The Church of Misericórdia of Viana do Castelo is located in the heart of the city, in Praça da República, just outside the historic city limits. The architectural complex that underwent intervention included the façade of the former hospital, the sacristy, the Chapel of Nossa Sr.ª do Bom Despacho, the cloisters, the bell tower, and the church itself — which consists of a single nave, a slightly protruding transept, and a rectangular main chapel of the same height and width, all volumetrically indistinct from the exterior.

Intervention goal

The project required a high level of multidisciplinary expertise, with particular focus on structural reinforcement of historic buildings, traditional civil construction, and conservation and restoration.

Steps and techniques used

The multidisciplinary intervention covered since structural reinforcement of masonry walls and wood structure from roof to traditional civil construction, conservation and restoration of tile panels, petreous elements, decorative painting on stucco, installation of anti-bird systems and technical installations of light and sound. All roofs were rehabilitated, replacing the entire ceramic coating and rehabilitating the structure in brown wood. The donkeys of the church cover were the object of structural reinforcement and improvement of supports in masonry, through metal binders.

After monitoring displacements in the dome of the main chapel and the triumphal arch using crack meters, the base of the dome was reinforced by installing an internal stainless-steel ring, anchored to the side walls through sleeved anchors. Prior to that, the masonry was consolidated by injecting lime-based grouts.

All exterior renderings were replaced, and new lime-based renders and silicate-based paint were applied. Interior plasters in the sacristy and chapel were also replaced. Conservation and restoration focused on the existing tile panels in the church, depicting the works of Misericórdia, as well as panels in the cloisters, sacristy, and chapel.

Decorative painting work focused mainly on the false vaulted ceiling covered in stucco, including ornaments and medallions representing the Santíssima Trindade, the Assunção de Nossa Senhora, and the Flight into Egypt. The work involved reconstruction of the base (lath and stucco), cleaning, pictorial reintegration, and consolidation. Larger gaps were only replastered and left without visual reintegration.

At the former hospital façade, stone conservation involved removing biological colonization, crusts and black films, treating joints, and consolidating areas with gaps or granular disintegration using ethyl silicate.

As a preventive measure, two anti-bird systems were installed: one electrostatic system on the former hospital façade, and one static system on the bell tower. The tower also underwent improvements to the bells, renderings, and tile-covered roof. All equipment and cabling were installed unobtrusively to minimize impact on the heritage value.

Results

The high technical skill of the project team, combined with effective coordination of all stakeholders and a continuous respect for the monument’s authenticity and the principles of minimal intervention — prioritizing non-intrusive, reversible, and compatible solutions — allowed for the successful completion of this complex challenge, ensuring the preservation of a highly significant heritage ensemble.