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.
Llanfyrnach
Llanfyrnach is a village, area and parish in Pembrokeshire, Wales. The village remains in the electoral ward of Crymych. The village of Crymych and the communities of Hermon, Glandwr and the eastern part of Pentre Galar remain in Llanfyrnach church. Llanfyrnach indicates the church of St Brynach. Llanfyrnach village remains in a remote upland area on the headwaters of the River Tâf, about 11 miles (18 kilometres) from Cardigan. The village stays little, with much of the labor force employed in transport. The population of the parish was 542 (1801 ), 933 (1851 ), 954 (1901 ), 844 (1951) and 837 (1981 ). [2] The location stays mostly Welsh-speaking; the proportion of Welsh audio speakers was 100% in 1891, 97% in 1931 and 82% in 1971.