Located in the heart of the historic city of Viseu, the Church of Mercy has a value of exceptional quality in terms of architecture, history and technic, positioning itself as one of the buildings that define the quadrilateral of the churchyard of the Cathedral. Due to the positioning on the hill in which it stands, together with the Cathedral, is assumed as a visual reference, particularly in the north of the city. It establishes a special relationship between the uptown and the hillside, assuming an especial role in the various houses that develop till the bottom, shopping and services area par excellence. It is a building that has been altered over time in which is highlighted the construction of the main elevation, as we know it, in 1775 and the main body of the Church in 1846.The intervention will aim at the recovery and rehabilitation of all the exceptional elements and reformulation, in some cases demolition, of poor additions that will prove not have significant value. Historical information collected allows dating different periods of construction in the building to substantiate the architectural choice.