NetworkHR Health & Environment Green Roofs

NetworkHR Health & Environment Green Roofs

Sewing the seeds of savings

In July of this year, I took a short break from the grindstone that is Network HR, and headed home to Sheffield in the north of England. Whilst there, I took a trip over the Pennines the small mountain range that runs down the spine of England to Manchester. One of Manchesters biggest attractions is the newly erected Wheel of Manchester. From the highest point of the wheel, it is possible to look across the whole city, and out into the lush English countryside. As I drank in the fabulous view, I noticed how dull and grey the rooftops of the whole city were compared to the countryside beyond. It also made me think that perhaps many of the shops, office blocks and apartment complexes were missing an opportunity to save money and save energy.

As you may have noticed from previous issues of Network HR, we are keen to explore ideas that will (i) help your organisation conserve both energy and money, and (ii) provide a healthy and environmentally friendly workplace for your staff. For example, in our last issue we looked at the environmental precedents set by many of the newest buildings erected here in China, including many of those built for the Olympics in Beijing. Therefore, as I looked across at Manchesters rather dull cityscape, my mind began to drift towards an idea that would not only save money and energy, but would also brighten up the city and many workplaces green roofs.

Ok, so first things first. What exactly is a green roof? The term is widely used, but not always accurately so. For example, roofs with solar-panels or sky-lights are sometimes labelled ‘green roofs.

However, this is quite a liberal use of the term. I want to be more focused with our definition: ‘a green roof is the top of a building covered with vegetation to help conserve energy. In winter, the greenery helps to insulate against sleet, snow and sub-zero temperatures. And, in summer, it helps absorb the heat from the beating sun.

Exactly how does this work? To explain the theory behind green roofs, I want to make a slightly unusual comparison. I want to compare your building be it a factory or an office block to my head. Strange, I know, but stick with me. I am sure you have noticed from my picture that I have no hair. This may save me money on shampoo and styling products, but it also means that I need to pay extra attention to extreme weather conditions. I can imagine that, at this point, there are a few quizzical looks amongst NHR readers about my comparison. So, let me explain in more detail.

The head plays a major role in controlling human body temperature, the same way that the roof plays a major role in controlling the temperature of your building. In cold conditions, 40% of our body heat is lost through the head. This explains why, when the biting winter winds come whipping across the Bohai and into Tianjin, I need to pull my hat down over my ears and find myself a hot drink. It also explains why, when the mercury begins to dip, you need to turn up the heat in your office. It is not just in cold conditions though, that the head controls body temperature. When summer comes along and temperatures begin to rise, the head also absorbs heat. This is why, to keep cool, I tend to douse my head in sunscreen, drink lots of cold beverages and even enjoy the occasional ice-cream. It is also why you might decide to turn up your air-conditioner so that it is blasting ice-cold air across your office.

Naturally, to perform at your best, you want to keep warm in winter and cool in summer. However, doing so can often use vast amounts of energy. Obviously, this is bad for the environment. To generate the electricity needed, we must burn an increased amount of fossil fuels, which means greater CO2 emissions and a heightened risk of climate change. Also, on a level that directly impacts upon your organisation, this means higher utility bills. Unfortunately, though, on such a large scale, conserving energy is not as simple as putting on a woolly hat to prevent heat loss. However, green roofs are a relatively straightforward solution that can produce long-term energy savings. In fact, a 2006 study by the Canadian Environment Energy estimated that they can save up to 26% on energy bills.

Ok, so lets get a little more detailed and discuss green roofs in greater depth. Whilst the type of roof may vary, we can essentially divide them into two major categories extensive and intensive. Extensive: The extensive green roof is the most basic approach, but also the most cost and time effective. The objective is solely to save resources, both in terms of energy and also in terms of upkeep and maintenance. This means that they are simple. After they are installed they can be left alone they do not need anyone to water or tend the plants. This means they are usually made-up of hardy plants that do not need to be regularly cut or watered.

Intensive: An intensive roof is a slightly different scenario. Instead of focusing just on saving resources, they look to do a little more. They save energy, but also incorporate an aesthetic element. For example they can be used as decoration to brighten a dull looking skyline, such as Manchesters. Or, they can be created to give employees an area in which to relax and to get away from the stress and strain of their daily work. Many organisations in Germany, Austria and Switzerland use intensive green roofs to create roof tops gardens in which their employees can relax. Because of this they are often more expensive to install and, once in use, require greater maintenance.

Green Roof Examples

So, if you are interested in green roofs, where can you find some great examples? Unfortunately, in China right now, this is not too easy. Even though there are plenty of examples of roofs that have strong environmental elements the roof of the Water Cube in Beijing saves rain water and absorbs heat for example- there are no large scale examples of the green roofs we are discussing. Therefore, to see green roofs in action, we need to look further afield. The best country in which to see some great examples would be Germany. Since the 1960s, German planning laws have included specific provisions for green roofs. This means up to 10% of newly erected buildings have them. For some slightly more specific and well known examples, we can also look to the USA. Green roofs may have a far shorter history in America than in Germany, but they are growing fast. A fantastic example of a major multinational organisation looking to save energy and money is automotive giant Ford. In 2003, it installed an extensive green roof at its plant in Dearborne, Michigan that spanned a staggering 450,000 square feet (approximately 135,000 square meters).

This was an ambitious and expensive undertaking, as explained by Donald Russell of Fords Environmental Quality Unit It costs twice as much as traditional roofing, but there are paybacks. Russell went onto explain that in winter, the temperature of the building was three degrees higher than before, thus saving huge amounts of money in heating costs. Russell also expects the green roof to last longer than its traditional predecessor, All indicators are that it will last longer, because there is no UV degradation from the heat. A final benefit the roof provides is psychological. Russell believes that installing the roof gave Fords employees a major emotional boost, The workers are kind of proud to work in a place like that. The workers at Ford are rightly proud of their workplace and their employers great example. However they are used whether just for energy saving or also for decoration green roofs are an innovation we hope to see more of in China.


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