How long your aluminium windows will last depends on their quality. They should last 20 -30 years at least, but have been known to stay in good condition for up to 45 years. This is considerably longer than uPVC and wooden double glazing.
Llanfechain
Llanfechain is a little town and also neighborhood in Powys, Wales, in between Llanfyllin as well as Llansantffraid-ym-Mechain on the B4393 road. Historically it belonged to Montgomeryshire. Afon Cain goes through the town. It has a population of less than 500. Llanfechain might imply "parish or church (llan) of the Cain valley" (from Llan ym Mach Cain meaning "church in the field or plain of the Cain" to Llan ym Mechain and afterwards Llan-mechain, which becomes Llanfechain as a result of the usual anomaly of'm' to 'f' in Welsh). However, it might likewise imply "tiny (fechan) church or church (llan)". Punctuations of placenames vary substantially with time, so tiny variations such as chain/cain as well as fechain/fechan are plausible. The name in the form Llanveccheyn is first encountered in 1254. It has also been referred to as Llanarmon-ym-Mechain, ym-Mechain refers to its location in the medieval cantref of Mechain, hence 'Church of St Garmon in Mechain'.