Arches are a common feature in houses today. It is a technology which has been in use for hundreds of years and has withstood the test of time as evidenced by the numerous arches seen in ancient buildings and old houses in Sri Lanka. Masons have been trained by Practical Action on the technology and the practical use of several types of arches, some of which were constructed at Practical Action pilot project sites. This technical brief discusses about those arches technologies.