It is hard to say categorically whether uPVC or vinyl windows are environmentally friendly. The way to look at the problem is to consider the metrics of green interior design as laid out in LEED (Leadership in Energy and Environmental Design).
Although it is hard to find the perfect green product it is often a matter of weighing up the pros and cons of a particular material, practice or service and coming down on one side or another. Thus, although some green interior designers complain about the weak environmental standards of farming in China and the sometimes high levels of VOCs found in bamboo flooring and other products, it is hard to not classify bamboo as ‘green’. It is a renewable resource, it produces more oxygen than trees, it holds the soil together, it is antimicrobial etc. All these plus points clearly outweigh the negatives.
In the case of the uPVC windows they qualify as environmentally friendly as they greatly improves insulation in a home. This impacts the energy saving metric and the CO2 metric. As uPVC windows reduce heating and cooling costs they thus make a home more energy efficient and lessen the need for electricity made from power plants that burn fossil fuels and increase atmospheric CO2 levels.
Another positive for uPVC is that it replaces timber frame windows. This helps to conserve the valuable resource of hardwood, and thus has relevance to the LEED metric about resource management.
On the other hand, the production of uPVC, vinyl and PVC produces dioxins that are known to be carcinogenic. The incineration of uPVC also releases dangerous dioxins. In certain areas of Germany uPVC has been prohibited for use by public buildings. This is clearly not in line with the LEED metric that a home product should not negatively impact air quality and human health.
Although scientific progress has been made with the safe disposal of uPVC through closed systems such as the Texiloop system in Europe and the Vinyloop system in Japan the resources and money needed to make such systems make them unlikely to become universal. Moreover, building such systems require a massive carbon input not to mention minerals and other precious natural resources.
This brings up the final negative point of uPVC windows. That is resources. To make vinyl chloride and uPVC it is necessary to use oil. Not only is oil not a renewable resource, it is the one resource that is probably most responsible for environmental catastrophe. Consider the Deepwater Horizon Oil Spill and the recent spill off the coast of New Zealand. These are just two instances in a long and sad history of how man’s dependence on oil has had a devastating effect on the environment.
The debate continues. Many energy specialists firmly place uPVC in the green camp. Many German municipalities clearly do not agree. From looking at the pros and cons of uPVC windows from the point of view of the guiding principles of green interior design it is the belief of the author that uPVC is not environmentally friendly, and so it is apparent that a green alternative to timber, aluminum and uPVC windows is urgently required.