Important price fluctuations can be observed on the market. The average price of a window is 420 (net of tax). However, as soon as the cost of installation is added, the price can rise by at least 80%, to 760. Since 2004, the average price of a window has increased by 38%. Several factors explain this, including the quality and type of material used: the market has shift towards aluminium on one hand, and towards more efficient products on the other hand. However, in terms of the volume of products sold, PVC largely dominates the market, with 62% of market share, followed by aluminium (22%) and wood (13%). However, looking at value estimates, aluminium accounts for 33% of market value and PVC for 49%

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