Q.Can you possibly tell me which type of green house is most eco friendly in terms of its construction and materials. Cedar or aluminium?
This is for a school eco garden where we want to make the right choices to help the children learn about how their choices affect the environment.
(Mrs Helen Toft, 10 October 2008)
A.It’s a very interesting question – and one that isn’t quite as straightforward to answer as you might think. Although the endless sound-bite pronouncements by politicians and celebrities have rather encouraged us to see everything as either “good” or “bad” in environmental terms, the real world is, of course, considerably less simplistic!
The Benefits of Wood
In general terms, wooden greenhouses score very highly. Wood is a renewable and sustainable material, with lower embedded energy costs than aluminium and wooden frames lose considerably less heat, making them more energy efficient especially if you’re planning to heat the greenhouse in the winter.
If you can find a manufacturer that uses wood from sustainably managed forests – and ideally within your own local area – then you are probably making the best choice you can, but this may be a tall order, I’m afraid. Unfortunately, I don’t think the Forest Stewardship Council have accredited any cedar greenhouses yet – as they have some designs of conservatories and sun-rooms – but it might be worth checking with them before you finally make a purchase.
Perhaps the best thing to do is ask the manufacturers and suppliers of any of the greenhouses that you’re considering a few straight questions about their policy and general stance on the environment. In today’s world, no company worth its salt should be caught without answers.
Your question was specifically about the construction and materials – but it’s worth pointing out in the context of teaching youngsters about how their choices impact the environment that other factors obviously play their part too.
If, for example, you were to have a wooden greenhouse delivered from the other end of the country, the added carbon cost of all that fossil fuel might end up making an aluminium one (which is lighter and so less energy demanding to transport) delivered from your local DIY store seem less of an eco villain!
The environmental performance of the company supplying or manufacturing the greenhouse will also have an effect on the eco-friendliness of the final product, but like the rest of these sorts of ancillary factors it is very difficult to quantify.
A Greenhouse From Plastic Bottles?
One idea that a number of schools have tried and found to be rather fun is making a greenhouse out of recycled clear plastic bottles. I think there are some purpose-designed frame kits around, but you might be just as well off getting a local joiner or handyman to build a frame for you – out of wood, of course!
It’s a great way to encourage the children (if they need it, which I doubt) to do their bit – and it can involve anyone and everyone in the community, since I think you need upwards of 2,000 bottles or so. If you can find a source of reclaimed timber for the frame, the whole greenhouse would be about as eco-friendly as you’re ever likely to get.
I do hope that’s given a few useful thoughts; best of luck with the project – it sounds like a great way to teach children about the environment.