During the ice ages, why were hunter-gather societies in much of europe unlikely to use large wood timbers for their dwellings?

Hunter gatherers were not likely to use large wood timbers for their dwellings simply because large trees would not grow in this environment during the Ice Ages. Trees can survive in temperatures as low as 6 degrees Celsius and so would not flourish during the ices ages. Grasslands would more likely flourish (in summer months) in this type of environmental conditions.