maintenance matters Reduce Operating Costs And Increase Longevity Green roofs can save you time and money while increasing your building’s sustainability. By: Amber Poncé G Green roofs are a viable option for reduc-ing operating costs, especially when prop-erly planned and maintained. They do so by making the roof last longer and reducing the energy required to heat the building — and can even help in unexpected ways such as reduced hiring costs due to increased employee job satis-faction and retention. Green roof systems also reduce temper-ature control costs for a building. A study performed by the National Research Council of Canada compared the performance of a green roof to that of a traditional modified bitumen roof. The study revealed that the green roof reduced the energy demand for air condi-tioning by more than 75 percent in the summer months. Green roofs are more reflective than tra-ditional black roofs, meaning they absorb less light that would eventually become heat. In addition, plants release water into the surrounding air during photosynthesis, the process by which they convert light into energy. The moisture released creates a cooling effect, lowering the ambient temperature of the roof. This lowers the heat transfer from the roof to the floor below. It also reduces the temperature of the air taken in by rooftop heating, ventilation and air conditioning (HVAC) units, which reduces the amount of energy required to cool the air as it is run through the air con-ditioning process. Studies have shown that interaction with plants and the availability of natural views increases job satisfaction and reduces the number of sick days for employees. By creating an accessible patio with seat-ing adjacent to the green roof, employers By selecting a mixture of plants that bloom at different times of the year, you can minimize soil exposure and lessen the chance of weed encroachment. 38 CM/Cleaning & Maintenance Management ® • April 2010
CMM – Archives Apr 2010: 38
