I use a 12 foot extender pole for most domestic jobs, I have an 18ft for the odd window I cant reach with it, over conservatories etc. On the van I have a 40ft and a 60ft carbon fibre poles. These are used only for commercial jobs. Four poles reach all I will ever need. But for day to day domestic use if you want to save pennies go for a 18ft extender, cheap, light, easily replaced. The only problem is in tight spaces between houses, close to a fence, wall etc, with a 2 section 18ft.