It depends on the size and type of extension. Small porches or flat roof extensions are very reasonably priced. More substantial two storey extensions can be expensive. In general, the price is roughly proportional to the amount of space you add to your home.
Llanarth
Llanarth (population 1,616) is a small village as well as community in Ceredigion, Wales, situated on the A487 in between Aberystwyth and Cardigan within 3 miles of both Aberaeron and also New Quay. Llanarth has a petrol station, post office, a primary school, a hostelry, a butcher, a Spar convenience store and also a garden centre. The parish church of St David's, as soon as committed to St Fylltyg, is a Grade II listed building. It was renovated in 1872. A stone in the churchyard is in some cases mentioned as bearing the Devil's impact. According to tale, he was attempting to swipe among the church's bells one evening, but woke the vicar, that drove him off. He left the footprint as he ran away.