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There is a push happening in the US as high as President Obama to paint all roofs across the country white. The benefits of white roofs are frankly astounding & it won’t take long before the white roof movement hits Australia in a big way.

Buckley Street Marrickville is an easy example of a landscape that will produce its own Heat Island Effect

I suspect there will be resistance to change due to familiarity of red roofs.  Also, some people will be concerned about the Feng Shui of white roofs as they represent death or mourning.  Red roofs, the colour of most of Australian tiles, means money coming in.  Black or dark grey tiles are seen as a cloud of depression & doom hanging over your home & to be avoided. Blue roofs are the worst as they represent water overhead causing the residents to always be drowning in problems.

According to the US Department of Energy white roofs keep buildings cooler in summer & slightly warmer in winter & can save 10-15% of energy used for air conditioning.

White roofs & light coloured pavements change the solar reflectance (albedo) because the sunlight comes down & is reflected back into space, thereby not adding to the greenhouse gases.

White roofs do not add to the Heat Island Effect, something that is going to become a real issue in the years ahead if not enough is done to reduce it. We will all be boiled alive whilst going about our business, literally.  Death due to heat will become more commonplace. Manhattan has been found to be 5 degrees (22 F) hotter than surrounding suburbs simply due to the Heat Island Effect.

To combat the Heat Island Effect there needs to be a combined approach of planting more shade-producing broad-leaf street trees & more ground vegetation.  Asphalt should be removed where possible, especially great expanses like car parks.  Of equal importance is installing green roofs & walls or using solar reflective white coatings on both walls & roofs.

Research by the US Department of Energy found if all the roofs on Earth were replaced with white roofs & light-coloured cement pavements were used in all cases, the sunlight reflected back into space would be the equivalent of removing all vehicles off the roads worldwide for 11 years.  This is significant, hence the push in the US to make all roofs white. If all the walls were white or light coloured, the positive impact would be even greater. If all cars were light-coloured, the car would need less air conditioning to keep it cool. Soon you won’t be able to by a dark-coloured car.

Bourke Street Surry Hills will be a better street than many to live in despite the high traffic because of the presence of many large broad-leaf street trees

The monetary cost of white roofs & light-coloured pavements is equivalent to the cost of materials we use now. White roofs can be used in combination with solar panels.

Already available on the market are nanotechnology heat reflective paints that can be painted over roof tiles or sheeting. These reflect between 90-95% of UV, infrared & visual light & prevent heat transfer into the roof space.  Tests have shown that roof space under a dark roof can be up to 50 degrees higher than outside air temperature.

There has been some resistance to white roofs for fear they will get dirty & look bad within a couple of years. They will, though some products have Titanium Dioxide in them that is said to make the roof self-cleaning.  How fast the roof becomes dirty & loses its reflective ability depends on the location of the building & the slope of the roof.  The dirt that dulls the white roof is airborne dust & particulate matter from traffic pollution. It’s the stuff we breathe in daily & what street trees help prevent coming into our homes.  The roof can be power cleaned once or twice a year to return the colour back to sparkling white.

I suspect the need to wash one’s roof regularly will be another source of resistance to white roofs.  My bet is that eventually governments will offer significant tax rebates for those who have white roofs.  Plus power costs will be at nightmare levels so people will be forced to do whatever is available to help keep costs down.  I’ve just heard on ABC News tonight a warning that electricity costs will be 100% higher by 2015 & 500% higher by 2020.  We will be forced to change & accept sustainable & green cooling & heating methods.

Car parks like this one in Marrickville could easily be changed to not only make it look visually more attractive, but also to lessen its heat producing effect

That’s when trees are going to undergo a revolution in image & people will return to being tolerant about fallen leaves, wildlife & fixable cracks to paths & fences.  People are going to want tall shade-producing trees near their home & on the street because of the tree’s ability to lower power bills by cooling the air. As the Heat Island Effect increases, so does air pollution, especially pollution near the ground & the trees’ natural ability to clean the air will be recognized as a significant benefit.

New York City found that the ability to cool an area cheaply & effectively was by planting street trees so they started the 1 Million Trees program. The next best for cooling an area is by creating green roofs, using light covered roof & wall surfaces & planting in open spaces.

The Manhattan Young Democrats have set up the White Roof Project to curb the effects of climate change, to make the city cooler & to lower New York City’s energy use & their program is very successful.  Volunteers paint city roofs with reflective white paint purchased from donations. You can even have a white roof named in your honour for the paltry sum of US$1,000. I applaud them for their idea, their commitment & their hard work.  For a great visual explanation of the Heat Island Effect & how painting roofs white can curb climate change see –  http://www.whiteroofproject.com/how-we-can-curb-climate-change/

Australia should be seriously looking at white roofs & white walls. The only exception should be a green roof or green walls with living plants.

 

 

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