Interventions and works in heritage

Recognition of the cultural value of a good through classification implies increased protection responsibilities, including a rigorous evaluation of the proposals for interventions and works, which must be guided by the preservation of the elements that give the property assets interest.

In Portugal, as in most European countries, interventions in protected cultural goods are submitted to a competent authority, specifically dedicated to the management of cultural heritage. In the case of goods classified as national interest and public interest and in the case of archaeological heritage, this authority is the General Directorate of Cultural Heritage in articulation with the Regional Directorates of Culture.

In this context, the main competences of the Regional Directorate of Culture of the North are:
Issue opinions on works and interventions of public or private initiative in the protection zones of classified or under classification properties;
Issue opinions on studies, projects, reports, works or interventions on goods classified as national monument or public interest, or in the process of classification;
To accompany the actions of safeguarding and valuing the archaeological heritage;
To manage the cultural assets affected by the Regional Directorate of Culture of the North, including conservation and restoration actions in monuments and museum collections;
Provide technical support for interventions or works on cultural assets;

The complexity of the patrimonial universe and the permanent evolution of methodologies make it impossible to establish rules of detail for all situations in advance, but there is a very stable nucleus of principles and consensual guidelines in international doctrine.

Projects must be preceded by a rigorous and comprehensive study. It is essential to have information on the techniques used originally and during subsequent changes, on the phenomena that may have occurred and on the present state of the cultural assets. Projects must involve all relevant disciplines and coordination must be carried out by qualified professionals.

Priority should be given to preventive maintenance and where possible degraded structures should be repaired rather than replaced.

Independently of the typology or scale of the property, the authenticity and integrity of the constituent parts, including the constructive phases belonging to different historical periods, must be respected, avoiding, wherever possible, the removal or alteration of any historical material or of any decorative or Architectural characteristic.

The value of architectural heritage lies not only in its appearance, but in the integrity of all its components, as the unique product of its time. Removal of interior structures is not in accordance with the criteria of conservation, maintaining only the façades.

Preference should be given to techniques that are less invasive. The solutions adopted must be reversible in order to be replaced by more appropriate measures when new knowledge is acquired. When they are not reversible, they should not restrict further interventions. The intervention should leave evidence that can be recognized in the future and the new elements should be distinguished from the original parts.

The intervention must be rigorously documented, in particular by means of audiovisual means, which must record the examinations and analyzes carried out, the techniques, methodologies, materials and treatments applied.