On sunny days, the temperature of a conventional asphalt roof can climb to high as 65°C (150°F); one of the reasons why city areas tend to present with a higher mean temperature than less built up areas during warm spells. This adds to the degree that office air conditioning needs to work to lower temperatures indoors to an HSE accepted level and asphalt roofs also do nothing to alleviate the strain put on our sewerage systems as untreated and undeterred overflow runs off during rainy periods, often leading to flooding in our city streets.
Rain water harvesting goes a long way to minimising the impact of this last occurrence but there is a better solution that pretty much ticks all the boxes as far as environmental benefit as well as delivering long term cost reduction outcomes to businesses (and, for that matter, residential occupiers).
Living roofs go back a long way; they were common among the sod houses on the American prairie and can still be found on log houses and sheds throughout northern Europe. What makes the concept a commercially and environmentally viable one today is the advance of technology; water-proof membranes now make it easier to implement green-roof systems that capture water for irrigation and allow drainage (of filtered water – much better for the drains). The benefits in terms of providing environments for displaced flora and fauna to re-inhabit established growth areas as well as the cost benefits (more of this later) mean that many public and private organisations are looking at green-roofing as a matter of course – in Germany, Switzerland and Austria living roofs are required by law on roofs of a suitable pitch.
If you want to read more on the subject, the UK guru on the subject is Dusty Gedge, a wildlife consultant (http://www.dustygedge.com/greenroofs.html
). For now, consider these 3 headline benefits for your company’s wallet and morale:
1. When rain falls on a conventional roof, every drop plummets down into the sewerage system pushing the storm drains to breaking point. London, for example, is already building living roofs into its future plans in an attempt to moderate the constant threat of street flooding (London Biodiversity Partnership -
2. The soil mixture and vegetation on a green roof act as insulation and can reduce your cooling costs (in the summer) and heating costs (in the winter) by as much as 20%, saving you not only money in utility bills (and off-setting the higher cost of implementing a green roof system in the first place) but also potentially bringing your utility bills below the CRC threshold which, when it comes into force in April 2010, will add another cap and trade burden on already heavily taxed businesses.
3. Finally, if you installed (grew?) a living roof on your office building your employees might not visit very often (though it has to be a nicer place to eat your lunch than at smoggy street level) but they’ll all know its there, adding habitat to the town or city, filtering the rain and moderating temperatures. In an age where generation Y is more and more concerned with the ethical credentials of its prospective employer, would you not want to attract the best through creating some green space where before there was only asphalt and gravel?
Find some green space in your current environment and think about it; if you can’t find any, think about it a whole lot more!
Peter Wognum is CEO of Biz4Green Limited, a single-source supplier of technology supported solutions that drive new (better) behaviours to reduce business operating costs whilst being more climate-friendly. Biz4Green was launched as a vehicle to encourage and assist businesses of all sizes take pragmatic and, in most cases, no- or low cost, actions to significantly lower their carbon footprint whilst measurably reducing their operating costs.
During his career Peter has held a number of positions as operations director and global development director in the automotive, healthcare, education, finance and retail fashion sectors. Since escalating a personal passion into a corporate activity by creating Biz4Green, he has worked with companies in areas as diverse as the financial, banking, construction, consulting, recruitment, aviation and training sectors.
In addition to his corporate and educational activities, he also writes a lively weekly column for Director of Finance Online (www.dofonline.co.uk/blogs/eco-finance), joining the dots between the practices of cost reduction and carbon reduction.