Let's Take a Look at Eco Roofs for Homes

Mowing an Eco Roof

Eco roofs, or turf or green roofs as they're sometimes called, are ones which have plants growing on them - usually grasses and/or flowers for residential roofs but they can extend to having shrubs and trees on large commercial buildings.

There are many benefits to having a living roof, they're largely self-maintaining and can last twice as long as regular roofs as well as providing a great deal of heat and sound insulation, as well as other environmental benefits which I'll go into more detail below.

The idea of living roofs isn't new, the history of sod roofs dates back to the middle ages particularly in Scandinavia where traditional Viking houses used them.

Here's an example of an old Norwegian house courtesy of Paweesit:
old Norwegian house with green roof

Modern use of green roofs started in Germany in the 1940s and that country remains a leader in their use today, however over the last couple of decades they have become increasingly popular throughout continental Europe, in the UK, and in the United States as well. This video from Grand Designs shows the basic process of installing one on a new build:

Environmental Benefits of Eco Roofs

There are a range of environmental dividends provided by this kind roofing and different advantages are accentuated depending on your local climate, so I'll outline the main ones which have been demonstrated by research.

  • The insulating effect of the additional mass will reduce your energy consumption for heating and cooling.
  • Additional benefit is accrued in the warmer months due to evaporative cooling.
  • Stormwater runoff is often significantly reduced, and the water is filtered and cleaned by the roof.
  • Air quality is also improved by removing pollutants such as sulfur dioxide and nitrous acid from the air. There is also a carbon sink effect removing CO2 from the air.
  • In metropolitan areas they can also contribute to reducing the urban heat island effect.

If you'd like more information there is a useful list of references, reports, and articles on the environmental aspects of eco roofs at Wikipedia.

When To Go Green With Your Roof

The best time to install an eco roof is on a new build, but they can be retrofitted to most existing houses.

While you can do this at any time, a good time to seriously think about it is after storm damage to your roof. Although it would usually be cheaper to go with a licensed traditional roof repairing contractor, because you're already facing expensive repairs then going the extra step to a full roof replacement might be more economically feasible for you at this time than at any other time - particularly if you're expecting an insurance payout.

If however your financial circumstances mean that your can't justify the additional expense of replacing your damaged roof with an eco one, then you can still take the environmental impact of traditional roofing materials into consideration. Major roofing supplies manufacturers like Braas Monier are now taking into account issues such as production, materials, and logistics when considering their ecological impact. Just do a little research about the materials to be used on your roof replacement and you'll be ale to make a difference.

Important Considerations

Whether you're considering doing this as a DIY project or by using professional green roof contractors, there are some important things to consider before you proceed.

You need to get a licensed structural engineer or architect to inspect your house before you do anything else. Some houses won't be able to support the additional loads of a green roof during rain or snow, or support modifications may be required before work can proceed. Failure to do this might not only result in structural failure, but could also put you in breach of building regulations and invalidate your insurance.

Some states and municipalities offer rebates or subsidies for green roof installation so you'll want to do some research on this before you begin to ensure the work meets the requirements - contact your local or state government to find out what's on offer. Here's a guide to incentives from the EPA - it's from 2010 but it's still a good starting point.

Roofs sloped at over 30° are usually unsuitable - if your roof is close to this angle, or if you're in any doubt, seek professional advice.

Where possible try to source your materials locally as shorter transportation distances will reduce the carbon footprint. Also avoid using fertilizers as these will be washed off the roof and become pollutants.

One tip I strongly recommend, if you're going to do this DIY then consider trying it on a small scale by greening a shed or garage roof before going all the way and installing one on your house - the experience you'll gain will be invaluable and will very likely save you time and money when it comes to the major project. I also suggest you read the EPA's Design Guidelines for Green Roofs.

I hope this has piqued your interest in eco roofs, so if you have any questions or comments please message me or join the discussion on Twitter or Facebook.

You might also like to read:
Should You Repair Your Roof Before You Sell?
6 Reasons Your Roof May Be Leaking (And What To Do About It)