that includes becoming home to a variety of birds, butterflies, and bees. Some people may not be comfortable at first with the idea of a lot of critters living on and in their roof, but as human beings overtake the landscape with pavement and pollution, the loss of native fauna is alarming. Already the huge extinction of bee populations is affecting our food systems and health. Green roofs can help reverse that trend, as we see with a large U.S. auto manufacturer who has built a giant bee farm on the roof of one of their factories.

Drawbacks and questions about green roofs:

Of course green roofs take some planning, work, and cost to install and maintain, but once you learn more, you’ll realize it’s well worth it.

Weight of the roof:

Green roofs are heavier than normal roofs, varying widely based on the depth of soil and the type of vegetation grown. Most green roofs weight only a little more than slate roofs, but weight can be a concern that should be carefully planned before any installation starts. It’s relatively simple to retrofit beams and columns of the existing roof to reinforce it for the weight.

Cutting and maintenance:

You probably only get near your roof when you clean out your gutters once or twice a year, but green roofs do take some maintenance. But don’t worry – when you’re mowing the lawn, simply take the weed whacker or hedge trimmers up onto your roof and cut everything back once or twice a year. Other than that, just check on the irrigation system and that’s all the maintenance you’ll need.

Watering and drainage:

In most climates, rainwater will be sufficient to keep your living roof green and thriving most of the year, but in the summer or arid climates homeowners can augment that with irrigation systems that are installed when it’s first built.

Likewise, green roofs have built in drainage systems similar to gutter and downspout systems on any roof.

Where can I get more information?

A green roof can help the environment, lower your energy costs, provide scenic beauty for your family, and also increase your home’s value. So where can you find out more about installing a living roof on top of your house?

Green roof facts. 

Is a Green roof right for you? 

Green roofs discussed by the U.S. Environmental ProtectionAgency (EPA).

Look up. The Green Roof Revolution is coming.

10 Ways "going green" around the house can also save you big money.

1. Install high efficiency light bulbs.
Did you know that the traditional light bulbs we still use waste up to 90% of their energy emitting heat? So replace your normal incandescent bulbs with high-efficiency Energy Star bulbs. They’ll lower your energy costs, last much longer, and are much friendlier on the environment.  Look for compact fluorescent light bulbs (CFLs), and light emitting diodes (LEDs), which you can buy at any Home Depot.  Those should save you a couple hundred dollars or more per year. And if every family in the U.S.A. replaced their bulbs, we’d reduce greenhouse gas emissions by one trillion pounds!

2. Program your thermostat.
A new “smart” thermostat, like an Energy Star, allows you to program specific temperatures for different times of the day.  Too often we set one temperature for night and one for day, or even worse, one set temperature, which is completely unnecessary. So you can lower the temperature at night (when you are under blankets) or during the day (when you are at work.)  The U.S. Department of Energy estimates you’ll save 5 to 15 percent per year by turning your thermostat back 10 to 15 degrees for eight hours a day.

It's recommended you keep the thermostat at 78 degrees or higher when cooling the house in the summer, and 68 degrees or cooler in the winter.

3. Stop pouring money down the drain!
Water is expensive these days, and the vast majority of indoor water usage comes from toilets flushing (30% of residential consumption) and showers. So install low-flow showerheads in your bathrooms - they only cost $20 or so and spray no more than 2.5 gallons per minute, saving you a couple hundred dollars per year. And install high-efficiency (low-flush) toilets, which can save a family of four a whopping $300 per year or more in water bills. If you don’t want to replace your new toilet, there’s a super simple (and free) way to turn it into a low-flushing model. Just fill up a few plastic water s with sand and place them in the tank!

4. Plug air leaks
Whenever you turn up your heat or AC, drafts can waste a lot of your money. Close doors, windows, and curtains appropriately to keep the heat or air in the rooms you need it most. Consider foam rollers or stick-on energy tape under doors or around window frames where the most air leaks in or out. In addition, caulking around exterior doors and windows and installing weather stripping in the chilly seasons can save you a bundle on energy costs!

5. Set up an outdoor compost bin.
Did you know that up to 50% of the trash in your home comes from food waste? All of that organic material goes in the trash and fills up landfills or is even dumped in the ocean! So instead of burdening our trash system with food scraps, set up a small compost station in your back yard. Over time, it will naturally break down organic material and create a safe, health fertilizer for your yard and plants. Studies show that separating food scraps from the trash also increases the amount of recyclable materials that are properly separated.

6. Optimize your water heater
If you don't have one installed already, put an insulated blanket around your hot water heater and also insulate the pipes around the water heater. Insulated blankets cost between $10 and $20, and you can get pipe insulation for less than $1 for six feet. Also consider turning the temperature on the water heater down to 120 degrees. Think about it – we turn the water on super hot and then use cold water to cool it down to the proper warm temperature – what a waste! Setting your water heater to a comfortable 120 degrees. It will save you up to $450 annually in energy bills…and use far less water!

7. Fans
In warm climates like the Central Valley of California, it takes far more energy (and money) to cool your house every year than it does to heat it. So during the scorching summer, instead of cranking up the air conditioning in the whole house, use fans. Ceiling fans are inexpensive to install and can cool down a room for cheap. Attic fans do a great job pushing hot air out of the attic, which accumulates because heat rises, attics have less ventilation, and roofing materials like tiles or shingles collect heat.

 On rooms that face the sun (on the south and west of the house) hang heavy solar-blocking curtains to keep the rooms cool, and consider energy efficient windows to protect against UV rays.

8. Native plants and shade trees.
Pull up your front lawn – which wastes an incredible amount of water for nothing more than an aesthetic. In fact, 30% of all water used in the U.S. goes to lawns and outdoor irrigation! By installing native species and draught-tolerant plants, you’ll have a much more attractive, natural, and garden-like front yard – and help the planet in a huge way. Shade trees plated on the south and west of your house can reduce AC bills by up to 15%, and many cities will come plant them for your for free.

9. Rainwater barrels and proper irrigation.
With California in the throes one of the worst draughts in U.S. history, every drop is precious – even rainwater. So why not put out a few barrels in your yard and next to your house, with gutters and downspout flowing into them. In a typical good night of rain, 300 gallons of water may be dumped on your roof alone, so capture this water and then use it for natural irrigation.

10. Go solar.
There is no doubt –the solar revolution is here, and in dry and hot climates like California, it’s nonsensical NOT to take advantage of the free and abundant sunshine. Thankfully, the cost to install solar panels on your roof or at your home has gone way down in the last several years, as technology and infrastructure has improved. Solar panels pay for themselves pretty quickly and grant homeowners huge tax rebates and incentives. If buying solar panels was too big of an investment, you can even lease them, which costs less than your energy bill every month!

For more information how solar works and availability in your area, click here.