In urban and rural areas of the Andean cities of Ecuador, construction based on earthen technologies has been an important alternative, which are carried out through ancestral customs, such as the minga, which benefit the cohesion of the community. Against this background, the World Heritage City Project of the University of Cuenca (Ecuador) has since the year 2011 undertaken interventions in heritage buildings inspired by the minga, so called Maintenance Campaigns, where the collective efforts of various actors (community, academy and organizations) are joined to recover buildings in highly vulnerable heritage neighborhoods, promoting preventive conservation, maintenance and monitoring of vernacular buildings. The fourth campaign, which was carried out in 2018, took place in the Las Herrerias Street in the historical El Vergel neighborhood of Cuenca, a World Heritage City since 1999. The methodology applied in the previous campaigns was essentially maintained, gaining experience and innovating at every opportunity. As a special aspect, the Las Herrerias Campaign was characterized by the existence of buildings with structures that were already affected by civil works previously carried out, such as re-pavements, drinking water installations, various services, etc. This research proposes to establish conservation strategies of vernacular heritage buildings and to mitigate the effects of poorly carried out civil works. The buildings intervened in the 2018 campaign are taken as reference, specifically those whose damages are the result of civil works. First, a review of bibliographic sources is undertaken to reveal historical data about the neighborhood and the civil works that have been carried out. The research continues with a diagnosis of the condition of the buildings before the Maintenance Campaign. Next, the daily maintenance records and the experience of the participants of the Campaign are investigated to identify and analyze those buildings affected by bad civil works practices and their impact on the damages of their structures. Subsequently, the condition of the buildings after the Campaign is evaluated. Finally, strategies are proposed that must be considered for the interventions of vernacular heritage architecture, built with traditional earth and wood systems. Furthermore, civil works guidelines are defined for these types of interventions. Accordingly, the preservation for future generations of the wealth of material as well as immaterial heritage is encouraged.