Material property benefits
PVC-U is sometimes erroneously perceived to be 'unsustainable' because it is not organic like timber. But being organic is only one element of sustainability, and a less critical one in the exterior building products market, which by definition needs products to be highly durable, low maintenance and thermally efficient. PVC-U is an inherently insulating material, whereas timber is porous and aluminium is a conductor (prone to thermal bridging issues, a major cause of condensation) On a like-for like basis PVC-U is the most thermally efficient material. PVC-U is also fully recyclable and can be recycled up to ten times with no material degradation. This gives a piece of PVC-U a minimum life of 350 years (source: BRE) Timber is not recyclable and is most commonly disposed of by burning, which can be carcinogenic. Clearly PVC-U is a sustainable material, and offers better value for money than timber or aluminium to boot.