Although most of Machynlleth's buildings have come to be more polite than vernacular in character, the vernacular materials, particularly local stone and slate, long remained available.

Local timber was both used and re-used - timbers are sometimes seen pierced with mortices and borings irrelevant to current functioning - but its availability declined with time and it was supplanted by imported softwoods.

Slates were originally fixed by an oaken peg through the head of each, and later by nails, and lime mortar "torching" applied to their undersides helped them to adhere and stopped draughts and driven snow.